Saddleback
Journal of Biology
Mating Desert Pup Fish (Cyprinodon salinus salinus)
Salt Creek, Death Valley, California
Photo by Darryll Sulindro (April 2006)
Published by
Saddleback College Biological Society
Volume 4
Spring 2006
Department of Biological Sciences
Saddleback College
Mission Viejo, CA 92692
Editors, Tony Huntley and Steve Teh
TABLE OF CONTENTS
Peer Reviewed Manuscripts
Author(s)
Rex Roth
&
Mahsa Imani
Leya E. Worcester
&
Chantel J. Jensen
Katia Kiarashpoor
&
Connor O’Mara
Matt Romero
Mark Herrera,
Maryam Shahnavaz
& Wei-Yen Wu
Bita Luhrassebi
&
Daniel K. Park
Vanessa Acosta,
Shallom Han and
Jamie Stevens
R. Michael Kolb
&
Ryan Matthew Whyte
Karl Hodel
&
Reid Sneddon
Matthew Cosley
&
Matthew Michaelian
Kartik Boddupalli
&
Phat Trang
Bahador Etemadi
Nikki Kopan
&
Avisha Tamimi
Tonika Lam
&
Supriya Chaudhary
Title
The Effects of the Synthetic Auxins 2-4D and NAA
on Tomato Fruit Yield
Page
1
Short Term Effects of Fire on Chaparral Brush in
the Santa Ana Mountains
3
Effects of Limited Resources on Growth in the
Sunflower, Helianthus annus
6
The Effect Of Fertilizers Containing High
Phosphorus Content On Flowering in Impatiens
(Impatiens wallerana)
The Effect of Temperature on the Chirp Rate of the
House Cricket (Acheta domestica)
8
10
Delay of Cell Differentiation into Heterocysts in
Anabaena sp. strain PCC7120 Caused by Different
Wavelengths of Light
The Effect of Salt Concentration on Garden Bean
(Phaseolus vulgaris) Germination
12
The Effect of Caffeine on Exercise and Heart Rate in
Homo sapiens
19
The Effect of Carbohydrate Loading on Oxygen
Consumption in White Mice (Mus musculus)
22
The Effects of Lactic Acid Injections on the Tail
Contraction Speed of Freshwater Crawfish,
Procambarus clarkii
The Effects of a Carbohydrate-Electrolyte Solution
on Performance in Endurance Athletes
24
The Effects of Mycorrhizae and Fertilizer on Plant
Growth in Beans, Corn and Peas
The Effect of Nitrogen Fertilizer on the General
Growth Habit in Tomato Plants (Lycopersicon
lycopersicum)
Effect of Pigmentation on Male Betta Fish (Betta
splendens) Interactions
28
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Saddleback Journal of Biology
Spring 2006
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26
31
33
Author(s)
Dean Brown
&
Tom Beckstead
Camilo Avendano
&
Darryll Sulindro
Gregory Dickinson
Kelley Siegert
Christine Knappe*
Maona Yui*
Moriah Harris* and
&
Ladi Boustani*
Lori Sandoval*
Nastaran Aghazadeh
&
Brittney Moyers
Naina Venkatesh
&
Arunkumar Sewchurn
TABLE OF CONTENTS
Peer Reviewed Manuscripts
Title
The Effect of Salinity and Temperature on the
Metabolic Rate of Goldfish (Carassius auratus)
Page
36
The Effect of Antagonist Image Size on Latency to
Aggression in Male Betta Fish (Betta splendens)
38
Absorbance of Cu2+ by yeast (Saccharomyces
cerevisia)
The Effects of Bicarbonate, Glucose, and Caffeine on
Output Volume and pH of Urine
The Effects of Light Wavelength On Seed
Germination and Plant Growth
Effect of Temperature on Lactic Acid Fermentation
in Yogurt
The Ability of Saddleback College Students to
Recognize the Presence or Absence of Caffeine in
Diet Coke
The Effects of Sucrose, Aspartame and Sucralose on
Fermentation in Yeast (Saccharomyces cerevisiae)
The Effect of Light Wavelength on the Growth of
Onions, Allium cepa
41
The Effect of Music on Heart Rate and Lap Time
During Exercise in Humans (Homo sapiens)
59
* These papers are from the Spring Biology 20 Honors Course.
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Saddleback Journal of Biology
Spring 2006
44
49
52
53
55
57
Abstract Issue
Biology 3A abstracts for papers presented at the 3rd Annual Biology 3A/3B Scientific Meeting
(Spring 2006)
The meeting organizers do not assume responsibility for any inconsistencies in quality or errors
in abstract information. Abstracts are in numerical order according to the abstract number
assigned to each presentation. Authorless abstracts appear at the end of all the abstracts,
including non-emailed abstracts. Abstracts begin on page 64.
Note: Author name(s) and abstract titles were printed directly from the abstract form without corrections. The
presentation order was determined by the order in which the emailed abstracts were received. All non-emailed
abstracts presentation order was also determined by the order in which the hardcopy was received.
TABLE OF CONTENTS
Biology 3A Abstracts
Author(s)
Kari A. Prettyman
Mark Reyes
Cody Pai.
Michael Gordon.
Marla M. Fortner &
Elham Zarnegar
Lizbeth M. Barrera &
Felicia Dang
Neima Ghassemian
and Amin Salek
Brian C. Oliver
Yelena I. Martinez
Nicolas Cruz, Callan
Taylor and Sadaf
Bahadoran
Victor Eleazar and
Jennifer Ferrara
Lauretta M. Rustad,
Abdullah Ibish, and
Erik Bosshart
Title
The Effect Of Alcohol-Based and Non-Alcohol-Based
Mouthwash On Growth Of Potential Plaque
Producing BacteriaiIn the Gumline
The Effect of pH on the Surface Breathing of
Goldfish (Carassius auratus)
Concurrent and Delayed Effects of UV Radiation On
Photosynthesis in Spinach Leaves
The Effect of pH on Seed Germination of Radish
(Raphanus sativa)
Overfeeding Goldfish (Carassius auratus) Leads to
Ammonia Production and Behavioral Changes
Effect of Copper Sulfate on Growth of an Aquatic
Macrophyte, Elodea canadensis
The Effect of Wavelength on Crassulacean Acid
Metabolism in Jade Plants
The Effect of Light on Oxygen Production in an
Aquatic plant (Elodea canadensis)
Variation in the Rate of Pollen Germination of the
Asiatic Lily (Lilium sp.) at Different Temperatures
Page
64
The Effect of Polarized Light on the Rate of
Photosynthesis inSpinach Plants (Spinacia oleracea)
The Effect of Red-Colored Plumage on Feeding
Dominance in the Male House Finch (Carpodacus
mexicanus)
66
iii
Saddleback Journal of Biology
Spring 2006
64
64
64
65
65
65
65
66
66
TABLE OF CONTENTS
Biology 3A Abstracts
Author(s)
Title
Sandra Farmand, Heba Learning Capability of Goldfish (Carassius auratus
Elsherif and Azadeh auratus)
Salek
Eugene Kang and
The Effect of Low Partial Pressures on The pH of
Marcus A. Donovan
CAM Plant Leaves
Julia Mann
The Effect of Temperature on Carbon Dioxide
Production in Goldfish (Carassius auratus)
Thien H. Huynh and
In Vitro Analysis of Potato (Solanum tuberosum)
Philip J. Orwig
Tyrosinase Enzyme Kinematics
Kelly Murphy
Effect of Temperature on Garden Bean Germination
Shannel Busuioc and
Effects of Regular Exercising on Metabolic Rate as
Sherry Torng
Measured by the Rate o Carbon Dioxide Production
i Active ad Sedentary Individuals
Kareem D. Sharaf
Opercular Pumping Rates in Small and Large
Goldfish (Carassius auratus)
Yen Tran
The Effect of Ascorbic Acid on the pH of Human
Urine
Zil Patel and
pH Of CAM Plants (Aloe vera) Left in the Dark at
Summer Ford
Different Temperatures for 72 Hours
James D. McMillian
The Effect of Increased Sugar Intake on the Activity
of Mice
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Saddleback Journal of Biology
Spring 2006
Page
66
67
67
67
67
68
68
68
68
69
The Effects of the Synthetic Auxins 2-4D and NAA on Tomato Fruit Yield
Rex Roth and Mahsa Imani
Department of Biological Sciences
Saddleback College
Mission Viejo, CA 92692
The role of auxins, specifically indole acetic acid (IAA), in regulating many aspects of
plant development, including fruit development, has been known since mid century. This
study looked at the effect of synthetic auxins, 2-4 dichlorophenoxyacetic acid, 2-4-D, and
naphthalene acetic acid, NAA, on tomato fruit development. Three groups of tomato plants
had exogenous 2-4-D, NAA, and water sprayed on the leaves, flowers and tomato fruit.
There was a highly significant difference in the yield of tomato fruit in both experimental
groups versus the water group and little tomato development in the water group with a p =
.015 using ANOVA and a Bonferroni post hoc test. There was no significant difference
between the experimental groups. Both treatment groups had nine tomatoes while only one
2.1 gram tomato had developed in the water group in the nine weeks of applications.
Materials and Methods
Thirty two tomato plants were purchased from
Home Depot and were divided into three groups: 10
plants in the water group, 11 plants in the 2-4D group
and 11 in the NAA group. Plants were assigned to the
respective groups equalizing plant size in height and
flower growth. Each plant was sprayed four times
each session with application to the highest leaves,
the flowering parts and to developing tomato fruit. A
standard 1 liter janitorial spray bottle was used for
applications. The control group had water sprayed to
the plants. The 2-4 D was dissolved in 2 ml. of
acetone and then into water at a concentration of
4mg/L. The NAA was likewise dissolved in 4ml of
acetone and then into water at a 10mg/L
concentration. There were three sessions per week for
the first five weeks and four sessions per week the
last three weeks. The plants were grown in the
Saddleback College greenhouse. Cardboard partitions
were placed between groups during exogenous
applications to prevent overspray as plants were close
together due to space limitations in the greenhouse.
Results
After eight weeks of treatment the water group
had one tomato, weighing 2.08 g, whereas both
synthetic auxin groups had a total of nine tomatoes
each. The weight range in the 2-4 D group was 1.09
g to 71.57 g while the NAA group was 11.41 to 52.61
grams. There was a significant difference between
the water and the 2-4 D with a p = 0.015 using
ANOVA and a Bonferroni correction. The
significance between the NAA and water was p = 0.
015. There was no significant difference between
NAA and 2 – 4 D (Figure 1).
Average Weight (grams)
Introduction
Auxins are a group of biochemical compounds
that play an integral role in many aspects of plant
development, including cell enlongation, cell division
and cell differentiation (Went and Thiman, 1937).
The natural auxin, indole acetic acid, IAA, has been
shown to increase the fresh and dry weight of
sunflower apical segments (DeRopp, 1955). It was
followed by the discovery of the regulating role of
auxins in the control of flowering and fruiting
(Leopold, 1956). The synthetic auxin 2hydroxymethyl 4-chlorophenoxyacetic acid (HCPA)
at a concentration of 300 ppm increased the average
weight of tomato fruits in four initial harvests and
HCPA , 2-hydromethyl 4-chlorophenoxyacetic acid
increased the average weight of tomatoes (Castro,
1980). Tomato fruit sets were increased using 4chlorophenoxyacetic acid (4-CPA), (Gianfagna,
1995).
The current study sought to find the effects of
exogenous spraying of the synthetic auxins 2-4-D and
NAA on tomato fruit development.
30
20
10
0
Water
2-4 D
NAA
Figure 1. The 2-4 D and the NAA groups both had a greater
tomato mass than the Water group (p =0. 015). There was no
statistical difference between NAA and 2-4D
1
Saddleback Journal of Biology
Spring 2006
Discussion
After nine weeks of exogenous applications of water
there was one small tomato fruit in the water group,
weighing 2.08 grams. The 2-4D group had nine
tomatoes and one was completely red. All other fruits
were green. The NAA group had one red tomato and
one yellow and the rest were green. Both
experimental groups were statistically different from
the control group (water group ) with a p = 0.015.
Thus, both quantitatively and qualitatively 2-4-D and
NAA increase tomato fruit yield.
In the untreated tomato plant the natural auxin, IAA,
plays an important role in fruit development. It is not
used in agriculture as it is rapidly decomposed by
light and microorganisms. Thus , a number of
synthetic compounds have been found to mimic IAA.
The compound 4- CPA (4-chlorophenoxyacetic acid)
is used to increase the fruit set in tomatoes (Gianfana
1993). Spraying succinic acid-2.2dimethylhydrazide
(SADH) or trimethylammonium chloride (CCC)
increase the yield of tomato plants and causes the
fruits to ripen more uniformly (Castro, 1980). In the
same symposium paper this researcher quotes his
earlier work with Churata-Masca, in which, they
found
that
HCPA,
2-hydroxymethyl
4chlorophenoxyacetic,cid ,at a concetration of 300
ppm increases the average weight of tomato fruits in
four harvests.
The synthetic auxin 2-4 D stimulates uncontrolled
growth in broadleaf plants and as a consequence is
used as a herbicide. However, at the concentrations
(4mg/L) used in this study we found that it stimulates
tomato fruit development. NAA reduces the number
of fruit sets in apples (Gianfagna, 1993), but
increased tomato fruit yield in our current study ( at
10mg/L).
Future prospects for plant growth regulators is
limited due to economic and sociological factors
according to Gianfagna. The research is expensive
due to rigorous testing for the effects on the
environment, as well as, the efficacy of the
compound. In addition, public phobias over growth
regulators, such as Alar (daminozide) discourages
agrichemical concerns from research. Alar was never
reinstated despite the findings of a National Science
Foundation review committee that it posed no health
risk to the general public. The consequences are
significant, Gianfagna (1995) points out the reduced
profitability of growing apples due to pre-harvest
drop. In addition, he alludes to the rapid fruit
softening and poor color development. Refrigeration
is not a satisfactory substitute, as the apples are often
degraded.
Acknowledgments
Thanks to Dr. S.S. Hoffman-Tsay for her technical
publications and recommendations for the
concentrations of NAA and 2-4-D to be utilized in
the current study. In addition, Professor Steve Teh
provided much expertise in the preparation and the
safe use of NAA and 2-4-D, as well as suggestions
to improve the study. Thank you both very much.
Literature Cited
Castro, PRC (1980) Plant Growth Regulators in
Tomato Crop Production. ActaHort. (ISHS) 100:99104.
DeRopp R (1956) Kinetin and auxin activity. Plant
Physiol 31:253-254.
Gianfagna, T (1995) Natural and Synthetic Growth
Regulators and Their Use in Horticultural and
Agronomic Crops. In Plant Hormones: Physiology,
Biochemistry and Molecular Biology, P.J. Davies,
ed., Kluwar, Boston pp 751-773.
Leopold, AC (1958) Auxin Uses in the control of
Flowering and Fruiting. Annual Review Plant Physiol
9:281-310.
Went FW, Thiman KV
Macmillan,NewYork
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Saddleback Journal of Biology
Spring 2006
(1937) Phytohormones.
Short Term Effects of Fire on Chaparral Brush in the Santa Ana Mountains
Leya E. Worcester and Chantel J. Jensen
Department of Biological Sciences
Saddleback College
Mission Viejo, CA 92692
In the event of a fire, plant organisms utilize strategies to maximize fitness
appropriately. Fire encourages grass productivity (r-selected plants) in an area that was
once durable and structurally complex (K-selected plants). This experiment was
emphasized around K and r-selection. We used the point-quarter transect technique on a
recently burned area in Lake Elsinore, California, and compared it to an area similar in
composition. Using a Chi-squared analysis and a succession of importance values, we
summed the Weed and Grass species of each of the burned and unburned areas (one tailed
test of t, p=0.0001). Next, using the most dominant species from each area, Poa sp. and
Erodium sp., a significant difference was found between both study areas (one tailed test of
t, p=0.0020). Despite these significant findings, it was hypothesized that a significant
difference would exist between the types of species found in unburned and burned areas.
Since only r-selected species were found in these areas, the results did not provide support
for our hypothesis.
Introduction
Fires are no stranger to the chaparral regions of
Southern California and have been accepted as a
natural part of the ecosystem. A known fire
community in Southern California is located at the
base of the Santa Ana Mountains. Starting at 3,000
feet, coastal sage scrub inhabits most of this plant
community. These communities can be unstable due
to the likelihood of fires.
Fire is a type of disturbance that can greatly
influence plant diversity. In the absence of fire,
diversity among plants, insects, and animals
decreases. Fire burns in a mosaic that creates a
diversity of species and creates densities within a
plant community. Fire returns nutrients to the soil
where they can be used by plants.
In the absence of recurrent fire, plant production
declines and diversity decreases (Bragg and Hulbert,
1976). Few offspring are produced in unburned areas
due to the prolonged period of parental care. Kselected organisms often have a maximum carrying
capacity among its populations due to density
dependent factors. Such factors include a slower
development, delayed reproduction, and larger plant
size (Kapraun, 2005). K-selection also favors the
investment of resources in long-term development
and reproduces offspring more than once in their
lifetime. However, when a K-selected plant
community experiences a fire, a more complex
environment arises.
In an unstable environment where disturbances
are recurrent, r-selected plant species are often found.
These include species that are short-lived and are
only able to reproduce offspring once in their
lifetime. In the presence of recurrent fire, plant
production attempts to maximize its reproductive
success. These species have population densities that
fluctuate below carrying capacity, are typically
characteristic of early maturity, and use a low amount
of energy to make their offspring (Meehan, 2003). Rselection is also associated with rapid development,
high population growth rate, early reproduction, and
small plant size (Kapraun, 2005).
The objective of this study was to compare r and
K-selected plant species in burned and unburned
regions. We believe that a significant difference
exists between the types of species found in unburned
areas (K-selected species) and burned areas (rselected species).
Materials and Methods
In the city of Lake Elsinore, California, the Santa
Ana Mountains recently experienced a fire in June or
July of 2005 at the corner of Ortega Highway and
Grand Avenue. One side of the highway represented
the burned area, and the other represented the
3
Saddleback Journal of Biology
Spring 2006
unburned. Using the point-quarter transect technique,
five 100-meter transect lines were laid out in each
area. Each transect line was five meters apart, facing
Northwest.
Every ten meters represented one sampling
interval and was divided into four quadrants. The
plant closest to the origin of the four quadrants was
measured, along with the diameter of the plant itself.
Results
We recorded thirteen plant species in the two
study areas, but two of these species (Poa sp. and
Erodium sp.) occurred in both areas. Importance
values were calculated and sorted from low to high
values. The two highest importance values from the
unburned area were Lolium sp. (IVi = 1.6) and Oxalis
corniculata (IVi = 1.12) (Table 1). Poa sp. (IVi =
0.94) and Erodium sp. (IVi = 0.76) represent the two
highest importance values from the burned area
(Table 2). These species are designated as the two
most dominant species to occur in each study area.
Table 1. Importance Values are sorted in ascending
order for all plant species in the unburned area
(Number of points sampled, k = 50; number of
quadrants, 4k=200)
Species
ni
RD
Taraxacu
m
officionale
Gnaphaliu
m sp.
Green
annuals
Vitis
girdiana
Amsinckia
intermedia
Thistle
species
Isocoma
menziessi
Mollugo
verticillata
Vine
species
Erodium
sp.
Poa sp.
6
2
1
3
3
8
6
21
5
64
71
RFi
RCi
IVi
0.0
3
0.04
8
0.03
3
0.011
0.0
1
0.0
1
0.0
2
0.0
2
0.0
4
0.0
3
0.1
1
0.0
3
0.3
2
0.3
6
0.01
1
0.01
1
0.01
1
0.03
5
0.02
4
0.05
9
0.13
2.43
E-05
0.00
2
0.01
7
0.00
5
0.03
7
0.10
2
0.02
2
0.38
0.021
0.17
0.76
0.22
0.94
i
0.03
5
0.27
0.36
0.023
0.048
0.06
0.101
0.19
Table 2. Importance Values are sorted in ascending
order for all plant species in the burned area
(Number of points sampled, k = 50; number of
quadrants, 4k=200)
Species
ni
RD
Poa sp.
2
Taraxacu
m
officionale
Erodium
sp.
Oxalis
corniculat
a
Lolium sp.
1
18
165
RCi
IVi
0.0
1
0.0
1
0.01
3
0.01
3
0.00
1
0.01
3
0.024
0.0
7
0.0
9
0.16
0.236
0.17
0.00
6
0.86
1.12
0.8
3
0.65
0.12
1.6
i
0.036
All Weed species and Grass species from each
study area were totaled and compared using a Chisquared analysis. From the unburned area, Weed
species included Erodium sp. (ni=14), Oxalis sp.
(ni=18), and Taraxacum officionale (ni=1). In
addition, the most predominant Grass species from
this area included Poa sp. (ni=2) and Lolium sp.
(ni=165) (Table 3). Totals from the burned area for
Weed species included Thistle species (ni=8),
Erodium sp. (ni=64), Mollugo verticillata (ni=21),
Amsinckia intermedia (ni=3), Vine species (ni=5), and
Taraxacum officionale (ni=6). Poa sp. was the only
Grass species found within the burned area. A
significant difference was found between all Weed
and Grass species (one tailed test of t, p=0.0001).
While Poa sp. and Erodium sp. occurred in the
unburned and burned areas, another Chi-squared
analysis was performed to see if there was a
difference between the two areas. There was
significantly more Erodium sp. and Poa sp. in the
burned area than the unburned (one tailed test of t,
p=0.0020) (Table 4).
Table 3. Comparison of Weed species and Grass
species in the burned and unburned areas. Chisquared analysis (2x2) was performed with a onetailed test of t (p=0.0001).
0.26
0.45
14
RFi
Burned
Unburned
Total
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Saddleback Journal of Biology
Spring 2006
Weed
species
107
33
140
Grass
species
71
167
238
Total
178
200
378
Table 4. Comparison of the two most common plants
(Erodium sp. and Poa sp.) in the burned and
unburned areas. Chi-squared analysis (2x2) was
performed with a one-tailed test of t (p=0.0020).
Burned
Unburne
d
Total
Erodium
sp.
64
14
Poa sp.
Total
71
2
135
16
78
73
151
Discussion
Density dependent interactions of plant species
(K-species) can suffer a loss after fires when rselected species quickly produce offspring. After
severe fire, the loss of plant nutrients and
destabilization of soils can inhibit plant regeneration
(Meyer, et al., 2004). Severe fire can also cause
vaporization of organic substances in the upper soil
layers. Light and nitrogen have a higher availability
for K-selected plants due to their larger mass and
capacity to uptake the majority of nutrients
(McCarron and Knapp, 2003). In a previous study
done by Knapp (1986), he found that at burned sites,
grasses responded positively to fire by increasing
biomass and uptake of nitrogen by as much as 53%
compared to the unburned sites. Through burning,
there is always an increase in light available to
organisms (Blair, 1997). As a result, when a fire
occurs, K-selected plants are minimized allowing for
a greater abundance of light to low-lying, r-selected
plants.
Larger plant size is associated with K-selection
that favors slower development and delayed
reproduction. Smaller plant size signifies r-selection,
which favors rapid development, high population
growth rate, and early reproduction (Kapraun, 2005).
R-selected organisms live in risky or disturbed
environments where they produce many offspring at
once (Meehan, 2003). These disturbances can include
debris, human recreation, and natural disasters. Fire
is a disturbance common to coastal sage scrub.
At both sites, the totaled Weed and Grass species
were compared, suggesting that there is a difference
between the dominant plant species in the burned and
unburned chaparral. More specifically, Erodium sp.
and Poa sp. occurred at both sites and was found to
be significantly different. This experiment was
conducted to test the hypothesis that a significant
difference exists between the types of species found
in unburned areas and burned areas.
Due to the recent rainfall in this community,
many plant species have sprouted, which corresponds
to our findings of Weed and Grass species (r-selected
species). Typically, these plants have underground
buds for recovery after a disturbance. Our data
suggest that fire induces these buds to resprout and
stimulate r-selection. Indeed, disturbance by fire may
have actually accelerated an increase in plant
diversity.
A high abundance of Weed and Grass species
were found in the burned and unburned areas.
However, we did not find any K-selected species
among the transect areas. The most accessible burned
area was characteristic of a meadow, thus the
unburned area needed to be similar in composition.
As a result, no K-selected plants were found within
the burned and unburned sampling area. We were not
able to support our hypothesis.
Literature Cited
Blair, J M. 1997. Fire, nitrogen availability, and plant
response in grasslands: a test of the transient maxima
hypothesis. Ecology 78: 2359-2368.
Bragg, T B and Hulbert, L C. 1976. Woody plant
invasion of unburned Kansas bluestern prairie.
Journal of Range Management 29: 19-24.
Kapraun, D F. 2005. Nuclear DNA Content
Estimates in Multicellular Green, Red and Brown
Algae: Phylogenetic Considerations. Annals of
Botany 95(1): 7-44.
Knapp, A K. 1986. Postfire water relations,
production, and biomass allocation in the shrub, Rhus
glabra, in tallgrass prairie. Botanical Gazette 147:
90-97.
McCarron, J K and Knapp, A K. 2003. C3 shrub
expansion in a C4 grassland: positive post-fire
responses in resources and shoot growth. American
Journal of Botany 90: 1496-1501.
Meehan, T D and George T L. 2003. Short-term
effects of moderate- to high-severity wildfire on a
disturbance-dependent flycatcher in northwest
California. The Auk 120(4): 1102-1113.
Meyer, V F, Redente, E F, Barbarick, K A, Brobst, R
B, Paschke, M W, and Miller, A L. 2004. Ecosystem
Restoration. Journal of Environmental Quality 33:
873-881.
5
Saddleback Journal of Biology
Spring 2006
Effects of Limited Resources on Growth in the Sunflower, Helianthus annus
Katia Kiarashpoor and Connor O’Mara
Department of Biological Sciences
Saddleback College
Mission Viejo, CA 92692
Many factors play a role in determining the survival of organisms. For example, living
organisms need a source of food and nutrients to grow and reproduce. This study examined
how well sunflowers grow when competition exists for limiting resources in regards to the
density given for growth. Fifteen sunflower seeds were planted in ten separate pots, with
five pots containing a single seed and the remaining five pots containing two seeds spaced
five to six centimeters apart. All pots were placed together receiving the same amount of
water and an equal amount of sun for a period of one month. After one month the stem
thickness and height of the plants were recorded. The single plants grew taller (12.00 cm vs.
10.35 cm) and had thicker stem diameters (4.20 mm vs. 3.3 mm) than the double plants
grown at a higher density. However, the results showed no significant difference between
the height p = 0.198 (two-tailed t-test), and stem diameters between the two test groups of
Helianthus annuus p = 0.169 (two-tailed t-test). Therefore, the experiment did not validate
the hypothesis that the single seed would grow significantly greater than the paired seeds
Introduction
Materials and Methods
All living organisms, including plants require a
certain amount of resources for growth and
reproduction. Whether or not their needs are met
depends on the resources they obtain from their
environments. Minimal resources may result in
stunted growth and perhaps death. The resources
plants compete for include water, sunlight, nutrients
such as nitrogen and phosphorus, and space for
growth (Stoll and Bergius, 2005). Therefore, all
plants compete amongst one another in one way or
another when there are limited resources (Falik,
2003). Organisms of the same species tend to
compete more for the same essential resources, rather
than those of a different species (Berger et al., 2003).
Experiments have established that moderate to strong
competition exists between plants in a wide variety of
communities (McGraw and Chapin, 1989).
The objective of this experiment is to analyze the
growth of Helianthus annuus (sunflower) when
planted at varying densities. This study was inspired
after noticing variation in plant growth and success as
a result of the competition process. Any factor that is
essential for growth and reproduction is a limiting
factor (Reynolds, 2005). In this experiment the
limiting factor is surface area for plant growth. The
hypothesis is that the single seeds will grow
significantly greater than the paired seeds.
For this experiment, a pack of Aster Heliantus
annuus seeds were purchased from Ace Hardware in
San Clemente, CA. Fifteen seeds were then planted
in ten 15.24 cm plastic pots containing Miracle-gro®
garden soil for fruits and vegetables enriched with
Miracle-gro® continuous release plant food. Five of
the ten pots each contained a single seed in the center
of the soil; the other five pots each contained two
seeds spaced five to six centimeters apart. All ten
pots were set beside each other receiving 500 mL of
Kirkland® water every three days and nine hours of
sun light and fifteen hours of natural dark everyday
for one month. The seeds were planted on February
18, 2006 and the data were recorded on March 18,
2006. A caliper was used to take measurements. The
plants were kept on the porch in Laguna Niguel, Ca
facing south. A handful of Multiguard® Slug and
Snail Killer was sprinkled on and around all the
plants once a week to prevent harm.
Results
After one month, the difference in growth of the
Helianthus annuus plants was not significant enough
to support the hypothesis. The plants grown close
together at a high density (1 plant/90.7 cm2) did not
grow as well as those planted farther apart at a lower
density (1 plant/181.5 cm2). The single plants grew
taller (12cm.vs. 10.35 cm. {Figure 1}) and had
thicker stem diameters (4.2 mm. vs. 3.3 mm. {Figure
6
Saddleback Journal of Biology
Spring 2006
2}) than the double plants grown at a higher density.
Although the low density plants had better growth
results than the high density plants, the difference
was proven insignificant by a two tailed, two-sample
t-test assuming equal variances. The results for the
height of Helianthus annuus in the two test groups
are as follows {P (T<=) two-tail = 0.198}. Also, the
t-test showed that there was no significant difference
between the stem diameters for the two test groups of
Helianthus annuus {P (T<=) two-tail = 0.169}.
12.5
Height 12
(cm) 11.5
12
11
10.35
10.5
10
9.5
Single
Double
Figure 1. Mean height (after one month of growth) of
five single planted sunflower plants vs. height of ten
sunflower plants grown in pairs (cm).
5
4.2
Stem
4
Diameter
(mm)
3.3
3
resources when planted by themselves or burdened
by competition for space and resources when planted
in pairs. Similar research conducted by Reynolds et
al. (1997) on the coexistence and competition
between species produced data that was interpreted as
evidence of moderate to strong competition between
plants for limited resources in a wide variety of
undisturbed habitats.
For Helianthus annuus and all other plants,
limited resources are sunlight, water, space for
growth, and soil with nutrients such as nitrogen and
phosphorus. All of these resources were given to each
plant equally except for the space to grow which was
more limited for the double planted pots than for the
single planted pots. The plant density for the single
planted pots was 1 plant/181.5 cm2, compared to a
plant density of 1 plant/90.7 cm2 for the double
planted pots. Individual plant growth is greatly
effected by the plant density in the area which the
plant is grown. If the density is too high, there will be
much more competition between plants which results
in less growth and a lower survival rate. Often, plant
competition will lead to natural patterns where the
plants space themselves evenly in the landscape
(Stoll and Bergius, 2005). Every plant has an optimal
density for growth and survival. In natural habitats,
the plants form spacing patterns which enhance their
chance of survival.
Since the single plants did not grow
significantly better than the double plants, the
optimal density for Helianthus annuus would likely
be greater than or equal to the density of the double
planted pots in our experiment (1 plant/90.7 cm2).
Literature Cited
Berger U, Hildenbrandt H, and Grimm V. Agerelated decline in forest production: modeling the
effects of growth limitation, neighbourhood
competition and self-thinning. The Journal of
Ecology. 92 (5): 846-853.
2
1
0
Single
Double
Figure 2. Mean stem diameter (after one month of
growth) of five single planted sunflower plants vs.
stem diameter of ten sunflower plants (mm)
Discussion
The data for growth of Helianthus annuus in
high and low densities showed that there is no
significant difference between sunflower plants that
have been planted by themselves and sunflower
plants that have been planted in close proximity to
others (5-6 cm). The Helianthus annuus plants were
neither benefited by the abundance of space and
Falik O, Reides P, Gersanim M, and Novoplansky A.
2003. Self/non-self discrimination in roots. The
Journal of Ecology. 91 (4): 525-532.
McGraw J and Chapin S. 1989. Competitive ability
and
adaptation to fertile and infertile soils in two
Eriophorum species. Ecology. 70 (3): 737-751.
Reynolds H, Hungate B, Chapin F, and D'Antonio C.
1997. Soil heterogeneity and plant competition in
annual grassland. Ecology. 25 (3): 228-247.
7
Saddleback Journal of Biology
Spring 2006
Reynolds J and Ford E. 2005. Improving competition
representation in theoretical models of self-thinning:
a critical review. The Journal of Ecology. 93 (2):
362-372.
Stoll P and Bergius E. 2005. Pattern and process:
competition causes regular spacing ofindividuals
within plant populations. The Journal of Ecology. 93
(2): 395-403.
The Effect Of Fertilizers Containing High Phosphorus Content On Flowering in Impatiens
(Impatiens wallerana)
Matt Romero
Deaprtment of Biological Sciences
Saddleback College
Mission Viejo, CA, 92692
The purpose of the experiment was to understand the relationship between phosphorus
content in soil and the ability for a plant to produce flowers. In this case, the effects were
tested on impatiens (Impatiens wallerana). Each experimental group contained twelve small
plants. The groups consisted of the control group, the low phosphorus group, and the high
phosphorus group. The nitrogen-phosphorus-potassium (NPK) level for the low
phosphorus group was 20-20-20 and the NPK level for the high phosphorus group was 1154-4. Each group was consistently watered every other day with a half gallon of water.
Every ten days, both experimental groups were fertilized. This was completed seven times
over the course of ten weeks. It was hypothesized that a fertilizer with high amounts of
phosphorus would yield more flowers in the tested group. The results were analyzed with
an ANOVA test and it was found that there was a significant difference between the means
(p = 0.002). Therefore, the hypothesis that high phosphorus levels in soil would produce
more flowers was congruent with the results.
Introduction
It is commonly known throughout the
horticulture industry that phosphorus aids a flowering
plant in its ability to produce flowers. Fertilizers
contain a ratio of nitrogen, phosphorus, and
potassium. Nitrogen aids in development of leaves
and branching systems and potassium aids in the
proper development of root systems in plants.
Previous studies have shown that other methods can
be used to aid a plant in low phosphorus situations. It
has been determined that the over expression of
mitochondrial citrate synthase in Arabidopsis
thaliana improved the growth in a phosphoruslimited soil condition (Koyama, 2000). Another study
also stated to have determined that increased levels of
phosphorus led to an increased amount of phosphorus
storage in the winter when phosphorus levels tend to
be lower in the certain Mediterranean region where
the study had taken place (Shane, 2004). An
additional study that has shown affects of phosphorus
levels was an experiment showing that plants’ rapid
gene response to phosphorus deficiencies is caused
by sensors in the root system (Wang, 2002). A recent
study of phosphorus availability effects on carbon
economy showed that a lower amount of phosphorus
led to the significantly greater amount of net carbon
assimilation on root respiration (Nielson, 2001). It
can also be noted that an increased activity of
proteins pertaining to alternative respiratory and
photosynthetic pathways has been observed during P
deficiency (Hammond, 2004). After reviewing these
studies, the biological importance of phosphorus
levels in soil influenced the experiment to take place
on a group of impatiens.
Materials and Methods
All work was configured in a spacious area of
concrete in direct sunlight. The study was started
with 36 seedlings of Impatiens wallerana in total and
the plants were divided into three groups of 12. The
three groups were the control group, low phosphorus
group, and the high phosphorus group. The nitrogenphosphorus-potassium (NPK) level for the low
phosphorus group was 20-20-20 and the NPK level
for the high phosphorus group was 11-54-4. The
experiment was held over a ten week period. In the
ten week period, the experiment groups were each
fertilized every ten days, adding up to seven
8
Saddleback Journal of Biology
Spring 2006
fertilizations. According to the instructions on each
fertilizer, a tablespoon of fertilizer is to be mixed
with a half gallon of water. The control group
received a half gallon of water with no fertilizer.
Regular watering was performed every other day to
ensure maintained moisture in the soil. At the end of
the ten week period, flower numbers for each plant
were recorded. Flower distribution was recorded by
counting the amount of fully developed flowers in an
individual plant.
Results
The results obtained from the experiment are
that of what was hypothesized. The mean number of
flowers, shown in Figure 1, for the control, low
phosphorus, and high phosphorus groups were 6.7,
5.0, and 9.3 respectively. The high phosphorus plant
group was able to produce a significantly greater
number of flowers than the low phosphorus group
and the control group. Therefore, it can be stated that
there was a significant difference between the means
of the groups. Statistical analysis was performed with
ANOVA using a 95% confidence interval and a p
value of .002 was calculated.
10
phosphorus aided in increased storage levels in
phosphorus deficient periods (Shane, 2004). The
2002 experiment led by Wang suggested that low
phosphorus levels detected by the root system of a
plant triggered rapid gene responses to aid in the
deficiency. In a period of low phosphorus situation, a
plant will often use carbon for production of
heterotrophic structures, such as the roots, rather than
photosynthetic structures (Nielson, 2001). Each of
the studies has proved to be very important to the
understanding of the results from the experiment
performed. The plant’s flowering system thrives on
high phosphorus situations but can also provide
alternative methods for low phosphorus situations,
but will yield a lower flower count. The main
purpose of this experiment was to test the differences
in flower growth between low and high phosphorus
levels, but differences in stem and branch systems
were also detected. In the low phosphorus group, the
fertilizer contained a higher percentage of nitrogen
and this caused the plant group to have a denser
system of branches and leaves. The study proved to
aid in understanding the importance of phosphorus in
the NPK content in fertilizers and showed how a high
amount of phosphorus can yield a significantly
greater number of flowers.
9
8
Literature Cited
7
6
Control
5
4
Low Phosphorus
High Phosphorus
3
Hammond, J., Broadley, M., White, P. 2004. Genetic
Responses to Phosphorus Deficiency. Annals of
Botany. 94(3):323-332.
2
1
0
Control
Low Phosphorus
High Phosphorus
Figure 1. Bar graph showing the mean number of
flowers for the control, low phosphorus, and high
phosphorus groups in a study of flower growth in
differing phosphorus level situations.
Discussion
The results from the experiment suggest that
soil with high amounts of phosphorus can lead to the
production of more flowers. This is comparable with
previous studies that have tested the importance of
phosphorus levels in soil. As the 2000 study by
Koyama indicated, the low levels of phosphorus in
soils influenced the researchers to experiment and
suggest that the over expression of mitochondrial
citrate synthase improved growth in Arabidopsis
thaliana. It has also been made known that in
phosphorus deficient soils proteins for alternative
respiratory and photosynthetic pathways have been
presently active (Hammond, 2004). A 2004
experiment led to suggest that increased levels of
Koyama, H., Kawamura, A. 2000. Overexpression of
Mitochondrial Citrate Synthase in Arabidopsis
thaliana Improved Growth on a Phosphorus-Limited
Soil. Plant and Cell Physiology. 41(9):1030-1037.
Nielson, K., Eshel, A., Lynch, J. 2001. The effect of
phosphorus availability on the carbon economy of
contrasting common bean (Phaseolus vulgaris L.)
genotypes. Journal of Experimental Botany.
52(355):329-339.
Shane, M., McCully, M. 2004. Tissue and cellular
phosphorus storage during development of
phosphorus toxicity in Hakea prostrata (Proteaceae).
Journal of Experimental Botany. 55(399):1033-1044.
Wang, Y., Garvin, D. 2002. Rapid Induction of
Regulatory and Transporter Genes in Response to
Phosphorus, Potassium, and Iron Deficiencies in
Tomato Roots. Evidence for Cross Talk and
Root/Rhizosphere-Mediated Signals. Plant
Physiology. 130:1361-1370.
9
Saddleback Journal of Biology
Spring 2006
The Effect of Temperature on the Chirp Rate of the House Cricket (Acheta domestica)
Mark Herrera, Maryam Shahnavaz, and Wei-Yen Wu
Department of Biological Sciences
Saddleback College
Mission Viejo, California USA
Male crickets make the chirping sound when they want to attract females, fight with intruding
males, and sounding an alarm. They chirp by rapidly sliding one wing over the other. In
crickets, muscular activities tend to vary with the temperature, so it is predicted that the
frequency of the chirping sound will increase with the temperature. The purpose of the
experiment is to determine if the house crickets chirp faster in higher temperature. The chirping
frequency of sixteen house crickets was studied; eight in ambient (21oC) and eight in a higher
temperature (30oC). The frequency of chirping was recorded for each group. The hypothesis was
that the frequency of the chirping sound would increase in a higher temperature. The average
chirping frequency under ambient temperature (21oC) was 367 chirps per five minutes and in
high temperature (30oC) it was 428 chirps per five minutes. The result of the experiment
supported the hypothesis, under a high temperature, the frequency significantly increased
compare to the ambient temperature (p = 2.09x10-20 using the unpaired, one tailed t-test).
Introduction
Crickets are among the most ubiquitous insect
species in the world. Different species of crickets
inhabit virtually every habitat on earth. House
crickets are closely related to grasshoppers and
locusts, and like them they have hind legs that are
modified for jumping. The adults are about 2 cm
long, and pale brown with a black pattern on the head
and thorax. They have long, slender antennae that are
much longer than the body. The females have a long,
slender ovipositor projecting from their abdomen for
egg-laying (Hendrick and Weber, 1998). House
crickets prefer to live in warm, moist environments,
and they are more active at night (Prestwich and
Walker, 1981).
Each female can lay an average of 728 eggs with
the nymphs resembling the adults except being
wingless. The nymphs reach adulthood in
approximately 60 days. Crickets are omnivores and
feed on plant and animal materials, including insects
and their eggs. They are commonly raised as fish bait
and pet food. Unlike the females, only the males
make the chirping sound (Hendrick and Weber,
1998). The sounds are made when they want to
attract females, fight with intruding males, and sound
an alarm to others.
The male crickets chirp by rubbing a sharp edge
known as the scraper at the base of one front wing
along a file-like ridge on the bottom side of the other
front wing, resulting in a series of sounds (Stephen
and Hartley, 1995). The faster they move their
wings, the higher the chirping sound that is produced.
Scientists have noticed that crickets move their wings
faster in warm temperatures than in cold temperatures
(Prestwich and Walker, 1981).
This study will test the hypothesis that the
frequency of the chirping sound in a higher
temperature (30oC) will be faster than in ambient
temperature (21oC).
Materials and Methods
A total of 16 crickets were purchased at PetSmart
(Aliso Viejo, CA) with an average body length of 1.7
centimeters for males and 2.2 centimeters for
females. The crickets were separated into two groups
of eight, each group containing four males and four
females. Each group was acclimated in a different
environmental temperature for 48 hours prior to the
experiment. The two temperatures consisted of
ambient temperature (21oC) and a high temperature
(30oC).
A portable heater, Presto HeatDish Plus Footlight,
was used to maintain the temperature at 30oC and
placed in the bedroom closet while the second group
of crickets were set in a separate bedroom for the
ambient temperature, 21oC. Each test consisted of
pairs of crickets, one female and one male. The pairs
of crickets were placed in a 15cm x 15cm x 15cm
plastic container while the remaining crickets were
placed in a 25cm x 25cm x 15cm plastic container.
All crickets were fed ad libitum with Fluke’s Cricket
Quencher purchased at PetSmart, Aliso Viejo, CA.
10
Saddleback Journal of Biology
Spring 2006
After the acclimation period, each group of
crickets’ chirping rate was measured by counting the
number of chirps at 5 minute intervals. One count for
each pair was recorded at the same period of the day,
between 10:00 am and 11:00 am PST, for a total of 5
days. The data were analyzed using Microsoft Excel.
Results
Of the 20 tests for each temperature, the chirping
rate for the crickets acclimated at the ambient
temperature (21oC) was an average of 367± 10
chirps per 5 minutes chirps, and the mean for the high
temperature (30oC) was 428± 11 chirps per 5
minutes chirps (Figure 1).
There was a significant difference between the
crickets’ chirping rates between the ambient
temperature (21oC) and the high temperature (30oC).
The chirping rate significantly increased as the
temperature increased.
Using unpaired, one tailed t-test, the p value for the
crickets’ chirping rate between the two temperatures
the p value was significantly less than 0.05
(p=2.09x10-20 ).
500
Number of chirps (per 5 minutes)
428 ± 11 chirps
400
367 ± 10 chirps
300
200
100
0
21
30
o
Temperatature (C )
Figure 1. The average chirping rate of crickets in two different
temperatures for a total of 20 test at each temperature. Result
showed significant difference for the chirping rate between the
two groups ( p=2.09 x 10
-20
factors affecting the sounds have been of interest to
researchers for some time. Of the many factors
investigated, temperature has been by far the most
influential (Gray and Cade, 1999). Additionally, the
female responsiveness to male pulse rates changes
similarly with the temperature (Pires and Hoy, 1992).
Temperature affects the rates at which crickets
move their wings. Therefore; it influences the
frequency of the chirping sound. Cricket is an
ectoderm and possesses a high surface-to-volume
ratio. Its metabolic rate is relatively slow and so its
internal temperature reflects the environmental
temperature (Angilletta et al, 2002). Muscular
activities like chirping tend to vary with the
temperature, so the rate of wing closure increases as
the temperature increases and it is predicted that the
frequency of the chirping sound will increase with
the temperature.
The process of sliding one wing over another wing
requires a sufficient amount of energy for muscle
contraction. The Sliding Filament Model indicates
the contraction of the muscle fiber is primarily based
on the shortening of the sarcomere which is based on
the interaction between actin and myosin. This
interaction is triggered by hydrolysis of ATP
(Campbell and Reece, 2005).
The chemical reactions that occur in endotherm
species proceed at a constant rate, and therefore we
can make reliable predictions concerning the qualities
or characteristic of them. However; for ectotherm
species such as crickets, chemical reactions,
including those involved in muscle contraction speed
can occur only as fast or as slow as the surrounding
temperature will allow (Angilletta et al, 2002). As
temperature increases, the crickets’ metabolic rate
increases therefore allowing for an increase in muscle
contractions for a higher frequency of chirping. On
the other hand, a decrease in temperature will have
the opposite effect on the cricket.
The hypothesis that the chirping rate of the House
cricket (Acheta domestica) will be greater in a high
temperature (30oC) than the chirping rate at an
ambient temperature (21oC) was observed and
supported by this study. This study may provide
insight to the crickets’ adaptation methods to the
changes in environment or seasons.
, unpaired one tail t-test).
Discussion
Male crickets make their chirping sounds by
rapidly sliding one wing over the other. The faster
they move their wings, the higher the frequency of
the chirping sound that is produced. Since calling
song is very important for male reproductive success,
Literature Cited
Angilletta MJ, Niewiaroski PH, Navas CA. 2002.
The evolution of thermal physiology in ectotherms.
Journal of Thermal Biology. 27: 249-268.
Campbell N, Reece J. 2005. Biology, 7th edition. San
Francisco, CA: Benjamin Cummings. 1231 p.
11
Saddleback Journal of Biology
Spring 2006
Gray D, Cade W. 1999. Sex, death and genetic
variation: natural and sexual selection on cricket
song. Science. 266:707-709.
Hendrick A, Weber T. 1998. Variance in female
responses to the fine structure of male song in the
field cricket (Gryllus integer). Behavior Ecology. 9:
582-591.
Prestwich KN, Walker TJ. 1981. Energetics of
singing in crickets: Effect of temperature in 3 trilling
species (Orthoptera: Gryllidae). Journal of
Comparative Physiology B. 143: 199-212.
Stephen R, Hartley J. 1995. Sound production in
crickets. Journal of Experimental Biology. 198:
2139-2140
Pires A, Hoy R. 1992. Temperature coupling in
cricket acoustic communication. Journal of
Comparative Physiology. 171:79-92.
.
Delay of Cell Differentiation into Heterocysts in Anabaena sp. strain PCC7120 Caused
by Different Wavelengths of Light
Bita Luhrassebi and Daniel K. Park
Department of Biological Science
Saddleback College
Mission Viejo, CA 92692
Heterocystous cyanobacteria are composed of vegetative cells and heterocysts,
involved in oxygenated photosynthesis and nitrogen fixation, respectively. Certain
vegetative cells are predetermined to differentiate into heterocysts. Although several
factors influencing heterocyst differentiation have been determined, the overall
pathway for cell differentiation into heterocysts is not yet fully understood. In this
study, the effect of different wavelengths of light on the formation of heterocysts in
Anabaena sp. strain PCC7120 was observed. We exposed 4 sets of algal cultures
subjected to the same ambient temperature and light intensity to blue (475 nm), green
(510 nm), red (650 nm) and white light for 15 days. We found that there was a
significant difference in the average number of vegetative cells separating two adjacent
heterocysts between algal cultures exposed to white and red light as well as white and
blue light. The average number of vegetative cells separating adjacent heterocysts for
white light remained consistent (12 cells) over the course of 15 days while that of red,
green, and blue lights gradually increased. At the end of day 15, the average number of
vegetative cells was the following: red = 36 cells, green = 31 cells, blue = 37 cells. These
results suggest that differentiation of vegetative cells into heterocysts is somewhat
inhibited and therefore, the signaling pathway involved in heterocyst formation favored
the preservation of vegetative cells.
Introduction
Cyanobacteria are the only group of organisms that
are able to reduce both combined nitrogen (N2) and
carbon (from CO2) in aerobic conditions.
Consequently,
cyanobacteria
have
formed
indispensable symbiotic relationships with plants by
making nitrogen available to autotrophic plants in the
forms of nitrites, nitrates, and ammonia.
Filamentous cyanobacteria such as those from
generas Anabaena and Nostoc can reduce nitrogen (via
nitrogen fixation) as well as carbon (via
12
Saddleback Journal of Biology
Spring 2006
photosynthesis). However, these two processes are
incompatible with each other because the activity of
nitrogenase, the enzyme which catalyzes the reduction
of nitrogen to ammonia, is inhibited by the presence of
oxygen (Fay and Cox, 1967; Wolk et al., 1994). In
Anabaena, differentiated cells called heterocysts
provide the anaerobic environment necessary for
nitrogen fixation while vegetative cells continue to
carry out oxygenated photosynthesis. Filaments of
Anabaena show patterned differentiation of 10-20
vegetative cells separated by adjacent heterocysts.
During cell differentiation, certain genes are
activated while other genes are inactivated. Current
research has identified several factors regulating the
process of cell differentiation into heterocysts. Studies
have found that under conditions of N2 deprivation,
increased concentrations of free Ca2+ ions are necessary
for heterocyst development (Torrecilla et al., 2004;
Zhao et al., 2005). Another study provided molecular
evidence that inhibition of cell division suppresses
heterocyst formation but does not affect the
accumulation of the 2-oxoglutarate (2-OG) metabolic
signal
responsible
for
triggering
heterocyst
differentiation (Sakr et al., 2006). 2-OG provides the
carbon skeleton for incorporating inorganic nitrogen
(Li et al., 2003). Furthermore, increased levels of 2-OG
has been observed within cells starved of N2 (MuroPastor et al., 2001; Laurent et al., 2005). But the fact
that 2-OG has no influence on heterocyst
differentiation during inhibition of cell division
suggests that cell division and accumulation of 2-OG
are independent of each other. Evidence from this
study also suggests that differentiation of vegetative
cells into heterocysts is dependant on cell division.
While many non-heterocystous cyanobacteria are
able to fix nitrogen (Bergman et al., 1997), the current
study focuses on a heterocystous cyanobacterium,
Anabaena sp. strain PCC7120. In Anabaena sp. as well
as other heterocystous cyanobacteria, vegetative cells
and heterocysts form a symbiotic relationship.
Vegetative cells rely on heterocysts for fixed nitrogen
(mainly ammonia) if an organic nitrogen source is not
available, while heterocysts rely on vegetative cells for
fixed carbon. Because fixed carbon is produced from
the Calvin Cycle of photosynthesis, exposure of
Anabaena sp. to different wavelengths of light versus
the formation of heterocysts are related indirectly.
How well cyanobacteria absorb a particular
wavelength of light depends on the type of pigments
they possess. Anabaena sp. contains photosynthetic
pigments
called
phycobilins
embedded
in
phycobiliproteins. The captured light energy is passed
on to chlorophyll during photosynthesis to ultimately
produce fixed carbon and ATP. In this paper, we
explore the effect of different wavelengths of light on
photosynthesis and patterned differentiation into
heterocysts.
Materials and Methods
Heterocyst formation was monitored for 15 days
using algal cultures exposed to red, blue, green, and
white light. The live heterocystous cyanobacteria used
in this experiment were Anabaena sp. strain PCC7120
(Science Kit & Boreal Laboratories). The medium in
which the algal culture was grown in was Bristol’s
Solution modified by Bold (1949). Preparation of this
solution included six stock solutions, 400 ml in
volume, each containing one of 10.0 g NaNO3, 1.0 g
CaCl2·2H2O, 3.0 g MgSO4·7H2O, 3.0 g K2HPO4, 7.0 g
KH2PO4, or 1.0 g NaCl. 10 ml of each stock solution
was added to 940 ml of glass-distilled water. A drop of
1.0% FeCl3 solution was then added to this solution.
To mimic light exposure at different wavelengths,
red (650 nm), blue (475 nm), and green (510 nm)
cellophane were used to cover sets of algal cultures.
Saran wrap on a fourth set of algal culture was used to
allow for a control group grown under white light (400
– 700 nm).
Each set of algal culture consisted of five test
tubes each filled with five ml of Anabaena sp. strain
PCC7120 in Bristol’s Solution (modified by H.C.
Bold). Although temperature and sunlight intensity
varied as does in in vivo conditions of cyanobacteria,
all algal cultures were subjected to the same ambient
temperature and light intensity fluctuations.
Algal cultures were analyzed on days one, three,
eight, 10, and 15. Samples were taken from all algal
cultures exposed to their respective wavelength of light
and observed under a light microscope on 40x
magnification. Frequency of heterocyst differentiation
was measured by counting the number of vegetative
cells in between two heterocysts. For each of the four
algal cultures, five to eight measurements were
recorded on each of five days.
Variance among the average numbers of vegetative
cells for all light groups was analyzed using the
ANOVA (analysis of variance) statistic originated by
Fisher (1918).
Results
The average number of vegetative cells between
two heterocysts were as follows: average number of
vegetative cells for the bacteria exposed to white light
= 12, average number of vegetative cells for the
bacteria exposed to red light = 36, average number of
vegetative cells for the bacteria exposed to green light
= 31 and average number of vegetative cells for the
bacteria exposed to blue light = 37. There was a
significant difference between the average number of
vegetative cells seen between two heterocysts in the
13
Saddleback Journal of Biology
Spring 2006
Average number of vegetative cells
between adjacent heterocysts
45
White Light
Red Light
Green Light
Blue Light
40
35
30
25
20
45
Average number of vegetative cells
between adjacent heterocysts
bacteria exposed to white light and red light as well as
the bacteria exposed to white light and blue light (p <
0.05, two-factor with replication ANOVA) (Figure 5).
40
35
30
White Light
Red Light
Green Light
Blue Light
25
20
15
10
5
0
15
Different colors of light
10
Figure 4. The average number of vegetative cells
between two heterocysts in Anabaena sp. strain PCC
7120 exposed to different colors of light (day 10).
5
0
Different colors of light
Average number of vegetative cells
between adjacent heterocysts
45
White Light
Red Light
Green Light
Blue Light
40
35
30
25
20
15
45
Average number of vegetative cells
between adjacent heterocysts
Figure 1. The average number of vegetative cells between
two heterocysts in Anabaena sp. strain PCC 7120 exposed to
different colors of light (day 1).
40
35
White Light
Red Light
Green Light
Blue Light
30
25
20
15
10
5
0
10
Different colors of light
5
0
Different colors of light
Figure 2. The average number of vegetative cells
between two heterocysts in Anabaena sp. strain PCC
7120 exposed to different colors of light (day 3).
Figure 5. The average number of vegetative cells
between adjacent heterocysts in Anabaena sp., exposed
to different colors of light (day 15). There is a
significant difference between white & blue light as
well as white & red light groups. (p<0.05, 2 factor).
Discussion
Average number of vegetative
cells between adjacent
heterocysts
45
40
35
30
White Light
Red Light
Green Light
Blue Light
25
20
15
10
5
0
Different colors of light
Figure 3. The average number of vegetative cells
between two heterocysts in Anabaena sp. strain PCC
7120 exposed to different colors of light (day 8).
The results indicate that the frequency of
heterocyst differentiation in filaments of Anabaena sp.
strain PCC7120 was decreased after exposure to green,
red and blue light for fifteen days (Figure 5). In
Anabaena sp., heterocysts are regularly intercalated
among vegetative cells, and are separated by
approximately 10–20 vegetative cells (Zhang et al.,
2006). In this study, the average number of vegetative
cells between two heterocysts before the start of the
experiment was 12 (Figure 1) and remained unchanged
for the group of Anabaena sp. filaments that were
exposed to white light for 15 days (Figure 5).
However, the average number of vegetative cells
for the red, green, and blue light groups gradually
increased during the 15 day span (Figures 2,3,4,5). A
significant change was seen in the groups of Anabaena
sp. filaments that were exposed to blue and red light
with the group exposed to blue light illustrating the
greatest variation (Figure 5). In contrast, the smallest
14
Saddleback Journal of Biology
Spring 2006
change was seen in the group exposed to green light
(Figure 5). The results seen in the groups exposed to
red and green light are consistent with inhibition of
heterocyst differentiation in the presence of red light
and stimulation of heterocyst formation in the presence
of green light in another heterocyst forming
cyanobacterium Calofbrix sp. strain PCC7601
(Campbell et al., 1993).
One possible explanation for the greatest
frequency of heterocysts in filaments exposed to green
light (excluding the white light group) involves
nitrogenase, an oxygen-sensitive enzyme responsible
for differentiation of heterocysts from vegetative cells
(Zhang et al., 2006). Based on the action spectrum of a
nitrogenous-catalyzed reaction called acetylene
reduction, the highest activity of nitrogenase occurs in
the wavelength range around 560 nm (the visible green
light wavelength range) (Tyagi et al., 1981).
Stimulation of nitrogenase under green light could
account for the observed stimulation of heterocyst
formation.
In addition, heterocyst development requires a
microoxic environment in which nitrogenase can
function. Consequently, Photosystem II, which is
responsible for oxygen production, is absent in
heterocysts (Zhang et al., 2006). Although this is the
case, Photosystem II is still present in vegetative cells
and can still affect the heterocystous cells nearby. One
study of absorption spectra of Anabaena sp. indicates
that light energy can be absorbed by peripheral lightharvesting antenna (PBS) at approximately 515 nm
(invisible blue light region). PBS then transfers the
absorbed light energy to Photosystem II (Ying et al.,
2002). These data indicate that blue light could in fact
stimulate the activity of Photosystem II, resulting in an
overall increase in the amount of oxygen produced. In
turn, this excess amount of oxygen could inhibit the
activity of nitrogenase. Therefore, a decrease in
differentiation of heterocysts under blue light is
expected.
The study of absorption spectra of heterocyst and
vegetative cells in Anabaena sp. also indicates that the
region of the electromagnetic spectrum corresponding
to visible red light correlates to the regions with very
small amount of absorbance (Ying et al., 2002).
Accordingly, when the Anabaena sp. filaments are
exposed exclusively to red light, they are unable to
absorb enough light energy needed for metabolic
activity in different cells. Since the nitrogen fixing cells
are found to have elevated light energy requirements
(Tilzer, 1987), they are at a disadvantage when
exposed to red light.
Vegetative cells and heterocysts have several
structures in common that are involved in
photosynthesis. These structures include photosystem I,
phycobilins, phycocyanins, and allophycocyanins
(Zhang et al., 2006). Paralleling similar structures
responsible for light absorption is similar absorption
spectra. Minor differences in absorption spectra are
due to the absence of Photosystem II, its light
absorbing components and the peripheral lightharvesting antenna (PBS) in heterocysts (Ying et al.,
2002). The absorption spectrum for Anabaena sp. as a
whole consists of several peaks with the major ones at
approximately 430-460 nm and 630-670 nm, which are
the wavelengths that allow maximum yields of
photosynthesis (Ray et al., 1979).
Photosynthesis
directly affects heterocysts since they rely on
vegetative cells as sources of carbon and reductant; in
return, heterocysts supply the surrounding vegetative
cells with fixed nitrogen. Cooperation between the two
functionally distinct cell types is essential to both the
filament growth and heterocyst formation (Zhang et al.,
2006).
A reason why white light contributed to the
differentiation of heterocysts might be because it
includes all wavelengths of the visible spectrum,
including the ranges that contribute to photosynthesis
in vegetative cells. In turn, heterocysts are supplied
with a high amount of energy and fixed carbon needed
for growth. White light also covers the wavelength
range for stimulating the activity of nitrogenase which
is essential for the fixation of nitrogen.
What is intriguing with the significant increase of
vegetative cells in the blue and red light groups is that
these results suggest that differentiation of vegetative
cells into heterocysts has been delayed. In the presence
of fixed nitrogen sources such as ammonia, Anabaena
sp. has been known to delay cell differentiation into
heterocysts. Since fixed nitrogen is already provided to
the algal culture, the need for heterocysts to fix
nitrogen is no longer such a high priority. Although no
source of ammonia was present among the algal
cultures in this experiment, a similar process of
delaying cell differentiation might be occurring here
with the exposure to blue and red light. The algal
cultures favored the preservation of vegetative cells.
Since the main difference between vegetative cells and
heterocysts is that vegetative cells perform oxygenated
photosynthesis, the algal cultures exposed to blue and
red lights may have been attempting to balance the suboptimal light energy absorbance with more vegetative
cells to perform photosynthesis.
Acknowledgements
The authors thank Science Kit & Boreal Laboratories
for providing the live Anabaena sp. strain PCC7120
and Bristol’s Solution (H.C. Bold modified) used in
this study. The authors also thank professor Steve Teh
for his helpful comments and graciously providing the
materials used in this study.
15
Saddleback Journal of Biology
Spring 2006
Literature Cited
Bergman B., Gallon JR., Rai AN., Stal LJ. 1997. N2
fixation by non-heterocystous cyanobacteria. FEMS
Microbiology Reviews. 19(3):139-85.
Bold HC. 1949. The morphology of Chlamydomonas
chlamydogma Sp. Nov. Bull. Torrey Botan. Club.
76:101-108.
Campbell D., Houmard J., de Marsac NT. 1993.
Electron transport regulates cellular differentiation in
the filamentous cyanobacterium Calothrix. The Plant
Cell. 5:451-63.
Fay P., Cox RM. 1967. Oxygen inhibition of nitrogen
fixation in cell-free preparations of blue-green algae.
Biochim Biophys Acta. 143(3):562-9.
Fisher R. 1918. The correlation between relatives on
the supposition of Mendelian inheritance. Trans. Roy.
Soc. Edinb. 52:399-433.
Laurent S., Chen H., Bédu S., Ziarelli F., Peng L.,
Zhang CC. 2005. Nonmetabolizable analogue of 2oxoglutarate elicits heterocyst differentiation under
repressive conditions in Anabaena sp. strain PCC 7120.
Proc Natl Acad Sci USA. 102: 9907–9912.
Li JH., Laurent S., Konde V., Bédu S., Zhang CC.
2003. An increase in the level of 2-oxoglutarate
promotes
heterocyst
development
in
the
cyanobacterium Anabaena sp. strain PCC7120.
Microbiology. 149:3257-3263.
Muro-Pastor MI., Reyes JC., and Florencio FJ. 2001.
Cyanobacteria perceive nitrogen status by sensing
intracellular α-ketoglutarate levels. J Biol Chem. 276:
38320–38328.
Ray TB., Mayne BC., Toia Jr. RE., Peters GA. 1979.
Photosynthetic characterization of the association and
individual partners. Plant Physiol. 64:719-5.
Sakr S., Jeanjean R., Zhang CC., Arcondeguy T. 2006.
Inhibition of cell division suppresses heterocyst
development in Anabaena sp. strain PCC7120. J.
Bacteriol. 188(4):1396-404.
Tilzer MM. 1987. Light-dependence of photosynthesis
and growth in cyanobacteria: implications for their
dominance in eutrophic lakes. New Zealand Journal of
Marine and Freshwater Research. 21:401-12.
Torrecilla I., Leganés F., Bonilla I., Fernández-Piñas F.
2004. A calcium signal is involved in heterocyst
differentiation in the cyanobacterium Anabaena sp.
PCC7120. Microbiology. 150:3731-9.
Tyagi VVS., Ray TB., Mayne BC., Peters GA. 1981.
Phycobiliproteins in the action spectrum for
nitrogenase-catalyzed acetylene reduction. Plant
Physiol. 68:1479-84.
Wolk CP., Ernst A., Elhai J. 1994. Heterocyst
metabolism and development. The Molecular Biology
of Cyanobacteria. Bryant, DA. (ed.). Dordrecht, the
Netherlands: Kluwer Academic Publishers, pp. 769823.
Ying L., Huang X., Huang B., Xie J., Zhao J., Zhao X.
2002. Fluorescence emission and absorption spectra of
single Anabaena sp. strain PCC7120 cells.
Photochemistry and Photobiology. 76(3):310-3.
Zhang CC., Laurent S., Sakr S., Peng L., Bédu S. 2006.
Heterocyst differentiation and pattern formation in
cyanobacteria: a chorus of signals. Molecular
Microbiology. 59(2):367-75.
Zhao Y., Shi Y., Zhao W., Huang X., Wang D., Brown
N., Brand J., Zhao J. 2005. CcbP, a calcium-binding
protein from Anabaena sp. PCC7120, provides
evidence that calcium ions regulate heterocyst
differentiation. Proc Natl Acad Sci USA. 102:5744-8.
16
Saddleback Journal of Biology
Spring 2006
The Effect of Salt Concentration on Garden Bean (Phaseolus vulgaris) Germination
Vanessa Acosta, Shallom Han and Jamie Stevens
Department of Biological Sciences
Saddleback College
Mission Viejo, CA 92692
This experiment measured the difference in germination of garden beans (Phaseolus
vulgaris L.) that were placed in salt solutions varying from 0-500 mOSM. The rate of
germination of the Phaseolus vulgaris L. was noted by placing them in their assigned
solutions, and counting every two days how many Phaseolus vulgaris L. germinated during
a two week period. This project was undertaken to find the threshold for the germination
of Phaseolus vulgaris L. at different salinities to benefit gardeners, farmers, and botanists.
It was hypothesized that the Phaseolus vulgaris L. in a solution greater than 300 mOSM
would not germinate nearly as well as those in 0-200 mOSM solution. Results indicated
that at 200 mOSM and above, the Phaseolus vulgaris L. did not germinate as quickly and
many did not even germinate at all. In contrast, the 0 mOSM and 100 mOSM had 22
Phaseolus vulgaris L. germinate by day two. An ANOVA test value of p=0.001 confirmed
that our results are highly significant of our null hypothesis. This revealed that the
Phaseolus vulgaris L. is affected by the presence of salt; however a small amount of salt
does not inhibit germination either.
Introduction
Soil salinity is a very important issue worldwide
as it can inhibit crop production. Some crops are
tolerant of the presence of salt, however most are not,
such as the common bean (Peel, et al. 2004). Poor
crop production can have a negative effect on many
people, from those who cultivate it, since they will
lose out on money, to those who use the crops for
personal benefit, such as food. Farmers and growers
have asked for better information regarding the salt
tolerance of different species of crops (Steppuhn, et
al. 2001). There are already germinating compounds,
such as kinetin and ethylene, which help alleviate the
effect of salinity on halophytes, which are plants that
live in saline environments (Khan, et al. 2004).
Something that would work similar to this on plants
that do not live in salty areas would be a significant
discovery and extremely helpful to society, especially
the farmers. Jensen et al. (2005) say that artificial
selection must be done at several stages of plant
growth in order to develop more salt tolerant plants.
There are many different species of beans,
which are consumed in many ways worldwide and, as
stated above, most are not tolerant of a saline habitat.
Beans come in different colors, grow differently, as
they climb or stay low on the soil, and come in
different forms, snapped or shelled beans (Cook
1993). Phaseolus vulgaris L. is popular species
because they do not take too long to germinate and
develop however it is not tolerant of salt. Since this
is the case, the objective of the present study was to
learn where there is a cut-off salinity point for the
Phaseolus vulgaris L. where they will not further
germinate. It was hypothesized that at a 300mOSM
salt solution, there would be an extreme drop in
germinating Phaseolus vulgaris L., as the amount of
salt at that level would be too much for the Phaseolus
vulgaris L. to withstand.
Materials and Methods
In March 2006, garden Phaseolus vulgaris L.
(Phaseolus vulgaris L.) were purchased at a Lowe’s
store in Rancho Santa Margarita, California.
Furthermore, thirty Petri dishes used for this study
were obtained from the Saddleback College
Department of Biology. Walnut Grove Market
Distilled Water, non-iodized salt, and a bag of
standard cotton balls were also purchased from a
grocery store.
Two cotton balls were spread apart and placed
as a lining in each Petri dish to serve as soil for the
Phaseolus vulgaris L.. Five Phaseolus vulgaris L.
were then placed in each of the thirty Petri dishes in
which they were evenly spaced apart from one
another. Five groups of five dishes received 100,
200, 300, 400, and 500 mOSM salt solutions, which
would serve as the source of nutrients for the
Phaseolus vulgaris L. The last five dishes would be
17
Saddleback Journal of Biology
Spring 2006
Results
The number of Phaseolus vulgaris L. that
germinated over the two week period depended on
the varying salinities. Twenty-four of the 25
Phaseolus vulgaris L. in the 100 mOSM germinated
after four days. The Phaseolus vulgaris L. in the plain
distilled water germinated a maximum of 22 beans
and this all occurred by the second day. The 200
mOSM set of Phaseolus vulgaris L. ended up
germinating 21 beans, however it took eight days for
this to unfold. Although the 300 mOSM solution
germinated 22 seeds, it took ten days to achieve this
feat. The 400 mOSM and 500 mOSM salt solutions
were the most stressful on the Phaseolus vulgaris L.,
which resulted in the lowest amount of Phaseolus
vulgaris L. being germinated. It took ten days for 18
seeds in the 400 mOSM and 15 seeds in the 500
mOSM to germinate (Figure 1). An ANOVA test
was performed at 14:12 on 19-APR-2006 to
determine the statistical significance of our data.
According to the analysis of our results by the
ANOVA test, p=0.001, which is indicative of our
results being highly significant.
Discussion
Phaseolus vulgaris L. which were guaranteed to
germinate, were purchased in order to view their
overall potential growth. As one can see in Figure 1,
the 0 mOSM and 100 mOSM solutions were the
optimal conditions for Phaseolus vulgaris L.
germination. The two solutions germinated the most
amount of Phaseolus vulgaris L. in the shortest
amount of time, but the 100 mOSM was the best
overall since
25
Number of Seeds
Germinated
watered with plain distilled water. To concoct the
various salt solutions, calculations were completed to
discover the quantity of salt that had to be placed in
one-half liter of water. The 100 mOSM solution
received 1.461g of salt, the 200 mOSM solution
received 2.922g, the 300 mOSM solution had 4.383g,
the 400 mOSM solution 5.844g and the 500 mOSM
received 7.305g of salt. After this was done, the salt
was weighed out on a scale and once the right
amount was obtained, the salt was placed in one-half
liter of the distilled water and stirred until thoroughly
mixed. Groups of five Petri dishes of Phaseolus
vulgaris L. were then each designated to be watered
with pure distilled water or the 100, 200, 300, 400, or
500 milliosmolar salt solutions. The Phaseolus
vulgaris L. were then watered with their assigned
water or solution similar to how they would be
watered if they were in true soil, moist, but not
saturated. All thirty dishes were then lined up and
placed in an area where they would receive plenty of
sunlight during the daytime hours. Every two days
for two weeks the beans were checked on and the
amount of beans that germinated in each saline
environment was written down. The beans were also
watered with their assigned water as needed.
20
0 mOSM
15
100 mOSM
10
200 mOSM
5
300 mOSM
0
400 mOSM
0 2 4 6 8 10121416
500 mOSM
Day of Study
Figure 1. The 2-4 D and the NAA groups both had a greater
tomato mass than the Water group (p =0. 015). There was no
statistical difference between NAA and 2-4D
it yielded the most seeds germinated. An explanation
of this is that the 100 mOSM is the target amount of
salinity providing enough ions for growth. The 200
mOSM through 500 mOSM solutions germinated
less Phaseolus vulgaris L. per Petri dish at a more
gradual rate of time. The 200 mOSM through 500
mOSM were probably too high of a concentration for
the Phaseolus vulgaris L. to grow. It is also
interesting to note that although the 200-500 mOSM
germinated they seized to grow past 20 millimeter in
length. These results are economically important to
farmers worldwide, because it gives them the optimal
solution for harvesting the most Phaseolus vulgaris
L. for maximizing their profit. However, our data
fails to support the hypothesis that 300 mOSM would
be the point in which the Phaseolus vulgaris L.
germinate. The results show that 200 mOSM is the
point in which the bean germination dropped
drastically. According to Bayuelo-Jimenez (2002),
the presence of salinity diminishes crop formation as
it impairs seed germination, reduces nodule
formation, and hinders development. This proved to
be true in our study since starting from 200 mOSM
salinity, the growth of Phaseolus vulgaris L. was
inhibited. As the number of days increased, the
number of Phaseolus vulgaris L. that germinated also
increased respectively, except for the 0mOSM, which
germinated all of its potential germinating Phaseolus
vulgaris L. by the second day. Although the ambient
temperature in the room changed in which the
experiment was conducted, all of the beans were
susceptible to the same conditions. The beans were
all placed close enough to each other that at any
18
Saddleback Journal of Biology
Spring 2006
given point in time they would be under the same
conditions. Hopefully these results will give farmers
some of the answers that they were looking for, but
were unable to obtain in the past.
Literature Cited
Bayuelo-Jimenez J, Craig R, Lynch J. 2002. Salinity
Tolerance
of
(Phaseolus)
Species
During
Germination and Early Seeding Growth. Crop
Science, 42(5): 1584-1595.
Cook, Adrienne. 1993. Better Beans; Fast Growing,
Soil Enhancing - And Now Stringless. The
Washington Post, p. T18
Jenson K, peel M, Waldron B, Horton W, Asay K.
2005. Persistence After Three Cycles of Selection in
NewHy RS-Wheatgrass. Crop Science, 45(5): 17171721.
Khan M, Gul B, Weber D. 2004. Action of Plant
Growth Regulators and Salinity on Seed Germination
of (Ceratoides lanata). Canadian Journal of Botany,
82(1): 37-43.
Peel M, Waldron B, Jensen K, Chatterton N, et al.
2004. Screening for Salinity Tolerance in Alfalfa: A
Repeatable Method. Crop Science, 44(6): 2049-2054.
Stepphun H, Volkmar K, Miller P. 2001. Comparing
Canola, Field Pea, Dry Bean, and Durum Wheat
Crops Grown in Saline Media. Crop Science, 41(1):
1827-183
The Effect of Caffeine on Exercise and Heart Rate in Homo sapiens
R. Michael Kolb and Ryan Matthew Whyte
Department of Biological Science
Saddleback College
Mission Viejo, California USA
The effects that caffeine would have on exercise and heart rate were investigated. Trial
one consisted of eight students from Saddleback College running on a treadmill for
duration of 10 minutes at 5 miles per hour. In trial two the same eight participants were
asked to consume a 200 mg caffeine pill and run 10 minutes at 5 miles per hour. The
hypothesis was that caffeine would lower the heart rate of each participant significantly
resulting in an improved performance during exercise (taking longer to fatigue). Results
showed that the participants had a lower heart rate after exercise from taking the caffeine
pill. Participants ranged between 18 and 35 years of age. By using a paired, one-tailed ttest the collected data showed there was a significant difference between the trial run
without caffeine and the trail run with caffeine, by having a p-value (p<0.05) of 3.3 x 10-5.
A possible reason for this event to have occurred could be because caffeine by some is
considered ergogenic which would result in a decrease in heart rate and thus an increase in
exercise performance.
Introduction
Caffeine is a bitter white alkaloid, C8H10N4O2,
often derived from coffee or tea and is used in
medicine chiefly as a stimulant. Structurally related
to uric acid, caffeine (1, 3, 7-trimethylxanthine) is
one of three methylated xanthine alkaloid derivatives
that are present in many plant species throughout the
world. They have been used more commonly used in
sports today to increase performance during exercise
and competition.
Caffeine has been scientifically shown to directly
have a stimulating effect on the central nervous
system; it increases the excitation of the brain and
spinal cord, the cardiac output and rate of
metabolism. In many athletic competitions today,
stimulants, such as amphetamines, cocaine, ephedrine
and caffeine, are illegal. Azpiazu, Manchester and
others discussed how caffeine is distributed
throughout all body water including the brain. The
highest concentrations are found in skeletal muscles.
19
Saddleback Journal of Biology
Spring 2006
200
180
160
140
120
HR/min
Since caffeine concentrations are the highest in
muscle tissue, this may be the reason for its
ergogenic actions on athletes.
Along with the positive performance that comes
with taking caffeine before or during intense,
strenuous activity it also has its negative side effects.
These include a loss of appetite, periods of insomnia
(lack of sleep), reduction of fatigue later resulting in
exhaustion, psychosis (hallucinations), trembling,
restlessness, agitation, tenseness, hypertension (high
blood pressure), palpations and heart rhythm
disorders along with addiction.
The purpose of the present experiment was to
determine the effects of caffeine on exercise and
heart rate. It was hypothesized that with the use of
caffeine and exercise together, the final heart rate
would be lower than the final heart rate without the
caffeine, hence caffeine would help in improving the
ability to do exercise.
100
80
60
Without caffeine
With caffeine
40
20
0
1
2
3
4
5
6
7
8
Participants
Figure 1. Final heart rates after exercise using caffeine
vs. no use of caffeine.
Figure 2 shows the actual difference in the final
heart rates. (Final heart rate after exercise without
caffeine subtracted from the final heart rate after
exercise with caffeine).
0
1
Materials and Methods
Results
The 8 participants that were run on the Nordic
Track Treadmill all showed similar results which
provided evidence to support the hypothesis
correctly. Every participant experienced a decrease
in their final heart rate between trial one (the control
group) and trial two (caffeine group). Figure 1 shows
a comparison of the two groups and their final heart
rate for each of the two trials.
3
4
5
6
7
8
-10
HR/min
Eight students from Saddleback College
volunteered to participate. Students ranged between
18 and 35 years of age. Consumption of any food
and liquids within the past 24 hours was recorded.
Participants were asked not to consume any caffeine
within the 24 hour time span. All participants ran on
a Nordic Track Treadmill for ten minutes at five
miles per hour. Using a Polar E600 heart rate monitor
the heart rate was recorded.
The following week the same eight participants
were each given 200 mg of NoDoz brand caffeine
pills. The caffeine pills were consumed
approximately 45 minutes before exercise began.
Participants were then asked to run again in the same
fashion they had run the week before. Consumption
of food and liquids within the past 24 hours was
again recorded. Participants were also again asked
not to consume any caffeine within the 24 hour time
period. Heart rate for each participant was recorded
using the Polar E600 heart rate monitor. The
difference in heart rate of the two trials was
calculated for results.
2
-5
-15
-20
Difference in
final heart rates
-25
-30
Participants
Figure 2. Effect of Caffeine on exercise heart rate,
difference in final heart rate of two trials. 4 male and 4
female participants from Saddleback College.
The hypothesis deemed correct by participants
experiencing a decrease in heart rate and a reported
increase in exercise performance. By using a paired,
one-tailed t-test with a p-value (p<0.05) of 3.3 x 10-5
a significant difference was shown. There was no
previously recorded evidence (when each participant
was asked to write down what they had to eat or
drink within the last 24 hours) of any previously
consumed food or liquids that would alter these
results.
Discussion
Caffeine is the most inexpensive and readily
available drug known to man. Because of its
widespread use it has been given a bad rap and
labeled addictive, which it very may well be. There
are people that if they go without their usual cup of
coffee, they experience headaches and lack of
concentration. Then on the other hand there are
20
Saddleback Journal of Biology
Spring 2006
people who view caffeine as a helpful stimulant that
increases the individual’s concentration and
awareness as well as many other physical traits.
In the present experiment caffeine did affect
exercise and the heart rate of each participant
involved. Participants experienced a lower heart rate
after the consumption of the caffeine pills and also
reported feeling an increase in energy improving
exercise performance. Jack Hartley from the Health
Psychology Department at Vanderbilt University says
that caffeine stimulates the Central Nervous System
at high levels, like the medulla and cortex, and even
has the ability to reach the spinal cord in larger doses.
The effect of caffeine in the cortex is a clearer
thought process and also can rid the body of fatigue.
This gives people a greater ability of concentration
for 1-3 hours. For athletes competing in sports where
quick thinking and rapid reactions are necessary,
caffeine can provide a huge edge. Aside from the
physical benefits caffeine may provide a mental edge,
which can be extremely important in competitive
sports nowadays.
There may be several reasons why caffeine had an
affect on each of the participants. One reason is that
caffeine has been scientifically proven to directly
have a stimulating effect on the central nervous
system; increasing the excitability of the brain and
spinal cord, the cardiac output and rate of
metabolism. Davis found this to be true when testing
with rats. Studies show that in the first fifteen
minutes of exercise caffeine has the potential to
reduce the loss of glycogen by fifty percent. When
this happens, the saved glycogen can be used for the
remainder of the workout where normally it would be
entirely depleted. There is a general agreement that
caffeine forces the use of fatty acids for energy first
rather than using muscle glycogen, there is no real
evidence to how this is done however.
Despite positive and consistent results, further
research may be required to determine accuracy and
true effect of caffeine. A larger control and test
group is needed, as well as a diverse range of people
from different ethnicities and age groups. Sideeffects of caffeine and its long term use were not
studied nor specifically observed.
Davis M. J. (2003). Central nervous system effects of
caffeine and adenosine on fatigue. American Journal
of Physiology, 28, 399-404.
Falk B., Burstein R., Ashkenazi I., Spilberg O., Alter
J., Zylber-Katz E., Rubinstein A., Bashan N., and
Shapiro Y. (1989). The effect of caffeine ingestion on
physical performance after prolonged exercise.
European Journal of Applied Physiology. 59, 168–
173.
Graham TE. (2001). Caffeine and exercise:
metabolism, endurance, and performance. Sports
Medicine, 31, 785–807.
Hartley, J. (2000) Caffeine and sports performance.
World Wide Web, Vanderbilt University Psychology
Department.
MacIntosh BR, Wright BM. (1995). Caffeine
ingestion and performance of a 1,500-meter swim.
Canadian Journal of Applied Physiology, 20, 168–
177.
Sasaki H., Takaoka I., and Ishiko T. (1987). Effects
of sucrose or caffeine ingestion on running
performance and biochemical responses to endurance
running. International Journal of Sports Medicine, 8,
203–207.
Spiller, Gene A. (1998). Caffeine. CRC Press, 233250.
Literature Cited
Azpiazu I., Manchester J., Skurat AV, Roach PJ, and
Lawrence JC Jr. (2000). Control of glycogen
synthesis is shared between glucose transport and
glycogen synthase in skeletal muscle fibers.
American Journal of Physiology, 278, E234–E243.
21
Saddleback Journal of Biology
Spring 2006
The Effect of Carbohydrate Loading on Oxygen Consumption in White Mice
(Mus musculus)
Karl Hodel and Reid Sneddon
Department of Biological Sciences
Saddleback College
Mission Viejo, California USA
Increasing amounts of carbohydrates consumed prior to exercise has been shown to
increase athletic performance. This is commonly known as “carbo-loading”. In this study
the impact of a diet, rich in carbohydrates, on oxygen (O2) consumption (mL/g) in exercised
White Mice (Mus musculus) was tested. The oxygen consumptions of the group of mice
that were “carbo-loaded” were compared to that of a second group of mice that were fed a
normal rodent diet. During the experiment, the mean post-exercise oxygen consumption of
each group (N=5) was calculated. The “carbo-loaded” mice had a mean O2 consumption of
0.1 mL/g upon the completion of five minutes of exercise and the normally fed mice had a
mean oxygen consumption of 0.1 mL/g. As a result, there was no significant difference
(p=1.0) between the post-exercise oxygen consumption of the two groups of mice.
Introduction
It has long been believed that a diet rich in
carbohydrates is essential for maximal athletic
performance.
The process of consuming large
quantities of foods with high carbohydrate content
before and athletic event is known as “carboloading”. Glycogen is the storage form of glucose
molecules in animals. Glycogen functions as an
immediate source of glucose for muscle cells (Rauch,
1995). It has been shown that muscle glycogen
content will increase as result of this “carbo-loading”.
In addition, a diet of high carbohydrate content,
consumed two to three days before an athletic event,
has been demonstrated to increase performance and
output (Halkey, 1997).
Dr. Jonas Bergström, who is regarded as the father
of “carbo-loading”, discovered that if athletes were
placed on a very-high-fat (90 percent), low-carb diet,
their exercise performance was markedly impaired
compared to their performance when they had eaten a
high-carb diet before exercise (Carrier, 1984). This
practice of supplementing normal diets with
carbohydrates is utilized by all types of athletes, but
is especially helpful during endurance exercise. A
study of eight endurance cyclists was performed to
study the effects of “carbo-loading”. The cyclist’s
diets, in this study, were supplemented by
carbohydrates in the form of potato starch for three
days prior to testing (Rauch, 1995). This showed an
increase in pre-exercise muscle glycogen levels,
individual power output, and overall distance covered
in one hour of cycling. In a similar study it was
shown that eight trained endurance athletes increase
muscle glycogen levels by 41% as a result of a fourday “carbo-loading” phase (Tarnopolsky, 1995).
It has firmly been established in numerous studies
that a diet rich in carbohydrates, consumed before
exercise, will increase performance and muscular
output. The objective of this study is to determine if
“carbo-loading” will benefit the subject in the area of,
athletic performance as a measure of post-exercise
oxygen (O2) consumption. It was predicted that the
post-exercise oxygen consumption of white mice
(Mus musculus) fed a supplemented diet high in
carbohydrate content (in the form of pasta), would be
significantly less than that of white mice that were
not fed the supplemented carbohydrate diet.
Materials and Methods
Ten white mice (Mus musculus) were obtained
from Prehistoric Pets (Fountain Valley, CA). The
mice were separated into two groups (n=5), each
consisting of all female specimens to prevent fighting
and breeding. Each mouse was weighed and labeled
with a number on the tail and separated into their
respective experimental and controlled cages. Prior
to initial data recording, each group was fed an
identical diet of Nutriphase Rodent Formula
(Phoenix, AZ).
During the initial data recording, the oxygen
consumption (mL) of each mouse was taken at rest
using a FoxBox Field Gas Analysis System (Sable
Systems Las Vegas, NV) for five minutes. The
specimen was then run on a treadmill for five minutes
at a speed of .174 m/s. Upon completion of the five
minutes of exercise, the mouse was transferred to the
22
Saddleback Journal of Biology
Spring 2006
FoxBox and the oxygen consumption (mL) was
recorded for an additional five minutes.
After initial data recording, the experimental
group was fed a supplemental diet of a pasta, rich in
carbohydrates in addition to their regular diet, while
the control group remained on the initial pre-data
recording diet. The experimental group was kept on
the supplemental diet for 48 hours until final run
recordings were taken. During the 48 hours of
“carbo-loading” phase, each specimen in the
experimental group consumed 4.71 g of
carbohydrates from their supplemental food source.
The post supplemental diet oxygen consumption
(mL) recordings were taken in the same manner in
which the initial oxygen consumptions (mL) were
obtained.
Results
During exercise muscles are working harder then
at rest and will therefore be in need of more oxygen.
Regardless of being “carbo-loaded” each group of
mice showed an increase in oxygen consumption
after completion of exercise (Figure 1 and
Figure 2).
“Carbo-loading” white mice did not significantly
decrease (p=1.0) post-exercise oxygen consumption
when compared with post-exercise oxygen
consumption of regularly dieted mice (Figure 3).
0.12
0.1
0.08
1st Resting
1st Run
0.06
2nd Resting
0.04
2nd Run
0.02
0
Run Number
Figure 1. Mean Oxygen (O2) consumption
(mL/g) for regularly dieted white mice (Mus
musculus) before and after exercise
0.12
0.1
0.08
1st Resting
0.06
1st Run
2nd Resting
0.04
2nd Run
0.02
0.12
0.1
2nd Control Run
0.08
2nd Carb Run
0.06
0.04
0.02
0
Run Number
Figure 3. Mean post-exercise oxygen (O2)
consumption of "carbo-loaded" white mice (Mus
musculus) and normally fed white mice
Discussion
Both groups of mice, regardless of being fed a
regular or carbohydrate diet, showed increases in
oxygen consumption (mL/g) after exercise when
compared to their resting oxygen consumptions
(Figure 1). However, there was no significant
difference between the two groups, when the postexercise oxygen consumptions of the carbohydrate
and regular groups were compared (Figure 3). In this
study it was determined that “carbo-loading” and
post-exercise oxygen consumption are not directly
related. Although it has been shown that “carboloading” will increase athletic performance (Rauch
1995) the opposite effects were seen in this study,
assuming oxygen consumption can be considered a
measure of athletic performance.
Most studies relating to the subject of “carboloading” had the subjects exercised for a time that
was considered “endurance level”. If post-exercise
oxygen consumption is in fact coupled with “carboloading” a longer duration of exercise could result in
a significantly lowered post-exercise oxygen
consumption (mL) in the experimental group.
It should be noted, however, that while the data is
inconsistent with the hypothesis, an increase in
running performance was visible in the carbohydrate
group. This group ran at the very front of the
treadmill while the control group ran near the middle
and back. In addition, upon return to the subject’s
cage, the group that was “carbo-loaded” appeared to
have more energy than the control group. This visual
observation of increased performance is consistent
with the knowledge that “carbo-loading” does
increase athletic performance (Rauch 1995, Carrier
1998).
0
Run Number
1
Acknowledgements
Figure 2. Mean Oxygen (O2) consumption (mL/g)
for supplementary carbohydrate dieted white mice
Mus musculus before and after exercise
We thank Dr. Tony Huntley and Professor Steve Teh
for aiding in the use of the FoxBox oxygen analysis
system.
23
Saddleback Journal of Biology
Spring 2006
Literature Cited
Carrier D. 1984. The Energetic Paradox of Human
Running and Hominid Evolution. Current
Anthropology. 25(4): 483-496.
Halkey JA, Schabort EJ, Noakes TD, Dennis SC.
1997. Carbohydrate-loading and exercise
performance. Sports Med. 24(2): 73-81.
Rauch LH, et. al. 1995. The effects of carbohydrate
loading on muscle glycogen content and cycling
performance. International Journal of Sports
Nutrition. 5(1): 25-36.
Tarnopolsky MA, Atkinson SA. 1995. Carbohydrate
loading and metabolism during exercise in men and
women. Journal of Applied Physiology. 78(4): 13601368.
The Effects of Lactic Acid Injections on the Tail Contraction Speed of Freshwater
Crawfish, Procambarus clarkii
Matthew Cosley and Matthew Michaelian
Department of Biological Sciences
Saddleback College
Mission Viejo, CA 92692
In this experiment, tail contraction speeds were measured in nine freshwater crawfish,
Procambarus clarkii. The crayfish were injected with a 300 mOSM freshwater crustacean
saline solution, and a 300 mOSM saline lactic acid solution. Tail contractions were then
induced using electric stimulation and speeds were recorded with a video camera. The
mean value, in seconds, for the tail contraction speed in P. clarkii with no injections was
0.040±0.001 S.E., in P. clarkii injected with normal saline was 0.037±0.001 S.E., and
injected with lactic acid was 0.045±0.001 S.E. No significance (ANOVA test) was seen
between the no injection and normal saline groups. Tail contraction speed times were
significantly slower (ANOVA test) in the lactate group compared to the saline and no
injection groups.
Introduction
As an ectothermic species, crustaceans do not
produce enough metabolic heat to keep themselves
warm; instead they use environmental energy or
behavioral adaptations to regulate their body heat.
Ectothermy also appears to place limits on an animals
ability to utilize aerobic metabolism to support
rigorous activity (Wagner et al., 1999). Because of
these restrictions, ectotherms must use anaerobic
ways to produce ATP in the muscles to run
locomotive processes. Therefore, with the lack in
oxygen in the glycolysis cycle, we see both a
disappearance of glycogen and an equal amount of
build-up of lactate in muscular regions as a
metabolism end product (Vonk, 1960). With the
build-up of lactate in the muscle, a lower pH inhibits
enzymes to work effectively. Lactate occurring in
muscle regions causes fatigue and pain resulting in a
reduced amount of locomotive movement.
Meyerhof, Lohman and Boyland worked to prove
that the end point of carbohydrate metabolism was
the same in both vertebrates and invertebrates (Vonk,
1960). In mammals, lactate produced during activity
is primarily oxidized in muscle and is removed
relatively quickly during recovery (Donovan and
Gleeson, 2001). Ectotherms lack the ability to
oxidize the lactate in their muscles. Laboratory
research conducted at Saddleback College shows that
with injections of lactic acid in the muscle regions,
there was a significant decrease in time to exhaustion
in house geckoes, Hemidactylus frenatus (Tran and
De Leon, 2004). There has been no research found
on the relationship between lactic acid injections and
tail contraction speeds in crustaceans. The goal of
this study is to visualize the relationship between
lactic acid injections and tail contraction speeds in
Procambarus clarkii. The anticipated result is that
there will be a significant decrease in Procambarus
24
Saddleback Journal of Biology
Spring 2006
Materials and Methods
Animal Care
Nine crawfish (P. clarkii, average weight 27.27g
± 1.7 S.E.) were purchased online from the Louisiana
Crawfish Company in Natchitoches, Louisiana
(www.lacrawfish.com). The crawfish were split up
and kept in two separate glass aquariums: one 20
gallon and 25 gallon. Their chelipeds were tied shut
with rubber bands to avoid territorial violence. The
aquariums were filled with about three inches of dechlorinated water which was changed three times a
week. An air-pump was put in each tank to keep the
water oxygenated and the crawfish were provided
with multiple PVC pipes for shelter.
Experimental Protocol
Each crawfish was tied down with shoelace on
the cephelothorax to an eight inch section of 2x4
piece of wood. The crawfish were then subjected to
one of the three treatment protocols, and allowed to
rest for five minutes. Tail contractions were induced
using a Narco Bio-Systems physiograph projector
model type PMP-4B stimulator. Stimulations were
administered on the ventral side directly to the
exoskeleton at the base of the tail muscle using a
single shock of 30 volts at a frequency of two
milliseconds. Each crawfish was stimulated three
times, once every 20 seconds, during each protocol.
The speed of the contraction was recorded using a
Sony Mini DV handycam (Model No: DCR-TRV27).
Data were analyzed by counting frames using
Pinnacle Studios 9.1, which were converted to
seconds.
Treatment Protocols
The crawfish were subjected to three different
treatment protocols on three separate days. On the
first day, the crawfish were given no injection. On
the second day, they were injected with 1cc of
freshwater crustacean normal saline. On the third
day they were injected with 0.5cc of 300 mOSM
saline lactic acid solution. Injections were made into
the ventral side of the cephalothorax in between the
fourth and fifth walking legs with a 21 gauge Becton
Dickinson & CO. syringe needle.
Results
Tail contraction speed
The average tail contraction speed was calculated
for P. clarkii with no injection, normal crustacean
saline injection and lactic acid injection as shown in
Figure 1. The mean value for the tail contraction
speed, in seconds, for P. clarkii with no injections
was 0.040±0.001 S.E., in P. clarkii injected with
normal saline was 0.037±0.001 S.E., and injected
with lactic acid was 0.045±0.001 S.E. Results among
the three injection groups were compared with
repeated-measures analysis of variance (ANOVA)
followed by a paired post-hoc test. No significance
(ANOVA) was seen between the no injection and
normal saline groups. Tail contraction speed times
were significantly slower (ANOVA) in the lactic acid
group compared to the saline and no injection groups.
0.05
0.045
0.04
0.035
Time (seconds)
clarkii tail contraction speed when injected with
lactic acid compared to no injection.
0.03
No injections
0.025
Saline
0.02
Lactic Acid
0.015
0.01
0.005
0
Treatment1 Protocol
Figure 1. The average tail contraction speed
calculated for nine Procambarus clarkii with no
injection, normal crustacean saline injection and
lactic acid injection. Tail contraction speed times
were significantly slower in the lactic acid group
compared to the saline and no injection groups
(p<0.05, ANOVA test).
Discussion
It was found that tail contraction speeds were
significantly slower in P. clarkii when injected with
lactic acid compared to speeds with no injection. It
was known before this experiment that lactic acid
build up in ectotherms resulted in an exhausting
effect (Tran and De Leon, 2004). Therefore, it was
expected that there would be a negative effect of a
lactic acid injection on the tail contraction speeds.
Our results agreed with this hypothesis.
This experiment indicates that raised lactic acid
levels have a negative effect on tail contraction
speeds in P. clarkii. One explanation why muscle
does not work as well with raised levels of lactic
acid, is that it lowers pH in the muscle (Naylor et al.,
1984). Normal pH levels in muscle are around 7.0
and can be lowered to 6.4 after exercise (Sahlin et al.,
1978). With this lower pH, enzymes are outside their
optimal pH and do not work affectively. The systems
controlling muscle contractions will not work
properly resulting in slower muscle contraction
25
Saddleback Journal of Biology
Spring 2006
speeds. No related resources were found to explain
why pH effects muscle contraction speed.
Further studies can be made to observe effects of
lactic acid on exhaustion times and or escape speeds
in natural habitats in P. clarkii.
Literature Cited
Donovan ER and Gleeson TT. 2001. Evidence for
Facilitated Lactate Uptake in Lizard Skeletal Muscle.
The Journal of Experimental Biology V204, P40994106.
Naylor JM, Kronfeld DS, Freeman DE and
Richardson. D. Hepatic and extrahepatic lactate
metabolism in sheep: effects of lactate loading and
pH. American Journal of Physiology- Endocrinology
and Metabolism, V247, I6, P747-E755
Sahlin K, Alvestrand A, Brandt R and Hultman E.
1978. Intracellular pH and bicarbonate concentration
in human muscle during recovery from exercise.
Journal of Applied Physiology, V45, I3, P474-480.
Tran G and De Leon E. 2004. Premature postexercise exhaustion following lactic acid injection in
the House Gecko, Hemidactylus frenatus. Saddleback
Journal of Biology Vol 2:1-6.
Vonk HJ. 1960. The Physiology of Crustacea:
Digestion and Metabolism. 291-310. Academic
Press. New York, London.
Wagner EL, Scholnick DA and Gleeson TT. 1999.
The Roles of Acidosis and Lactate in the Behavioral
Hypothermia of Exhausted Lizards. The Journal of
Experimental Biology V202, P325-331.
The Effects of a Carbohydrate-Electrolyte Solution on Performance in Endurance Athletes
Kartik Boddupalli and Phat Trang
Department of Biological Sciences
Saddleback College
Mission Viejo, CA 92692 - USA
Adequate replenishment of muscle glycogen with carbohydrates is often necessary
during long periods of endurance demanding activity. A study was conducted based on the
hypothesis that a carbohydrate-electrolyte drink containing 6% sugars (brand name
Gatorade®) would significantly increase athletic endurance during an 8 km biking activity
on a stationary bike. Fifteen male participants were chosen, and were required to perform
two different trials (on separate days). The first trial was conducted after ingestion of a
placebo solution containing water (4.5ml/kg body weight). The second trial followed the
same procedure, but subjects were given the Gatorade® solution in equal proportions of
volume. Results showed that athletes biked the distance significantly faster after the
consumption of Gatorade® (mean time = 15.9 minutes, p-value=0.0346, one-tailed t-test).
The results of the experiment strongly supported the hypothesis.
Introduction
Muscular activity of moderate intensity for
prolonged periods of time requires adequate muscle
glycogen levels and hydration. Simple carbohydrates
are usually broken down and absorbed in the intestines,
where they enter the systemic blood before reaching
muscle tissues. Once they are taken up by muscle cells,
carbohydrates provide the ATP that is necessary to
delay muscle fatigue and lactic acid buildup due to
anaerobic glycolysis (Ngyren, et al, 1998). Adequate
water intake is also required to maintain proper
hydration in muscles.
Endurance athletes are known to prefer
carbohydrate-electrolyte
rehydration
solutions
(henceforth referred to as CHO-electrolyte solutions) to
enhance performance over just water. Research by
others has supported that addition of carbohydrates and
electrolytes to a pre-performance diet enhances
muscular endurance to intense activity (Cline et al,
2000). This study will test the hypothesis that a
carbohydrate
(CHO)-electrolyte
solution
will
26
Saddleback Journal of Biology
Spring 2006
significantly enhance endurance during athletic activity
compared to water. The hypothesis is based on the
reasoning that consumption of simple sugars will
increase blood glucose levels and provide more ATP
for prolonged energy during intense activity
(Zachwieja, Costill and Beard, 1992). The intake of
electrolytes maintains a healthy intracellular
environment for maximized absorption of nutrients.
Materials and Methods
Fifteen well-trained male athletes were chosen to
participate in this study. Women were not chosen in
order to reduce variability in the results due to the
differential energy levels encountered throughout a
woman’s menstrual cycle. Participants were required to
pedal a stationary exercise bike at their own selfselected maximum tolerant pace for a distance of 8 km
in each trial. Two time-trials were conducted on
separate days that were randomly spaced apart. All
subjects participating in the trial were tested after
fasting for at least 6 hours. This precaution ensured that
varying blood glucose levels in each subject would not
affect the results. The first trial was conducted after the
consumption of a placebo drink containing artificially
sweetened and flavored water. The placebo drink did
not contain any significant amounts of carbohydrates.
Each athlete was required to consume 4.5ml/kg body
weight of the placebo drink 20 minutes before activity,
and 2ml/kg body weight every 5 minutes during
activity thereafter. The time taken by each athlete to
pedal the distance was recorded (in minutes and
seconds) in a data table in Microsoft Excel®. An
average of the completion times for the first trial was
calculated and recorded at the bottom of the table. The
same procedure was followed during the second trial;
however, participants were required to consume the
same volume/kg body weight of a 6% carbohydrateelectrolyte drink (brand name Gatorade®) before
activity. Once again, data were collected and the mean
time taken to complete the distance was calculated. A
one-tailed t-test for unequal variances was performed
to note any significant differences between the two
averages.
Results
Participants yielded a lower average completion
time for the trial conducted after the ingestion of a 6%
CHO-electrolyte solution as compared to the trial with
the placebo solution containing water (Figure 1).
Participants took an average time of 15.9 minutes to
compete pedaling a distance of 8 km after consuming
the CHO-electrolyte solution, whereas an average
duration of 17.4 minutes was taken to finish pedaling
the distance after drinking the placebo.
18
+/ - 2.2mi n
17.5
17
16.5
+/ - 1.9mi n
16
15.5
15
wit h energy drink
wit h wat er
F i f t e e n m a l e p a r t i c i p a n t s b i k e 8 k m wi t h e n e r g y
d r i n k a n d wa t e r
Fig
Figure 1. Average completion times among 15 male
participants for a distance of 8 km after the
consumption of Gatorade® drink and water. The
water trial took significantly longer than the
Gatorade® trial (p-value=0.0346 < 0.05, one-tailed ttest).
Discussion
The time it took for these two biking trials in this
experiment indicated a significant difference between
the supportive efficiencies of water and CHOelectrolyte drink upon athletes. The results, hence,
supported the hypothesis that the consumption of a
CHO-electrolyte drink enhances performance during
endurance activity compared to water.
One of the most probable reasons for the
effectiveness the CHO-electrolyte drink is that the
solution comprises of a combination of water and
complex sugars at about 6% concentration, sodium
chloride, citric acid, sodium citrate, and monopotassium phosphate which contribute to a prototype
sport and rehydration drink (Weschler and Rehrer,
2006). This well-balanced mixture, as discovered
through experimentation and detailed observation,
supplies athletes the largest amounts of temporary
energy during their exercise. Another factor is that
CHO-electrolyte drink such as Gatorade also enhances
muscular endurance due to intense activity (Cline et al,
2000). Also, the abundant amount of carbohydrates in
electrolyte drink provides the ATP necessary to delay
muscle fatigue and lactic acid buildup due to anaerobic
glycolysis (Ngyren, et al, 1998).
However, there were several variables that may
have affected the results, most of which were
controlled during the study. Possible sources of error in
this study included psychological bias (in participants)
27
Saddleback Journal of Biology
Spring 2006
toward either one of the solutions. Participants may
have worked harder with the belief that the CHOelectrolyte solution would provide better endurance
(Hausel 2001). In order to reduce this variable,
participants were not informed of the identities of the
two solutions. Also, the placebo solution containing
water was artificially sweetened and flavored to match
the taste of the CHO-electrolyte solution. Another
variable that could have influenced the experiment was
the enthusiasm of the participants. Since each subject
was allowed to pedal the stationary bike at his own
self-selected maximal pace, the participants may or
may not have worked hard enough to yield the highest
efficiency in their performance. In a best attempt to
minimize this source of error, only well-trained
competitive athletes in good form were used in the
study. All participants were required to fast for at least
six hours before the trials to reduce variability in
results due to increased blood glucose levels of some
participants. In order to avoid the effects of exhaustion
on the second trial, these trials were conducted on
separate days that were randomly spaced apart. The
ambient temperature, a smaller factor that could
influence the data, was maintained at a constant 25°C.
This experiment was carried out indoors, but in a wellventilated area.
The results of the study confirmed the belief of
most athletes about the potential of a CHO-electrolyte
drink in enhancing endurance during long stretches of
activity. They also agree with the results of other
similar studies, some of which are cited above.
Literature Cited
Cline AD, Tharion WJ, Tulley RT, et al. 2000.
Influence of a carbohydrate drink on nutritional status,
body composition and mood during desert training.
Aviat Space Environ Med.; 71(1): 37-44.
Hausel J, Nygren J, Lagerkranser M, et al. 2001. A
carbohydrate-rich
drink
reduces
preoperative
discomfort in elective surgery patients. Anesth Analg;
93:1344-1350.
Nygren J, Soop M, Thorell A, et al. 1998. Preoperative
oral carbohydrate administration reduce postoperative
insulin resistance. Clin Nutr; 17(2): 65-71.
Weschler LB, Rehrer NJ. 2006. What can be concluded
regarding water versus sports drinks from the VrijensReher experiments? J Appl Physiol; 100(4): 1433-4.
Zachwieja JJ, Costill DL, Beard GC, et al. 1992. The
effects of a carbonated carbohydrate drink on gastric
emptying, gastrointestinal distress, and exercise
performance. Int J Sport Nutr; 2(3): 239-50.
The Effects of Mycorrhizae and Fertilizer on Plant Growth in Beans, Corn and Peas
Bahador Etemadi
Department of Biological Science
Saddleback College
California 92692
The effects of mycorrhizae and fertilizer on plant growth in terms of height and width of
the leaves in three plants corn, pea, and bean were examined in a greenhouse with
controlled conditions such as temperature, humidity and light. Since a plant growth, also is
dependent on the amount of nutrients that are available to the plant root, and previous
studies on mycorrhizae and fertilizer both provided evidence that, these to factor make the
nutrients and soil elements -which are not usable to plant naturally- available to plant root;
this study focused on these two concepts. All plants were grown in controlled and equal
environment. The average height and width in corn was significantly different due to
mycorrhizae in height (p<0.01) and leaves width (p<0.01), compared to control plants,
(p<0.01) and (p<0.05) compared to fertilizer treatment respectively. There was no
statistically significant different in pea plants that treated with mycorrhizae and fertilizer
compared to control plants (non-treated) p>0.5. The significant difference in height of bean
plants only has been observed in fertilizer-treated plants (p<0.01) and no statistically
difference in mycorrhizae-treated plants (p>0.6).
28
Saddleback Journal of Biology
Spring 2006
week. The liquid fertilizer and mycorrhizal tablets
were purchased from Green Thumbs hardware store.
Results
The statistical analysis One-Way ANOVA used to
compare the effects of mycorrhizae, and fertilizer on
the plants growth (figure 1). The average growth on
plants height showed that the most significant
difference was in corn plants.
There was no
significant difference in pea’s height between the
three corn, pea and bean plants. Fertilizer was more
effective on bean plants height than the mycorrhizae
which showed no significant difference between
Control and Mycorrhiza in statistical analysis. The
width of the leaves also improved by mycorrhizae in
corn, and pea plants P<0.01 between Control and
Fertilizer and P<0.01 between Fertilizer and
Mycorrhizae, (figure 2). There was no significant
difference in the width of the pea leaves. The
mycorrhizae did not improve in beans leaves width,
but there was a significant difference (P<0.01 between
Fertilizer and Mycorrhizae and P<0.05 between
Control and Mycorrhizae).
120
Control
Fertilizer
100
Mycorrhiz
Plant Height (cm)
Introduction
In today’s life most the biologist, geologist,
doctors and even economics- researchers concern
about the ways that technology has been replaced by
natural resources, and the effects of these
replacement on human’s life (health), and other
earth creatures. The study of the mutual
relationships between different organisms for more
than hundreds of years have grabbed the biologist
attention and more specifically, the symbiosisinteraction of plant and fungi has been one of the
most popular fields in this matter. This experiment
tried to reach an accomplishment in the relation
between three plants (corn, bean and pea) and
mycorrhizae (a fungus that lives in the plant root),
and compare the effects of plant-fungi symbiosis
and liquid fertilizer (plant food). While the other
factors like amount of light, CO2 concentration,
temperature and soil salinity (Anthraper A, and
Dubois J. 2003) which are really important in plant
growth kept equal. In one hand our expectation was
that mycorrhizae should improve the plant growth
(Wilson G. and Hartnett D, 1997; Hartwing U.A, et
al 2002; Wilson G, et al 2001). On the other hand,
the effects of fertilizers in today’s gardening are
undeniable. The plant growth mostly limited to
amount of soil nutrients such as phosphorus
(Poulton J, et al. 2001) and nitrogen (Knowles R,
and Rise S. 1981; Sage R, Pearcy R. 1987).
In
comparison of these two sources, as food provider to
the plant root, one from nature, and one born with
human advanced technology, we expect that, “In all
cases mycorrhizae should have more significant
effects than fertilizer on plant growth.”
80
60
40
20
0
Corn
Pea
Bean
Figure 1. Average height in corn, pea and bean plants,
which have been treated by different sources of nutrients.
The biggest different in mycorrhizal plant was in corn and
no significant difference seen in pea and bean.
8
7
Leaves Width (cm)
Materials and Methods
Plastic pots filed with non-treated potting soil,
with no mycorrhizae content. For mycorrhizae
treatment added one mycorrhizal tablet, which was
placed at one third from the bottom of each pot.
Each tablet in addition to spores of mycorrhizae
contained the following nutrients: Total Nitrogen
17%, Phosphate P2O5 9%, Soluble Potash K2O-5%,
Mycorrhiza in Clacined clay-45%, Humic Acid
drived from leonardiate CDFA-metod-35% and
Ascophyllum Nodosum-20%. Seeds were planted
about 1.5 inches from the surface of the soil. All the
pots then placed on March 2nd in the greenhouse
located at (Saddleback College) Mission Viejo, CA.
and the data were collected three weeks after. The
liquid fertilizer contents were the following: Total
Nitrogen N-10%, Phosphorus P2O5-15%, Soluble
Potash K2O-10%, Iron Fe-10%, Manganese Mn0.05%, and Zinc Zn-0.05%; which added every time
by dissolving it in water. Plants watered twice a
Control
Fertilizer
Mycorrhizae
6
5
4
3
2
1
0
Corn
Pea
Bean
Figure 2. The average width of the plant leaves improved
by mycorrhizal treatment in corn plants. There was no
significant difference in pea plants. The width of the leaves
significantly differ in bean plants.
29
Saddleback Journal of Biology
Spring 2006
Discussion
There was not enough evidence to support the
hypothesis that, mycorrhizae have the most effects
on all of plants growth (corn, pea, and bean), but
fertilizer in bean had the best results in terms of both
height and the width of leaves on corn plant (P<0.05
between Fertilizer and Mycorrhizae, P<0.01
between Control and Mycorrhizae). Mycorrhizae
and fertilizer did not improve the growth of pea
plant (result of no significant difference by statistical
analysis). As the results showed mycorrhizae had
negative effects on bean plant (P<0.01 between
Control and Fertilizer). These results are in contrast
to (Wilson G. and Hartnett D, 1997; Hartwing U.A,
et al 2002; Wilson G, et al 2001) studies. In these
two cases not mycorrhizae, but other factors like the
amount of nitrogen and phosphorus were more
efficient on that plants growth. These results support
(Knowles R, and Rise S. 1981; Sage R, Pearcy R.
1987; Poulton J, et al. 2001). In conclusion, these
two factors -mycorrhizae and fertilizer- were not
effective on pea plants in short period (3 weeks)
p>0.5 but overall, they improve the growth in corn
and bean. Another important case that observed
during this time was that the plants that growth on
fertilizer had a rapid growth at the beginning that
they could not support their body weight, but the
plants that were mycorrhizae dependent had a
constant growth and they were stronger than control
and fertilizer plant.
Hartwig U, Wittmann P, Braun R, Hartwig-Raz B,
Jansa J, Mozafar A, Luscher A, Leuchtmann A,
Frossard E, Nosberger J. 2002. Arbuscular
Mycorrhiza Infection Enhances The Growth Response
of Lolium perenne to Elevated Atmospheric pCO2.
Journal of Experimental Botany. 53(371): 1207-1213
Knowles R, Ries S. 1981. Rapid Growth and Apparent
Total Nitrogen Increases in Rice and corn plants
Following App;ication of Triacontanol. Plant Physiol.
68: 1279-1284.
Poulton J, Koide R, Stephenson A. 2001. Effects of
Mycorrhizal Infection and Soil Phosphorus
Availibility on in Vitro and in Vivo Pollen
Performance in Lycopersicon
esculentum (Solanceae). American Journal of Botany.
88(10): 1786-1793.
Sage R, Pearcy R. 1987. The Nitrogen Use Efficiency
of C3 and C4 plants. Plant Physiology. 84: 954-958.
Wilson G, Hartnett D. 1997. Effects of Mycorrhizae
on Plant Growth and Dynamics in Experimental
Tallgrass Prairie Microcosms. American Journal of
Botany. 84(4): 478-482.
Literature Cited
Anthraper A, and Dubois J.2003. The Effect of NaCl
on growth, N2 Fixation (Acetylene Reduction), and
Percentage
Total
Nitrogen
in
Leuceaena
leucocephala (Legguminosae) Var. K-8. American
ournal of Botany. 90(5): 683-692.
30
Saddleback Journal of Biology
Spring 2006
The Effect of Nitrogen Fertilizer on the General Growth Habit in Tomato Plants
(Lycopersicon lycopersicum)
Nikki Kopan and Avisha Tamimi
Department of Biological Sciences
Saddleback College
Mission Viejo, CA 92692
Nitrogen is the macronutrient that is necessary for tomato plant growth and color.
During the spring the plants require more nitrogen, and so it is depleted from the soil more
quickly. In this experiment, the effects of high and low nitrogen concentrations on Roma
tomatoes (Lycopersicon lycopersicum) were studied. One group was treated with a fertilizer
that contained 18% nitrogen, and the other group was treated with 5% percent nitrogen. A
third group was given only water for comparison 0% nitrogen. Plant heights were
measured every two after the initial planting to monitor the growth. The average growth
was calculated between the final and the initial measurements, for each group. The average
growth of the tomato plants at 0%, 5%, and 18% nitrogen concentration was not
significantly different, as was determined by the ANOVA and post-hoc analyses, (p= 0.132).
Data did not support the hypothesis, as it had been predicted that the higher concentration
of nitrogen would cause a greater amount of growth. The plants that were treated with
high concentrations were noticeably healthier. The plants that were treated with water or
low concentrations showed slight symptoms of nitrogen deficiency.
Introduction
When considering a fertilizer for the tomato
plant, the chemical makeup must contain the proper
balance of the main nutrients.
Nitrogen,
phosphorus, and potassium are macronutrients that
are depleted from the soil the most quickly, as they
all affect the overall health and growth of the plants.
The element essential for vegetative growth and rich
green color, is nitrogen, as it is a constituent of plant
proteins, chlorophyll, amino acids, and other plant
substances (PSU). In order for the plant growth to
be the most efficient, the concentration cannot be
too high or too low as both situations can cause
detrimental effects on the growing tomato plants.
Average nitrogen concentration needed for normal
growth is about 4% for tomato plants (Tamimi et,
1994). According to a previous study, nitrogen
stress resulted in fewer and smaller, but thicker,
leaves (Scholberg et al., 2000). An excess of
nitrogen can pollute the ground water and decrease
the efficiency of nitrogen fertilization in the tomato
plant (Fontes,2002). The risk for excessive nitrogen
with consequent nutrient losses includes nitrate
leaching and damaged fruits, is increased if the
amount of fertilizer needs to be increased to meet
the demands of the 20 limiting nutrients, including
sulfur and phosphorus (Heeb, 2005). Organic
fertilizers do not usually contain the over-saturation
level of the important nutrients. Synthetic fertilizers,
often contain the three important nutrients, nitrogen,
phosphorus, and potassium, in concentrations of 10%
or greater. Management practices can influence soil
carbon, nitrogen, and the tomato (Lycopersicon
esculentum) yield (Sainju et al, 2002). Organic or
synthetic fertilizers are not the major factors affecting
yield and product quality. A balanced nutrient supply
is important for yield and quality, regardless of the
nutrient source. The purpose of this experiment was
study the effects of nitrogen fertilizer on the general
growth habit of the tomato plant. It was predicted
that, the greater the concentration of nitrogen in a
fertilizer, the greater the plant growth and health.
Materials and Methods
Three groups of ten Roma tomato seedlings
(Lycopersicon lycopersicum) were planted in
individual pots with a uniform potting soil and grown
under greenhouse conditions at Saddleback College.
The temperature and amount of sunlight was constant
for all the plants. One group was given the synthetic
fertilizer, Miracle-Gro Water Soluble Tomato Plant
Food with a nitrogen percentage of eighteen. The
second group was given Dr. Earth Organic 5 Tomato,
Vegatable, and Herb fertilizer, with a nitrogen
31
Saddleback Journal of Biology
Spring 2006
percentage of five. The third group was given only
water for comparison purposes as a control group.
The organic fertilizer was mixed in with the soil
only during the initial planting, as it was to be used
every two months as per the directions. It was
composed of mostly insoluble nitrogen and so would
not be easily removed from the soil during the
watering, extending the effectiveness of the
fertilizer. The synthetic fertilizer was applied every
two weeks, as was directed for best results. The
fertilizer was applied more frequently because it
contained mostly water-soluble nitrogen which is
more easily removed from the soil.
Plant
measurements were taken every two weeks to
monitor growth. All plants were watered as needed.
The plants were staked with bamboo rods, during
the fifth week, enabling the plants to grow straighter.
The study was conducted for seven weeks. The
Microsoft Excel Program was used for data analysis,
and GraphPad Software was used for the Post-Hoc
analysis.
Results
Statistical analyses (ANOVA and Post-Hoc) were
conducted and indicated that there was no
significant difference in tomato plant growth rate
between any of the groups tested (ANOVA, p =
0.132).
The average growth rate was 17.9
centimeters for the water only group, 24.01
centimeters for the organic fertilizer, and 23.47
centimeters for the synthetic fertilizer (Figure 1).
The stalks of the water and low nitrogen
concentration groups were thinner than those of the
high nitrogen concentration group. The leaves of the
high nitrogen group had a richer green color.
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
0
5
18
N i t r oge n P e r c e nt a ge
Figure 1 There was no difference between the
height of the plants (p = 0.132).
Discussion
Results indicated that the low concentration of
nitrogen caused a slightly larger increase in average
growth, but the difference in the average growth rate
change was less than one centimeter. The presence of
nitrogen in the fertilizer did cause an increase in the
growth of the tomato plant that was greater than the
water only group, though the difference was not
significantly different between any of the tomato plant
groups. The data does not support the hypothesis,
which had predicted an increase in growth among the
plants that had the higher concentration of nitrogen.
The plants treated with the Miracle-Gro were overall
the healthiest of the three groups. The plants had
stems that were thicker, with larger, darker leaves.
The high nitrogen concentration affected all aspects of
the growth of the tomato plants, not only the height.
The Miracle-Gro fertilizer supplemented the growth of
the plant by enhancing the color and size of the leaves,
thereby contributing to the overall aesthetic
appearance of the tomato plants. The presence of
nitrogen affected the growth, but the higher
concentration of the nitrogen did not force the plant to
grower taller, instead contributing to other plant
functions. The water only group and the low nitrogen
concentration group appeared to have nitrogen
deficiencies. The leaves were lighter, and the older
leaves at the bottom yellowed. Bumps formed on the
stalk, which also indicated that there were nitrogen
deficiencies. All the plants were stalked during the
fifth week to maintain uniformity. The water group
and low nitrogen concentration group had a greater
need for the stalks as many of them were no longer to
support their frame. The high nitrogen concentration
group continued to grow healthier though, the large
amount of vegetation created a need for stalks, as
support.
Adding nitrogen beyond the necessary amount for
growth and crop requirement will cause nitrate
leaching, because plant cannot absorb the excess of
such nutrients (Fontes, 2002). However, organic
fertilizers do not always supply enough of a nutrient,
and so can be supplemented through the use of
mineral fertilizers or salts to correct any deficiencies
(Heeb, 2005). The organic fertilizer may be less
harmful to the environment, but it is not necessarily
the best for the plant. Nitrogen deficiencies can slow
the growth rate, causing the leaves to be small and
pale-colored, sometimes even yellow. The cause of
the discoloration is the decreased amount of nitrogen
in the soil affects the amount of chlorophyll, thus
affecting the green color.
The fertilizers used were chosen for their nitrogen
concentration. One was synthetic and the other was
organic. Nitrogen is the element that primarily acts as
32
Saddleback Journal of Biology
Spring 2006
the building blocks of the plants and is responsible
for growth. The levels of potassium and phosphorus
were not the same in the fertilizers, but were
responsible for elements irrelevant to the study
conducted. The potassium was responsible for
physiological functions and disease resistance, and
the phosphorus was responsible for good root
development and plant energy.
Literature Cited
A Guide to Turfgrass Maintenance Fertilization. The
Pennsylvania State University. Department of Crop
and Soil Sciences - Cooperative Extension. (2006)
Fontes, P. C. R. and Ronchi, C. P. (2002). Critical
values of nitrogen indices in tomato plants grown in
soil and nutrient solution determined by different
statistical procedures. Pesq. agropec. bras., vol.37,
no.10, p.1421-1429.
Heeb, Anuschka (2005) Organic or mineral
Fertilization. Doctoral Diss. Dept. of Crop Production
Ecology, SLU. Acta Universitatis agriculurae Sueciae
vol. 2005: 73
Scholberg, J., McNeal, B.L., Boote, K.J., Jones, J.W.,
Locaio, S.J., and Olson, S.M. (2000). Nitrogen Stress
Effects on Growth and Nitrogen Accumulation by
Field-Grown Tomatoes. Agronomy Journal 92:156167
Tamimi, Y., Silva, J.A., Yost, R.S., and Hve, N.V.
(1994). Adequate nutrient levels in soils and plants in
Hawaii. Soil Sci. Plant anal. 21:61-73
Sainju, U.M., Singh,B.P., and Yaffa, S. (2002). Soil
Organic Matter and Tomato Yield following Tillage,
Cover Cropping, and Nitrogen Fertilizaion. Agronomy
Journal 94: 594 – 6
Effect of Pigmentation on Male Betta Fish (Betta splendens) Interactions
Tonika Lam and Supriya Chaudhary
Department of Biological Sciences
Saddleback College
Mission Viejo, CA 92692
Dominant pigmentations associating with animals that are characterized by sexual
dimorphism are important factors in intersexual selection. Male and female B. splendens
demonstrate dilated gills when presented with one another. Males display themselves in a
hostile manner through gill flare and increase their body mass when they are in the
presence of a female. During the mating ritual the female will dilate her gills in return
when there is an establishment. Hierarchies are established when a male defeats a less
fierce male to achieve sexual reproduction with a female. Red is a vibrant color that is
usually associated with dominance and sexual attraction. In this experiment, two female
betta fish were presented with two male B. splendens, with one of the different hues of red
and blue in a tri-partitioned tank filled with dechlorinated water. Time was recorded in
seconds when the female exhibited concordance with the male through dilated gills as well
as the hue the female chose to mate with. A five minute resting period was allowed between
each trial for the male and female betta fish. The results supported the hypothesis that red
pigmented B. splendens had a significantly larger measure of concordance establishments
by the female (p=0.022, Chi Square), thus making the red male betta fish the more desired
hue out of the two groups of males.
Introduction
Reproduction is a fundamental behavior and
characteristic that many animals display. It is realized
that the true measure of success be an individual, in
the evolutionary sense is not survival but the number
of offspring produced (Merrel, 1948). Individuals
that survive and produce support the derived theories
of natural selection and sexual selection. Animal
selection is influenced by physical attributes such as
sexual appearance, body mass and color.
33
Saddleback Journal of Biology
Spring 2006
Siamese fighting fish B. splendens demonstrates
sexual dimorphism between males and females. Male
B. splendens are highly ornamented (Doutrelanta,
McGregora and Oliveirab, 2001) where as the
females are less decorative and usually smaller in
mass. B. splendens exhibit intersexual selection or
mate choice between the males and the females and
intrasexual selection between just the males. Females
choose to mate with the male that is highly
ornamented and displays an intense amount of
conspicuous behavior. (Fantino, Weigele and Lancy,
1972). Males are highly aggressive towards one
another (Fantino et al., 1972) and when presented
with a female males increase to a dominant behavior
that can be used in communication with both males
and females where aggressive displays are solely
directed to males (Doutrelanta, McGregora and
Oliveirab, 2001). Aggressive displays can range to
slight change and increase in color vivacity (Peake
and McGregora, 2004) to obvious aggressiveness
often displayed by the flaring of the gill operculum
(Fantino, Weigele and Lancy, 1972).
Pigmentation contributes to an animals
characteristic behaviors for communication with
other animals to use as a form of defense or attraction
towards the opposite sex. A rank- dependant red
coloration on the face (Setchell and Wickings, 2005)
of male mandrills Mandrillus sphinx increase
vivacity as the more dominant the male becomes.
Red is a dynamic hue where it shows a sense of
power and control where as a blue hue is calm and
relaxing which can be associated with positive
emotions (Boyatzis and Varghese, 1994).
This study addresses the association of
pigmentation in male B. splendens in the
concordance of a female in their mating ritual. Red
hues coordinate in nature to show a sign of
dominance and aggression (Setchell and Wickings,
2005) . It is hypothesized red male pigmented B.
splendens with have a greater measure of
concordance with the female than the blue pigmented
B. splendens.
Methods and Materials
Two female B. splendens and two male B.
splendens were purchased from Petsmart (Aliso
Viejo) which included one red male and one blue
male betta fish. Each B. splendens was fed four Betta
Bites (HBH Pet Products) daily. B. splendens were
kept isolated until trials were tested in the
environment of 37-40oC.
A tri-partitioned fish tank was created by placing
two colorless glass plates, forming a V-shape
midway of the tank. The fish tank was filled with
dechlorinated water in order to ensure the oxygen
content was adequate for the betta fish.
The females (N=2) B. splendens were assigned
into two different groups for organization purposes.
A total of twelve trials were tested, six for each
female. One female was placed in between two of
partitions for each trial, with the red male in one
corner and a blue male in the other. This allowed the
female to be presented to both males and the female
to be able to view both males of different hues. A
stop watch was used to record the time(s) taken for
the female to display concordance based on the color
of choice through gill flare. This process was then
repeated until each female reached a total of six
trials, allowing a five minute resting period for the
males and females.
Using Microsoft Excel (Microsoft Corporation),
the data was then analyzed. Chi square was used to
determine whether the red male betta was
significantly a more desirable hue than the blue betta
fish. Where p<0.05 was considered to be significant
between the red and blue male. The two variables for
the experiment was the amount of time it took for the
female to establish concordance with the color of
male for her mate choice
Results
The females established a concordance with the
male that displayed the most dominant characteristic
and aggression between the two males. The time was
taken in seconds when the female betta fish dilated
gills in response to the male of her discretion. The
measurement of the amount of time for the female B.
splendens to select the red male B. splendens was
eight, for the blue male betta fish the selection
amount from the female was four (Figure 1). There
was a significant difference between the red and blue
betta fish in the females discretion of hue for a male.
The average amount of time for the female B.
splendens to give concordance to the red male was
382.8 seconds and the average time for the blue male
to receive concordance from the females was 49.75
seconds. Red B. splendens have a significantly larger
measure of selection from female B. splendens (Chi
Square, p= 0.022). The shortest time recorded for the
red male B. splendens to receive concordance from
the female was 125 seconds and the longest time
recorded was 1347 seconds, whereas the shortest
time taken from the female for the blue male B.
splendens was 18 seconds and the longest time to
receive concordance was 91 seconds (Figure 1). Chi
Square showed red male betta fish to be more
significantly appealing to females for the total
34
Saddleback Journal of Biology
Spring 2006
outcome of discretion from females in relation to the
time it took for each trial.
Female B. splendens
10
8
6
4
2
0
red
blue
Color of Male betta fish
Figure 1. The number of discretions performed
by the female Betta splendens (N=2) between the
red male betta (N=1) and blue male betta (N=1)
through dilated gills. Chi Square showed
p=0.022, therefore red male betta fish are
signifigantly more desired
amount of seconds it took for red B. splendens to
dilate gills compared with the blue B. splendens.
These results support that red pigmented B. splendens
is more aggressive than the blue pigmented B.
splendens. Red hues are characteristics of dominance
(Doutrelanta, McGregora and Oliveirab, 2001) and is
a hue that is sexually appealing in nature.
Hostility by male B. splendens is produced to
manifest dominance towards other males (Peake and
McGregora 2004) and sexual appearance and
behavior when performing mating rituals with female
B. splendens are presented (Doutrelanta, McGregora
and Oliveirab, 2001). The different degrees of
aggression are due to the presence of dominance and
sub-dominance in B. splendens. (Peake and
McGregora, 2004). The varying pigmentations of
competing male B. splendens may affect the
aggressive behaviors B. splendens display when
encountered with one another.
Literature Cited
Boyatzis CJ, Varghese R. 1994. Children’s emotions
associated with colors. 155(1):77-85.
Discussion
In the amount of discretion performed by the
female betta fish and the time it took for the female to
response through dilated gills, red male betta fish are
significantly more appealing to females. The results
support the hypothesis that red male B. splendens will
have the most number of outcomes from female B.
splendens, thus making them the hue that females
prefer. The different levels of aggressive behaviors
that attract females are influenced by dominating B.
splendens (Fantino, Weigele and Lancy 1972) to
provide a less latency to dilate gills than the
intimidated B. splendens.
Red B. splendens are highly aggressive than blue
B. splendens, according to a previous study the
shortest time for red B. splendens to dilate gills was
92 seconds while the shortest time for the blue B.
splendens was 661 seconds (one- tailed t-test, p=
0.023). There was a significant difference in the
Doutrelanta, Claire. McGregora, Peter K. Oliveirab,
Rui F. 2001. The effort of an audience in intrasexual
selection communication in male Siamese fighting
fish, Betta splendens. Behavioral Ecology 12(3): 283286.
Fantino, E. Weigele F, and Lancy D. 1972.
Aggressive display in the Siamese fighting fish.
Learning and Motivation. (3): 457-468.
Merrel David J. 1949. Selective mating in Drosophila
Melanogaster. Genetics 34: 370-389.
Peake, Tom M. and McGregor, Peter K. 2004.
Information and aggression in fishes. Learning and
Behavior. 32(1): 114-121.
35
Saddleback Journal of Biology
Spring 2006
The Effect of Salinity and Temperature on the Metabolic Rate
of Goldfish (Carassius auratus)
Dean Brown and Tom Beckstead
Department of Biological Science
Saddleback College
Mission Viejo, CA 92692
The metabolic rates of three groups of goldfish were tested at three different
temperatures (7 ºC, 17 ºC, and 27 ºC). The metabolic rate of the goldfish acclimated in the
7 ºC solution will have a lower opercular pumping rate than the gold fish acclimated in the
other two solution (17 ºC, and 27 ºC). All three groups were acclimated for a week in water
with a salinity of 7 ppt. There was a significant difference between all three groups
metabolic rates (p= 0.0000 ANOVA). The goldfish acclimated in the 7 ºC had a significantly
lower metabolic rate ( x = 50.6 per minute) then the other two groups water ( x = 69.9 per
minute at 17 ºC and x = 129 per minute at 27 ºC). The Q10 from 7 ºC to 17 ºC was 1.37 and
from 17 ºC to 27 ºC was 1.87. This was possibly due to higher oxygen levels in the colder
water or the stress of the goldfish entering a new environment.
Introduction
There are many types of fish that are found in
lakes, rivers, oceans and ponds. These fish have
evolved over millions of years and have adapted to
their preferred environment (Hurst and Conover
2002). Fish are categorized according to the
amounts of salinity that they can tolerate For
example, a goldfish and tuna fish can survive in
narrow ranges of salinity. Goldfish (Carassius
auratus) have evolved to prefer freshwater over salt
water. Although goldfish can live in many types of
osmotic environments, their normal habitat is fresh
water; they can easily cope with mildly salty waters.
Goldfish can sustain life by obtaining oxygen
in water by ventilating their gills. The operculum, a
protective flap, covers and protects the soft and
delicate gills (Figure 1). The gills are ventilated by
pumping water across them in one direction. Both
the mouth and operculum work together to pump the
water through the mouth, into the gills and then out
to the sides of the body (Weng, et al., 2002). As the
water saturated with oxygen moves over the gills,
gas from the water diffuses via the gills to the blood.
At the same time carbon dioxide moves from the
gills out into the water. The frequency of these
“breathing” movements over a specific period of
time provides a measure of ventilation rate
(McKenzie, et al., 2001). Thus, if the goldfish are
placed in an environment that they are unadapted to
then they will struggle to survive. In other words,
goldfish placed in salty water will have a higher
opercular pumping rate than freshwater.
Temperature is another major variable that can
affect the opercular pumping rate of fish. The warmer
the water temperature, the lower the O2 levels will be,
thus the opercular pumping rate will increase to
sustain a constant level of oxygen in the fish. The
lower the ambient temperature, the lower the
opercular pumping rate will be. Testing goldfish at
temperatures that vary by ten degrees Celsius, affects
the opercular pumping rate. For every increase of the
ambient temperature, the goldfish will double its
opercular pumping rate; this is referred to as the Q10
rule (Gillooly et al., 2001).
Goldfish are
poikilothermic ectotherms, meaning they are able to
adapt to different temperatures just like they can
adjust to different salinities due to their high thermal
conductance (Boeck et al.,1996). Testing both salinity
and temperature will help one learn more about how
goldfish are able to adapt to changing environments.
Figure 1. Goldfish anatomy (note operculum)
36
Saddleback Journal of Biology
Spring 2006
Results
The average opercular pumping rate for the
goldfish in the 7 ºC salt water was 50.6 times per
minute. The average goldfish in the 17 ºC salt water
was 69.1 times per minute and the average opercular
pumping rate for the goldfish in the 27 ºC was 129
per minute. Each fish was measured three times so
there was a total of thirty measurements.
There was a significant difference between these
three groups (ANOVA p=0.000). There was a slight
increase in the opercular pumping rate in each of the
three trials.
Average opercular pumping rate
Material & Methods
Three groups of ten goldfish were bought at
Petco in Rancho Santa Margarita, CA and were
placed into three different 19-liter buckets filled
with reverse osmosis water or R.O. water. R.O.
water is purified water that has filtered out particles
as small as ions, salts and other impurities from a
solution. Each group was acclimated at different
temperatures (7 ºC, 17 ºC and 27 ºC) with (RO)
water for one week. The 27 ºC bucket was
maintained by a heater (WON pro-Heat IC Heater
350 W®). The 17 º C bucket was placed in a house
garage and the 7 ºC bucket was maintained in a
refrigerator to keep the temperature maintained. All
buckets had a thermometer to help gauge the water
temperature. The fish were fed once a day in the
morning with fish pellets (Warldley’s goldfish slow
sinking crumbles). Each bucket was equipped with
the proper aeration, by using an air pump (Hagen
®). Attached from the pump was tubing with an
aeration stone (Aquatic Gardens ®). This generated
many bubbles to aerate the H2O and transport toxins
from the substrate to the surface for dissipation.
To obtain the proper concentration of salt water
(7 ppt) for the fish to be acclimated and tested in, a
scientific grade marine salt (Coral Life ®) was
added and stirred. After 30 minutes of having the
salt settle, a refractometer (Captive Purity ®) was
used to measure the salt concentration. The fish in
their respected bucket were acclimated for a week.
This allowed for a heightened outcome and for the
fish to get adjusted to their new environment.
During the experimentation, three 250 ml
beakers were placed and filled with one of the
buckets salty water. Each fish was tested only in
the water that they were acclimated in. This allowed
the data to be constant and to see if the temperature
has an effect on the metabolic rate of the goldfish.
The opercular movements of each fish were counted
for one minute three times with 30 seconds of rest
between the next minutes of counting. To make sure
each fish will only be tested once, each fish was
placed into a separate container filled with the same
temperature they were acclimated in.
140
120
100
80
60
40
20
0
7 ºC
17 ºC
27 ºC
Figure 2 The average opercular rate
of three groups of ten goldfish were
measured at three temperatures 7, 17,
27 degree C. There was a significant
difference between all three groups.
Q10 was calculated for each 10°C increment in
temperature using the equation below. Q10 for 7 to 17
ºC was 1.37. For the temperatures from 17 to 27 ºC it
was 1.87.
Q10= (R2/R1)10/(T2-T1)
Discussion
Based upon the results, there was a significant
difference in the opercular pumping rate between all
three groups of goldfish. In the three trials, the mean
of the opercular pumping rate of the ten fish did not
doubled from 7 ºC
and 17 ºC or 17 ºC to 27 ºC. This did not follow the
Q10 rule. (Gillooly et al., 2001).
Once the salt water goldfish group was placed in
the 7 ppt water, they swam around franticly due to the
lack of oxygen. This caused their opercular gills to
work overtime to sustain oxygen levels to keep them
alive. The goldfish did settle down once they had
been in the solution for a while This is due to their
tremendous adaptation capabilities these goldfish have
(Boeck, et al., 1996). This observation was also
present in McKenzie’s (2001) study, which was to
determine how salinity affects the fishes exercising
performance.
Although McKenzie didn’t use
goldfish, he did however use another fresh water fish,
the Adriatic Sturgeon (Acipenser naccarii). Mckenzie
37
Saddleback Journal of Biology
Spring 2006
found that the sturgeon was more active in the fresh
water due to the oxygen availability in the water and
since this was their normal environment. With the
same fish placed in a higher salinity for a 24 hour
period, he noticed a reduced amount of energy in the
fish. This could be due to the lack of oxygen in the
water.
Hurst and Conover (2002) have conducted
similar studies with a much larger fish, the striped
bass (Morone saxatilis) in the Hudson River and
experimented with different variables, such as
salinity, body size and varying temperatures. Using
salinities from 0 ppt to 35 ppt, these biologists’
findings were very fascinating. Their results show
that at lower temperatures, the striped bass were able
to flourish at higher salinity levels.
The goldfish used in this experiment are very
similar to the Adriatic Sturgeon and striped bass
experiments because they all deal with how salinity
affects behavior.
One could hypothesize that
goldfish closely moderated for an extensive period
of time when their ambient temperature changes
from 17 ºC to 7 ºC will have a better chance of
survival than the fish from 17 ºC to 27 ºC.
Literature Cited
Baker E, Glesson T. 1999. The Effect of Intensity on
the Energetics of Brief Locomotor Activity. Journal
of Experimental Biology. 202: 3081-3087.
Boeck G, Nilsson G, Vlameinick A, Blust R. 1996.
Central Monominergic Response to Salty and
Temperature Rises in Common Carp. The Journal of
Experimental Biology. 199: 1605-1616
Gillooly J, Brown J, West G, Savage V, Charov E.
2001. The Effect of Size and Temperature on
Metabolic Rate. Science. 293: 2248-2251.
Hurst T., Conover D., 2002. Effects of temperature
and salinity on survival of young-of-the-year Hudson
River striped bass (Morone saxatilis): Implications for
optimal over wintering habitats. 59: 787-794
McKenzie D.J., Cataldi E., Ramano P.,
Talylor
E.W., Cataudella S., and Bronzi P. 2001. Effects of
acclimation to brackish water on tolerance of salinity
challenge by young-of-the-year Adriatic sturgeon
(Acipenser naccarii) Canadian Journal of Fisheries
and Aquatics Sciences. 58: 1113-1121
Weng, Chiang, Gong, Chih Chen, Fan Lin, Huang,
Cheng, Hwang, Wu. 2002. Acute changes in gill Na.
sup- K. sup ATPase and creatine kinase in response to
salinity changes in the euryhaline teleost, tilapia
(Oreochromis mossambicus) Physiological and
Biochemical Zoology 75: 29-3
The Effect of Antagonist Image Size on Latency to Aggression in Male Betta Fish
(Betta splendens)
Camilo Avendano and Darryll Sulindro
Department of Biological Sciences
Saddleback College
Mission Viejo, California 92692
Differences in size are often key elements in deciding dominance and sexual selection in
animals. Six Male Betta fish (Betta splendens) were exposed to three different sized images
to observe whether larger sized images would invoke shorter latency to aggression. The
time taken for them to show aggression through opercular gill flaring was measured and
tabulated. The Betta fish had significantly different latency to aggression when exposed to
the three different sized images (P=0.003, ANOVA test). However, there was no significant
difference in the latency to aggression for Betta fish exposed to medium and large images
(P=0.29, one-tailed t-test).
Introduction
An organism’s ability to defend itself in
dangerous situations is vital to its survival.
Evolution and natural selection has forced living
organisms to evolve into forms that enable them to
defend themselves against enemies or give them the
38
Saddleback Journal of Biology
Spring 2006
capability of fleeing a predator (Douglas, 2006)
Among one of the organisms that has developed a
trait which enables it to scare off enemies and
predators are Betta fish (Betta splendens).
Betta fish inhibit shallow waters and moving
streams in Thailand, Indonesia, Malaysia, Vietnam,
and parts of China. An interesting characteristic of
Betta fish is their aggressive and hostile behavior
towards other Betta fish and fish of the same size.
Like males of other species, Betta fish have different
levels of aggression due in part to the males showing
superiority in mating and in sexual selection when a
female is present (Doutrelanta et al, 2001). When
threatened from an enemy the Betta fish will also
flare its opercular gills to show its aggression. The
measure of aggressiveness of Betta fish is based on
the latency for Betta fish to reach full blown
aggression, which is shown by the flaring of the gills
(Fantino, et al., 1972).
Betta splendens have a tendency to become
agitated and aggressive towards other male Betta
fish and other fish of similar size and colors
(Doutrelenta, et al., 2001). This allows research into
finding out what kind of stimuli encourages displays
of aggressive behavior. Bando showed differences in
agitation when Betta fish are exposed to fish pictures
of different textures. (Bando, 1991). In the Fall of
2005, Lam and Sulindro determined that color of the
Betta fish had a correlation with its aggressiveness.
The current hypothesis is that Betta fish will have
shorter latency to aggression when exposed to larger
sized images.
In this study, male Betta splendens will be
exposed to different size pictures of other Betta
splendens to simulate an attack on the fish which
will make the Betta fish become aggressive. The
latency for the fish to react to the pictures (the
reaction time it takes for their opercular gills to
flare), will be recorded and will enable us to know
whether the size of a predator or enemy has a direct
correlation to the latency of opercular flaring. The
quicker the gills flare the more aggressive the
creature is. This study will help researchers further
understand the different methods that not only Betta
fish, but other animals relate with aggression, and
will help determine whether many fish are
aggressive based on visual stimuli instead of smell,
touch and other senses.
and approximately the same size to avoid error in data
since different colors and sizes of Betta fish have
shown to be more aggressive than others (Lam and
Sulindro, 2005). A 3 X 1.5” picture of a blue male
Betta fish was taken online and used as the aggressor
to the fish subjects as this was the average size for
male Betta fish. Three different sizes of the same
picture were made. The smaller sized picture was
150% smaller than the medium one, and the large
sized picture was 150% times larger than the medium
picture.
Each Betta fish was placed into a 6 X 3 X 4” clear
plastic tank. When the fish was placed into the tank it
was given three minutes to adapt to its new
environment. After the three minutes, the smallest
picture of the Betta fish was placed along the tank
sides. In order to minimize visual interferences, three
sides of the tank were covered with white paper. With
a stopwatch, the timer began as soon as the picture
was placed on the outer tank walls. The image was
attached to a clear plastic straw and was waved in
front of the fish in a lively manner. Once the opercular
gills flared, the time was recorded. The fish was then
taken out of the tank and the process was repeated
with the other fish.
In order to reduce the possibility of the Betta fish
being worn out from their shows of aggressions which
could possibly affect the results, the medium and large
sized image experiments were repeated individually
on separate days. This allowed sufficient resting
periods for the Betta fish. Data were analyzed using
Microsoft Excel.
Results
The average time taken for the Betta fish to show
aggression when presented to the small images was
905 seconds, while the average time for the Betta fish
to show aggression when presented the medium and
large images was 255 and 230 seconds respectively.
Betta fish have significantly different latency to gill
flaring when subjected to the three different sized
images (ANOVA-test p=0.003). However, there was
no significant difference in the latency to aggression
between the medium sized images and the large sized
images (p=0.29, One-tailed t-test).
Materials and Method
Six Betta fish (Betta splendens) purchased at
Petco, Mission Viejo, were placed in separate 3 X 2”
bowls. All six fish were males, since males have
shown to be more aggressive than females
(Doutrelanta, et al., 2001). All Betta fish were blue
39
Saddleback Journal of Biology
Spring 2006
1000
900
Tim e (seconds)
800
700
600
500
400
300
200
100
0
Small Image
Medium Image
Large Image
Fig 1. Average time taken for betta fish (n=6)
to show aggression through gill flaring when
exposed to 3 different sized images. Anova test
showed p=0.003 which shows significance.
Discussion
The latency to show aggression through flaring
for the Betta fish (Betta splendens) showed that
when exposed to the medium and large sized
images, Betta fish had a significantly shorter time to
show aggression than when exposed to the smaller
image. However, there was not a great significant
difference between the times for the medium and the
large sized images.
Results support our hypothesis that Betta fish
would be quicker to aggression when faced with
larger opponent Betta fish images. However, we
were unable to find a significant difference between
the medium and large Betta fish images. This may
be due to the fact that an increase in aggression
levels in the male Betta fish can only increase to a
limit and quite possibly, the Betta fish show no
difference in the aggression towards both medium
and large images as both images are equal or bigger
than average Betta fish size. A difference in
aggression may also be seen if some of the male
Betta fish run a tendency of being low in aggression,
being less dominant than usual. This would lead it to
react slower to larger images due to the fact that it is
not as aggressive and dominant as other males.
The different levels of aggression by male Betta
fish is due to the male Betta fish showing superiority
in mating and in sexual selection if a female would
be present. (Doutrelanta et al, 2001). The different
degrees of aggression are due to the presence of
dominance and sub-dominance in Betta fish.
Aggression may also be based on the size of the
Betta fish, as Betta fish swell up and increase body
size to intimidate their opponent (Peake and
McGregor 2004).
However, aggression levels in Betta fish may not
be based on size alone. Betta fish subjected to
computer images shown with scale like patterns
showed more aggression than when subjected to
circular or contour like shapes (Bando, 1991),
meaning Betta fish react to changes in texture. Also,
the different color of the opponent male Betta fish
may also affect the aggression levels with the way
male Betta fish interact with each other (Sulindro &
Lam, 2005). This study examined the effect of the size
of images and Betta fish aggression which enabled an
understanding of the correlation between aggression
levels of Betta fish when confronted with larger or
smaller fish. Results showed that Betta fish are more
aggressive towards fish larger than the average size of
Betta fish, versus fish smaller than the average size.
Acknowledgements
We would like to acknowledge the support of
Saddleback College Biology department.
Literature Cited
Bando, Toshihiro. (1991) Visual perception of texture
in aggressive behavior of Betta splendens. J. of
Comparative Phys. 169(1):51-58.
Douglas, Kate. (2006)Evolution and us: some say it
has stopped, others believe it's going faster than ever.
So which is it? New Scientist 189 (2542): 30-33.
Doutrelanta, Claire. McGregora, Peter K. Oliveirab,
Rui F. (2001) The effect of an audience on intrasexual
communication in male Siamese fighting fish, Betta
splendens. Behavioral Ecology 12(3): 283-286.
Fantino, E. Weigele F, and Lancy D. (1972).
Aggressive display in the Siamese fighting fish.
Learning and Motivation. (3): 457-468.
Lam, T. Sulindro, A. (2005) Effect of color on latency
to aggressive display of the betta fish (Betta
splendens). Saddleback City College, unpublished
study.
Merrel, David J. (1949) Selective mating
Drosophila Melanogaster. Genetics 34: 370-389
in
Peake, Tom M. and McGregor, Peter K. Information
and aggression in fishes. (2004) Learning and
Behavior. 32(1): 114-121.
Setchell, Joanna M. Wickings, Jean. (2005)
Dominance, Status Signals and Coloration in Male
Mandrills (Mandrillus sphinx). Ethology.111 (1): 25
40
Saddleback Journal of Biology
Spring 2006
Absorbance of Cu2+ by yeast (Saccharomyces cerevisia)
Gregory Dickinson
Department of Biological Science
Saddleback College
Mission Viejo, CA 92692
Copper is an essential element in small doses, used in enzymes such as the
mitochondrial enzymes Cytochrome c oxidase, but it can become toxic as dosage increases.
Copper waste is a byproduct of the industrial world and must be treated. Some organisms
can tolerate higher concentrations of this metal ion, absorb it, and bind effectively
removing it from the environment. One such organism is the common yeast Sccharomyces
cerevisia which can absorb a significant amount of copper from solution (one tailed test of
t, p=1.33×10-7). An experimental group (n=10) consisting of copper, fructose, and yeast
was maintained in an incubator at 30±4°C along with a control group (n=5) of only copper
and fructose. Using a trendline produced by charting light absorbance versus Cu(NO3)2
concentration shows that the yeast actually absorbed 10.37% of the copper from solution.
The yeast effectively removes copper, however, due to their complex and delicate nature
their use appears limited in industrial applications.
Introduction
Organisms interact with their environment taking
in nutrients and expelling wastes. During the life
process, all organisms also absorb toxins such as
heavy metal ions, complex organic molecules, and
radioactive material that can act as an inhibitors or
poisons resulting in a variety of ailments and
possibly death. However, some materials, especially
heavy metal ions, are required in very small doses in
the biological process but become toxic in excess. In
today’s world economy many of these heavy metals
are produced as industrial byproducts polluting the
environment. Certain plants and fungi have adapted
to living in contaminated environments developing
survival mechanisms that isolate the effects of the
toxins usually by binding the toxins so they are no
longer in a harmful form. Soars et al. (2002) found a
leakage of inorganic phosphates from the cell when
Sccharomyces cerevisia was observed in a solution
containing the heavy metal cadmium.
These
phosphate molecules bound the cadmium and
prevented absorption by the yeast.
The first step in microorganism heavy metal ion
accumulation is to pass the cell membrane. Due to
its charged nature, a metal ion can not pass the cell
membrane without assistance, therefore, there must
be mechanisms for ion transport. Souza et al. (1997)
discovered one such mechanism while studying
hepatic cells and cadmium ions finding that the
cadmium ions were being absorbed through calcium
ion channels. Some organisms stop metal absorption
at the cell membrane. Mullen et al. (1989) found
Bacillus cereus, B. subtilis, Escherichia coli, and
Pseudomonas aeruginosa successfully absorbed a
variety of metals from solution, including Ag+, Cd2+,
and La3+, with varying levels of efficiency and most
of the metal ions were found bound in the cell
membrane. However, Strandberg et al. (1981) also
worked with Pseudomonas aeruginosa and uranium
absorbance and found the metal ions throughout the
cell, not just in the membrane. In this experiment
common baker’s yeast, S. cerevisia, will be observed
when added to Cu2+ and fructose. The fructose will
be consumed into energy, carbon dioxide, and
ethanol and a significant amount of the copper ions
should be absorbed by the yeast and effectively
removed from the solution.
Material and Methods
In order to ensure a 0.010 M solution of Cu(NO3)2
in the control and experimental groups two different
solutions with two different concentrations had to be
mixed. The experiment solution was a 0.014 M
solution of Cu(NO3)2 (Spectrum Chemical
Manufacturing, Inc. Gardena, CA) and the control
solution had a concentration of 0.011 M. A 40% (by
mass) fructose solution was prepared (Spectrum
Chemical Manufacturing, Inc. Gardena, CA).
Finally, a yeast solution was mixed by adding three
seven gram packets of yeast (Fleishmann’s ‘Active
Dry’ Yeast, Burns Philip Food Inc, San Francisco,
CA) to 300.0 ml of deionized water. For the
41
Saddleback Journal of Biology
Spring 2006
experimental group, 70.0 ml of 0.014 M Cu(NO3)2
solution, 20.0 ml of the yeast solution and 10.0 ml of
the fructose solution was measured into 10 clean and
dry erlenmeyer flasks with stirring bars. The
following equation ensuring a 0.010 M Cu(NO3)2
solution for the experimental group.
M1V1 = M2V2
M2 = M1V1/ V2
M2= 0.014 M Cu(NO3)2 × 70.0 ml / 100 ml
M2 = 0.010 M Cu(NO3)2
For the control group 90 ml of 0.011 M Cu(NO3)2
solution and 10 ml of the fructose solution was added
to five clean and dry erlenmeyer flaks with stirring
bars. This produced 100 ml of the 0.010 M
Cu(NO3)2 in both the control and the experimental
group. The following equation ensuring a 0.010 M
Cu(NO3)2 solution for the control group.
M1V1 = M2V2
V2 = M1V1/ V2
M2= 0.011 M Cu(NO3)2 × 90.0 ml / 100 ml
M2 = 0.010 M Cu(NO3)2
All 15 samples also had latex balloons (Unique
Industries, Inc. Philadelphia, PA) placed over their
tops to allow an expansion volume for both water
vapor and CO2 production. They were put into an
incubator (Revco Thermo Electron Corp, Model #
RI-12-555-ARA, , Asheville, NC) with a preset
temperature of 30±4°C and each flask was placed on
a magnetic stir plate (Nuovo Thermalyne stirplate,
Dubuque, IA) and set to stir at 140 revolutions per
minute (stir setting 4).
The flasks stirred
continuously for 62 hours, any longer would
compromise the latex balloons’ integrity.
A trend line relating light absorption at 610 nm
versus Cu(NO3)2 concentration was developed using
a
Du
520
General
Purpose
UV/VIS
Spectrophotometer (Beckman Coulter, Inc. Fullerton,
CA). The maximum absorbance wavelength, 610
nm, was found experimentally. Ten drops of 6M
NH4OH (Spectrum Chemical Manufacturing, Inc.
Gardena, CA) was added to 10 ml of 0.010 M
Cu(NO3)2 standard solution. This created a uniform
color in the Cu(NO3)2 solution per the following
reaction
(C
McLendon,
PhD.,
personal
communication, 10 April 2006) :
Cu2+(aq) + 4NH3 (aq) → Cu(NH3)42+(aq)
Ten drops of the 6M NH4OH produces an excess of
NH3+ ions ensuring all the free Cu2+ ions were
modified into Cu(NH3)4.
After the maximum
absorbance wavelength was determined the trendline
was found using Cu(NO3)2 standards of 0.0050,
0.0070, 0.0080, 0.0085, 0.0090, 0.010, 0.012
Molarity where 10.0 ml of solution had 10 drops of
NH4OH added to each (Figure 1).
The analysis of these samples produced a trendline
with an R-squared value of 0.995 and an equation
relating absorbance to molarity:
(a) absorbance = 54.67molarity - 0.0455
Rearranged, a solutions molarity can be determined
from its absorbance:
(b) molarity = (absorbance + 0.0455)/ 54.67
The experiment was completed at 62 hours when
the solutions were moved from the incubator into a
cooling refrigerator (Revco Thermo Electron Corp,
Model # RCRF252A14; Asheville, NC) set at 4°C to
slow or stop the yeast reaction. A yeast sample was
removed from one sample and analyzed under a light
microscope (Nikon Eclipse E20 with Nikon E Plan
100X oil emersion lens ;Tokyo, Japan) and then
digitally imaged (Nikon Eclipse E20 with Nikon E
Plan 100X oil emersion lens (Tokyo Japan),
MicroVid Image Capture System (Huntington Beach,
CA) attached to a Micron client pro computer
(Model # D845HV-0DY, Boise ID). At this time,
75.0 ml of each solution were filtered through #40,
11.0 cm ashless filter paper (Whatman plc;
Brentford, United Kingdom) and then #42, 11.0 cm
ashless filter paper (Whatman plc; Brentford, United
Kingdom) to remove the yeast. 10.0 ml of each
solution was taken from each sample and to each
10.0 ml sample 10 drops of 6 M NH4OH was added
to create complex ions, making them all the same
color.
Each sample was run through the
spectrophotometer at 610 nm and the absorbance was
measured.
These data were analyzed using
Microsoft Excel (Microsoft Corporation, Redmond,
WA).
Results
When inspected under a light microscope the
yeast from the experimental group had developed a
distinct blue color from the absorbance of the Cu2+
ions (Figure 2).
42
Saddleback Journal of Biology
Spring 2006
However, this metabolic requirement for copper is
very small, and the amount actually removed from
solution is statistically significant, supporting the
hypothesis that S. cerevisia would absorb Cu2+ ions
out of solution during the growth process. This
coincides with other research showing that many
other organisms, both large and small, absorb heavy
metals such as members of the genus Sargassum, a
common sea weed, that can effectively remove
chromium (Cossisch et al. 2002) absorbing as much
as 60% of the chromium out of solution.
There are a variety of methods to bind
copper ions in solution and all of these ways are
more robust compared to the delicate conditions
required by yeast. NaOH will bind copper ions and
produce an insoluble white precipitate. Also, the
process of electrolysis could produce a solid
elemental form of the metal.
0.500
0.490
Further analysis, using the spectrophotometer,
showed the absorbance (610 nm) for the experiment
group (n = 10; x = 0.436, S.D. =.0.00463) was
significantly lower than the absorbance for the
control group (n = 5; x = 0.492, S.D. = 0.00563 )
analyzed with a one tailed test of t at a 95%
confidence interval (p=1.33×10-7) (Figure 3).
Using equation (b), the average molarity for the
control and experimental groups can be determined.
The control groups’ average molarity was 0.009828
M and the molarity of the experimental group was
0.008809 M showing a 10.37% reduction in Cu2+
ions in the experimental group.
Discussion
Observing the Sccharomyces cerevisia under a
light microscope showed a deep blue color
throughout the yeast. However, it is not clear if this
color is maintained in the cell membrane or if the
copper had saturated the cell. Mullen et al. (1989)
found that other heavy metal ions were bound in the
cell membrane of other microorganisms but
Strandberg et al. (1981) found that uranium ions
were found throughout the cell in Pseudomonas
aeruginosa.
S. cerevisia was expected to remove some copper
ions out of solution because the copper is essential to
life. For instance, two copper ions are used in the
mitochondrial enzyme, Cytochrome c oxidase.
0.480
Absorbance at 610 nm
Figure 2.
Sccharomyces cerevisia at 1000x
magnification with a light microscope. The yeast
cells are blue due to absorbing Cu2+ ions.
y = 54.67x - 0.0455
R2 = 0.9945
0.470
Experim etnal group
(n=10) of copper, sugar,
and yeast solution
0.460
Control group (n=5) of
copper and sugar
solution
0.450
Linear (Absorbance
versus m olarity
trendline for copper
solution)
0.440
0.430
0.420
0.009
0.009
0.010
0.010
0.011
Cu(NO3) 2 concentration (Molarity)
Figure 3. Mean absorbance versus Cu(NO 3 ) 2 concentration for a
control group (n=5) of 0.010 M Cu(NO 3 ) 2 and sugar solution and an
experimental group (n=10) of Cu(NO 3 ) 2 , sugar and yeast solution
after 62 hours of incubation at 30 ±4° C. There is a significant
difference between the experimental and control groups' molar
concentrations using a one tailed t test (p <0.05). Average absorbance
shown with 95.0% confidence interval bars.
Literature Cited
Cossich E, Tavares C, Ravagnani T. 2002.
Biosorption of chromium(III) by Sargassum sp.
Biomass. Electronic Journal of Biotechnology (5) 2.
Mullen M, Wolf D, Ferris F, Beveridge T, Flemming
C, Bailey G. 1989. Bacterial sorption of heavy
43
Saddleback Journal of Biology
Spring 2006
metals.
Applied
55(12):3143-3149.
Environmental
Microbiology
Soars E, Duarte A, Boaventura R, Soares H. 2002.
Viability and release of complexing compounds
during accumulation of heavy metals by a brewer's
yeast.
Applid Microbiology & Biotechnology
58(6):836-41.
Souza V, Bucio L, Gutierrez-Ruiz M. 1997.
Cadmium uptake by a human hepatic cell line.
Toxicology 120:215-220.
Strandberg G, Shumate S, Parrott J. 1981. Microbial
Cells as Biosorbents for Heavy Metals:
Accumulation of Uranium by Saccharomyces
cerevisiae and Applied
Microbiology &
Biotechnology. 2002; 58(6):836-41 (ISSN: 01757598)
The Effects of Bicarbonate, Glucose, and Caffeine on Output Volume and pH of Urine
Kelley Siegert
Department of Physical Therapy
Saddleback College
Mission Viejo, CA 92692
The kidney is a highly specialized organ that helps the body maintain homeostasis by
selectively excreting or retaining certain substances depending on bodily needs. This study
seeked to observe renal function by recording the effects of four different solutions on urine
output and pH. Six human subjects drank plain water, bicarbonate, glucose, or caffeinated
coffee and then recorded their urine output and pH in the following two-hour period. The
volume of urine output and pH depends largely on whether or not the kidneys reabsorb the
ingested substances. It was predicted that water would not affect urine output or pH, while
bicarbonate and glucose would cause urine output to decrease and may cause pH to
increase slightly. Coffee would most likely not affect the pH level substantially, but would
cause the largest increase in urine output. Experimental results were consistent with
predicted hypotheses. None of the four substances consumed caused any significant change
(neither increase or decrease) in pH levels. After the first 40 minutes, all four substances
showed an increase in urine output, coffee being the largest increase and bicarbonate being
the smallest increase. After 80 minutes had passed, only coffee continued to increase urine
output, while all other three substances began, and continued to, decrease urine output in
the remaining trials. In the final 120-minute recording, coffee finally decreased in urine
output, but was still a significantly higher volume than the other three substances. As each
substance was treated differently by the kidney, and since certain substances are retained
more than others, the four substances had varying effects on the volume of urine output
recorded. Data tests were conducted using an ANOVA test for multiple variances for both
volume and pH values. For volume, coffee yielded a p-value of 0.0058, while water,
bicarbonate, and glucose demonstrated p-values of .0754, .0982, and 0.0860, respectively.
As the critical alpha value was 0.05, only coffee demonstrated a significant increase in urine
output. For pH, all substances yielded p-values larger than 0.05, indicating that no
significant change occurred in pH values in this study.
Introduction
This experiment examines the concept of renal
function, and its control of volume and pH of urine
output. The kidney is the body’s primary center for
reabsorption and filtration, and it controls most
aspects of renal function. The kidneys regulate
44
Saddleback Journal of Biology
Spring 2006
volume and composition of the body’s extracellular
fluids by balancing water volume, electrolytes, and
acid base concentrations (Rodwell et al, 2004).
Depending on the body’s physiologic needs, the
kidneys either excrete or reabsorb certain substances.
Reabsorption of valuable nutrients and water
and filtration of waste is largely dictated by the
nephron, the functional unit of the kidney. Each
kidney contains approximately one million nephrons,
which are responsible for reabsorbing 95 to 99% of
all water and fluids that we ingest (Martin et al,
2005). The kidneys also regulate blood osmolarity,
excrete waste, and produce hormones. Each of the
kidney’s one million nephrons perform five
fundamental processes: filtration, reabsorption,
secretion, osmotic exchange, and excretion
(Tokunaga et al, 2006).
Each nephron consists of a glomerulus
surrounded by a thin-walled structure called
Bowman’s capsule. This is where most of the
filtration occurs (DiBona and Kopp, 1997). The
proximal tubule is responsible for most of the
reabsorption. Glucose, amino acids, and about 80%
of salt and water are reabsorbed here by active
transport mechanisms (DiBona and Kopp, 1997). The
loop of Henle and the collecting duct reabsorb most
of the remaining filtered salt and water. The distal
tubule reabsorbs sodium and a few other varied
substances.
The aim of this project is to observe the effects
of bicarbonate, glucose, and caffeine on renal
function. Elements of renal functioning to be
measured include volume of urine output and pH
level. Subjects will consume one of four
predetermined substances containing a certain
percentage of bicarbonate, glucose, caffeine, or plain
water to serve as a control. Solutions containing
coffee should cause an increase in the volume of
urine output. Solutions containing glucose or
bicarbonate should not cause a significant change in
urine output, but may decrease the volume slightly.
All solutions will most likely cause only slight
changes, if any, in levels of pH (Rosner and Bolton,
2006). Studying this information will be valuable to
many scientific industries. It will help form the
foundations for better diets to enhance optimal renal
functioning, allow us to develop medicines for those
who suffer from diseases of the kidney, and help us
come to a better understanding of overall renal
function.
Methods and Materials
Six subjects consumed 500 ml of a
predetermined solution on four different dates. In
order to avoid extraneous factors of human
variability, the same six subjects ingested all four of
the solutions, drinking one solution on each of the
four dates. The four solutions being used were A)
Kirkland bottled water, B) 10% bicarbonate Kirkland
bottled water, C) 10% glucose Kirkland bottled
water, and D) Folgers caffeinated coffee.
Experiments were conducted on Sunday afternoons
over a four-week period. On each Sunday, trials
began at approximately 3:00 PM. Prior to the
experiments, subjects consumed a similar diet of food
and liquid intake consisting of a breakfast of cereal
with milk and orange juice, and a lunch of a
sandwich, chips/salad/ or fruit, and milk/juice, or
uncaffeinated soda. While subjects did consume a
similar diet, individual variations in amounts and/or
types of foods ingested may have existed.
At the onset of the experiment, subjects were
asked to void their bladder. Following this, subjects
consumed 500 ml of the solution for that date.
Subjects continued to drink 100 ml of this solution at
20-minute intervals for the next two hours. Movie
entertainment was provided to ensure that subjects
engaged in similar activities during the two-hour
period. Subjects were asked to urinate after 40
minutes, 80 minutes, and 120 minutes. During each
of the three attempts, subjects measured the volume
of their urine output using a graduated cylinder.
Using a small pipette, subjects transferred five ml of
urine into a centrifuge tube. This sample was tested
for pH level using a Baker-pH IX pH stick.
Results
In regards to volume of urine output, all four
substances caused an increase in urine output forty
minutes following the initial void. Water and coffee
increased more substantially than bicarbonate or
glucose. At eighty minutes following the initial void,
only coffee had continued to increase. The three other
substances decreased during this trial, and would
continue to decrease in the last measurement. In the
last trial, the volume of urine output for coffee finally
decreased, but to an average value still significantly
higher than the other three substances.
The collected data for volume of urine output
was tested using an ANOVA test with multiple
variances. For this study, a critical alpha value of .05
was set, meaning that only results demonstrating a pvalue of less than .05 could be attributed to
experimental variables. While subjects having drank
bicarbonate and glucose did decrease their urine
output, it was not a significant enough change to
support our hypothesis. The p-value for bicarbonate
was .0982, while glucose yielded p= 0.0860. As both
of these values are larger than .05, we cannot
attribute the slight decrease in urine output to these
experimental variables. Results for subjects having
consumed coffee were more significant. Coffee
45
Saddleback Journal of Biology
Spring 2006
demonstrated a p-value of .0058, indicating that the
substantial increase in urine output was a result of
consumption of coffee.
pH values demonstrated less variation than did
urine output. While individual variation seemed to
have existed in each of the trials, the averaged pH
values changed by .40 or less. pH values showed no
trends towards an apparent increase or decrease, and
no substance changed more significantly than the
others. In the scope of the pH scale, which ranges
from 0, (very acidic) to 14, (very basic), a change of
.40 is not substantial enough to contribute to
experimental factors. An ANOVA test with multiple
variances was also conducted for average pH values.
Water, bicarbonate, glucose, and coffee demonstrated
p-values of .198, .286, .269, and .286, respectively.
As all of these p-values are substantially larger than
the critical value of .05, it can be confidently
concluded that any slight changes in pH values
observed in this study were not due to experimental
variables.
Table 1. Average volumes of urine outputs for all four ingested substances over a two-hour period
Average Volumes (ml)
Substance
Water
Bicarbonate
Glucose
Coffee
0
163
145
149
137
40
225
188
195
234
80
170
174
155
280
120
91
109
107
167
300
250
Volume (ml)
200
Water
Bicarbonate
150
Glucose
Coffee
100
50
0
0
40
80
120
Time (Minutes)
Figure 1. Average volumes of urine outputs for subjects consuming all four substances over a two-hour period. The
p-value for coffee was .0058, making it the only substance to cause a significant change in volume of urine output.
All three other substances demonstrated p-values larger than0 .05.
46
Saddleback Journal of Biology
Spring 2006
Table 2. Average pH levels of urine outputs for all four ingested substances over a two-hour period.
Average pH
Substance
Water
Bicarbonate
Glucose
Coffee
0
6.67
6.92
6.75
7.08
40
6.92
7
6.92
7.33
80
7.08
7.17
6.92
7.25
120
7
7.08
7.08
7
7. 4
7. 2
7
Wat er
B ci ar bonat e
6. 8
Glu cose
Cof f ee
6. 6
6. 4
6. 2
0
40
80
120
Tm
i e (m in u t e s )
Figure 2. Average pH levels of urine outputs for subjects consuming all four substances over a two-hour period.
Values demonstrated little change during the two-hour period, varying by only .5 or less. All four substances yielded
p-values larger than .05, indicating that none caused a significant change in pH level.
Discussion
Some of our initial predictions were supported
by our data. All four substances exhibited an
increase in urine output following the initial clearing
of the bladder. Subjects having ingested coffee and
plain water demonstrated the largest rises, increasing
by averages of 62 ml and 97 ml, respectively. This
result is not surprising for coffee, whose quality as a
diuretic is widely known. The reasoning for water,
however, is less obvious. Possibly, since plain water
(especially bottled) contains less nutrients to be
reabsorbed, a larger initial volume of it is excreted
out of the kidneys to be removed from the body.
This accounts for the large initial volume seen in our
experiment.
While all four substances demonstrated an
increase in the first trial after 40 minutes, only
subjects having ingested coffee continued to
increase their volumes of urine output following this
point. These results are similar to those in a study
conducted by Tokunaga et al, 2006, who found that
urine output increased in rats treated with stimulants.
Subjects having consumed plain water, bicarbonate
water, or glucose water demonstrated a progressive
decrease in volumes of urine outputs after the 40
minute-trial. Plain water decreased from an average of
225 ml to 170 ml, bicarbonate water decreased from
an average of 188 ml to 174 ml, and glucose water
decreased from an average of 195 ml to 155 ml (Table
1). As both glucose and bicarbonate demonstrated a
substantial decrease in urine output, we can reason
that these are substances the kidney reabsorbs more of
than others. This is most likely because bicarbonate
and glucose provide the body with more essential
nutrients than either plain water or coffee. All three
substances continued to exhibit decline in the 120minute trial. After the 40-minute trial, subjects
consuming coffee continued to increase from an
average of 234 ml to 280 ml. Solutions containing
caffeine should increase the volume of urine output
based on caffeine’s quality as a diuretic (Buyukdereli
et al, 2005). Following this trial, averages for subjects
consuming coffee finally decreased to a volume of
167 ml, a final value still significantly higher than
those of the other three substances. Coffee yielded a pvalue of .0058, meaning that results for coffee
47
Saddleback Journal of Biology
Spring 2006
supported our initial hypothesis. Water demonstrated
a p-value of .0754, a value larger than the critical
alpha of .05. As it had been predicted that water
would not cause any significant change in urine
output, this data also supports our initial hypothesis.
Figure 2 shows the average pH levels of urine for
subjects consuming all four substances over the twohour period. Although this graph does seemingly
show substantial variation, changes in pH in this
experiment proved to be insignificant. Values
changed by 0.4 or less. Martin et al also found that
substances containing bicarbonate acted as a buffer
in preventing urine pH changes in their study of
renal function testing in humans (Martin et al, 2005).
In relation to the pH scale, which ranges from 0 to
14, a change this small is too insignificant to
attribute to experimental variables. These results are
consistent with studies peformed by Rosner and
Bolton (2006), which found that little variation
existed in pH of human urine. Initial predictions
were that water and coffee would cause no change in
pH, while bicarbonate and glucose would cause pH
to increase. Thus, initial hypothesis for water and
coffee were supported by these results.
After learning more about the kidney and what it
reabsorbs, we know now this is most likely because
the kidney reabsorbs virtually 100% of glucose and
bicarbonate. Glucose provides the body with
essential nutrients, in addition to fueling some of the
body’s physiologic processes. Bicarbonate acts as a
buffer for the body and helps to maintain the pH
balance. The bicarbonate that was reabsorbed helps
the body resist changes in pH levels. This helps
explain why no significant change in pH was
observed.
In conclusion, coffee was the only substance
believed to cause a significant increase in volume of
urine output over time. This result was somewhat
expected, given coffee’s quality as a diuretic. While
water, bicarbonate, and glucose actually seemed to
decrease volume of urine output over time, the change
was not significant enough to attribute to experimental
variables. None of the four substances caused any type
of significant change in pH levels of the urine.
Literature Cited
Buyukdereli, G., Guney, I.B., Seydaoglu, G. 2005.
Effectiveness of Diuretic Injection on the
Measurement of Differential Renal Function Using
Tc-99m DMSA in Patients With a Dilated Renal
Pelvis. Clinical Nuclear Medicine, 30(11): 721-724.
DiBona, G.F. and Kopp, U.C. 1997. Neural Control of
Renal Function. Physiological Reviews, Volume 77,
75-97.
Martin, W., Armstrong, L., Rodriguez, N. 2005.
Dietary Protein Intake and Renal Function. Nutrition
and Metabolism, 27(3): 122-129.
Rodwell, G., Sonu, R., Zahn, J., Lund, J., Wilhelmy,
J., Wang, L., Xiao, W., Mindrinos, M., Crane, E.,
Segal, E., Myers, B., Brocks, J., Davis, R., Davis, R.,
Higgins, J., Owen, A., Kim, S. 2004. A
Transcriptional Profile of Aging in the Human
Kidney. Public Library of Science, Volume 2(12): 5682.
Rosner, M. and Bolton, W. 2006. Renal Function
Testing. American Journal of Kidney Disease, 12(9):
85-97.
Tokunaga, I., Kubo, S., Ishigami, A., Gotohda, T.,
Kitamura, O. (2006). Changes in Renal Function and
Oxidative Damage in Methamphetamine-Treated Rat.
Legal
Medicine
(Tokyo),
58(7)
46-61.
48
Saddleback Journal of Biology
Spring 2006
The Effects of Light Wavelength on Seed Germination and Plant Growth
Christine Knappe
Department of Biological Sciences
Saddleback College
Mission Viejo, CA 92692
Seed germination, plant development, and growth are regulated by light waves, mostly
from the visible light spectrum. Under normal conditions, light waves from the red end of
the visible light spectrum promote seed germination, and light waves from the blue end are
responsible for photochemical reactions such as photosynthesis, which in turn regulates
growth. During this experiment, the effect of light on seed germination and plant growth
of Phaseolus vulgaris was monitored. The percentage of seed germination was monitored
daily for a period of two weeks, and the growth of each sprout was measured weekly for
three consecutive weeks. Two control groups were studied; one using a fluorescent light
bulb and filter to simulate the ultraviolet to blue light spectrum and another using an
incandescent light bulb and filters to simulate the red to infrared light spectrum. The
results showed a significant difference in the percentage of germination between the
spectrums, yet no significant difference in the average overall height of each group of
plants existed.
Introduction
The visible light spectrum is a small part of a
full spectrum known as the electromagnetic
spectrum. The numbers of wave crests that pass
through a given point in a given amount of time are
measured as frequencies.
Wavelengths vary
inversely to frequency, with the highest frequency of
radiation having the shortest wavelength. Colors
differentiate the various frequencies. The colors in
the visible light spectrum range from violet, the
shortest wavelength, to red, the longest wavelength.
Wavelengths are measured in Angstrom units (Å)
which is equivalent to 1 x 10-10 meter. Fluorescent
and incandescent light bulbs produce light that most
similarly resembles the quality of light produced by
the sun. The fluorescent bulbs have less energy in
the higher wavelengths, 6500 Å and above, and the
incandescent bulbs have less energy in the
wavelengths below 5500 Å (Abraham, 1965).
According to Borthwick (1957), the red
wavelength band, which ranges from 5500 to 7000
Å, is mainly responsible for a wide range of
unrelated functions in plants and trees, specifically
seed germination and formation of particular
pigments, but the benefits from the red light is
reversed by subsequent exposure to far red
wavelengths of light. Borthwick considered far red
wavelengths to be above 7000 Å (1957). Similarly,
another study indicated that red light promoted
germination, and far red light inhibited germination
(Hazebroek 1990).
On the other hand, a
photosynthesis laboratory experiment utilizing a
spectrophotometer to perform chlorophyll extraction
tests on a spinach leaf determined that blue and violet
wavelengths were the primary wavelengths utilized
most for photosynthesis in green plants (Teh, 2006).
Also, blue light triggers processes such as the opening
and closing of the stomata and phototropism (Stoelzle,
2003).
Wavelengths of light can be simulated using
fluorescent and incandescent light bulbs with filters to
remove the undesired wavelengths.
Dark blue
cellophane does not transmit very much light between
5575 Å and 6575 Å, therefore, a daylight fluorescent
bulb plus a blue filter will allow light waves of 39005500 Å to pass through, simulating light within the
violet and blue spectrum. Similarly, a 150-watt
incandescent bulb plus a red and a blue filter will
allow light waves of 7000 Å and up to pass through,
simulating red to infrared light (Abraham, 1965).
Tendergreen Bush Beans are a variety of the dry
bean Phaseolus vulgaris L, a mild-flavored green bean
and a member of the pea family. These bean plants
grow ideally in temperatures between 33° and 43°C
(Stephens, 1994). The goal of this experiment was to
determine which end of the visible light spectrum was
more influential in the germination and growth of
Phaseolus vulgaris L. The expectations are that if all
oxygen, soil, water, and temperature conditions are
ideal and consistent, then the seeds exposed to the
blue wavelengths of light will germinate and grow
49
Saddleback Journal of Biology
Spring 2006
Materials and Methods
Three packages of Lilly Miller brand seeds
containing a total of two hundred sixteen
Tendergreen Bush Bean (Phaseolus vulgaris) seeds
were purchased from Armstrong Garden Center in
Lake Forest, California. They were planted in two
mini-greenhouse seed starters on March 19, 2006 in
Coto de Caza, California. In one greenhouse, two
seeds were planted in each compartment numbered
one through forty-eight, and one seed was planted in
each compartment numbered forty-nine through
sixty. In the other greenhouse, the seeds were
planted using the same method. The seeds were
planted 2 cm beneath the surface of 30 ml of
Schultz® Seed Starter Potting & Planting Mix
Plus™ with Schultz® slow release MultiCote®
plant food. Each compartment was watered with 25
ml of water. The greenhouse lids were snapped into
place on the trays. One tray was covered with one
sheet of blue cellophane to simulate ultraviolet to
blue light and placed under an 80 watt daylight
fluorescent bulb. The other tray was covered with
one sheet each of red and blue cellophane, with the
blue cellophane on top to simulate red to infrared
light then placed under a 150 watt incandescent light
bulb. Neither greenhouse was directly affected by
other sources of light. Each greenhouse was the
same distance from each light source.
The
environments’ temperatures ranged from 38° to
41°C.
During the first week, two greenhouses were
constructed. Each greenhouse was 91.37 cm wide
by 152.28 cm long by 91.37 cm high. One
greenhouse was covered with two layers of blue
cellophane and placed under the 80 watt fluorescent
light and the other greenhouse was covered with one
sheet of red cellophane with another sheet of blue
cellophane on top and placed under the 150 watt
incandescent light. The cellophane and lids were
then removed from the mini-greenhouses. One
week after each seed sprouted, the sprouts were
transplanted to individual small peat pots measuring
6 cm high with a base of 4 cm and an opening of 6
cm at the top. The planting medium used was 59.1
ml of Schultz® Professional Potting Soil Plus™
with Schultz® slow release MultiCote® plant food,
and 3 cm of the stem, from the roots, were placed
below the dirt. Each pot was returned to the
respective greenhouse. The sprouts were watered
every fourth day with 10 ml of water. After fourteen
days from the original day of sprouting, the sprouts
were transplanted to a peat pot measuring 8.5 cm
high with a base of 5 cm and an opening of 8 cm at the
top in 177 ml of the same potting soil used in the
previous transplant with 4 cm of the stem planted
below the dirt. The pot was placed back under the
proper greenhouse. After the second transplant, the
plants were watered every fifth day with 25 ml of
water until April 9, 2006. Germination in the minigreenhouse was monitored daily. The height of each
sprout was measured every seventh day after the
initial planting. The height was measured from the
dirt to the base of the highest leaf, including how
many centimeters of plant was below dirt level.
Results
The simulated light in the red to infrared
spectrum caused 26 seeds to germinate during week
one, the equivalent of 24.07%, and six additional
seeds germinated during week two, 5.56 %. The total
number of seeds germinated was 32. Therefore
29.63% of the original 108 seeds germinated while
under the artificial red to infrared light spectrum.
Three weeks after the initial planting, the tallest plant
in the red to infrared spectrum was 50 cm and the
shortest was 28 cm. The mean height of these plants
was 39.8 cm. The average absolute deviation from the
median was 6.47 cm.
The light simulated as the ultraviolet to blue
spectrum germinated a total of fifteen seeds. The
majority of those seeds, thirteen, germinated during
week one, for a figure of 12.04%. During the second
week, only two seeds germinated, 1.85% of the total
seeds planted. The tallest plant was 47 cm and the
shortest was 21 cm. The mean height of these plants
three weeks after the initial planting was 35 cm. The
average absolute deviation from median was 9.44 cm.
The red spectrum plants had an overall 15.74
higher percentage of germination than the blue
spectrum plants (Chi-square analysis p = 0.001). The
red spectrum plants also grew taller than the blue
spectrum plants by an average height of 6.19 cm
(unpaired t-test, p= 0.197).
45
Mean Height after 3 weeks (cm)
faster than the seeds exposed to the red to infrared
wavelengths of light.
40
35
30
25
20
15
10
5
0
Red Light
Blue Light
Simulated Light Spectrum
Figure 1. Plant under Red light grew much taller plants
under Blue light.
50
Saddleback Journal of Biology
Spring 2006
Red Light
35
Percent Germinated
30
25
20
15
10
Blue Light
5
0
1
2
3
Week
wavelengths. He also suggested using two layers of
red and two layers of blue cellophane to simulate a
pure form of far red light. Since only one layer of
each of red and blue cellophane were used, the seeds
and plants were exposed to wavelengths of light in the
red spectrum at the same time as the far red and
infrared spectrum. The next logical progression for
further study would be to simulate a pure red light
spectrum control group and a pure far red to infrared
light spectrum control group to determine which end
of the red spectrum is more beneficial for germination
and growth of Phaseolus vulgaris.
Figure 2. Seeds under Red light germinated more
than those under Blue light (p = 0.001).
Discussion
This experiment indicates that the red light
spectrum is more influential to the germination of
the seed. The blue light spectrum did not produce as
many plants as expected. Based on the chi-square
results, a significant difference exists between the
two groups, based on how many seeds were planted
compared to how many germinated. Although less
than half of the blue light spectrum seed group
germinated compared to the red light spectrum
group, the probability of the result of an unpaired ttest was greater than 0.05, showing no significant
difference existed in the average height reached after
three weeks of the initial planting; therefore, no
substantial difference existed as to which light
wavelength a plant needs for growth to take place.
Since no chlorophyll extract tests were performed,
no determination can be made as to whether one
light spectrum affected the rate of photosynthesis
significantly more than the other. Although the
number of leaves on each plant was not recorded, no
significant difference was apparent.
Borthwick (1957) concluded that reversal of
germination and other processes took place by
exposure to far red light after exposure to red light
Literature Cited
Abraham, N., Balch, P., Borron, D. E., Erk, F. C.,
Kastrinos, W., Lightner, J. P. (1965). Biological
Science: Interaction of Experiments and Ideas. New
Jersey: Prentice-Hall.
Borthwick, H.A. (1957). Light Effects on Tree
Growth and Seed Germination. The Ohio Journal of
Science. 57(6): 357-364.
Hazebroek, J.P., Metzger, J.D. (1990). Environmental
control of seed germination in Thlaspi arvense
(Cruciferae). The American Journal of Botany. 77(7):
945-953.
Stephens, J.M. (1994). Bean, Dry – Phaseolus
vulgaris L. University of Florida, IFAS Extension.
HS551.
Stoelzle, S., Kagawa, T., Wada, M., Hedrich, R.,
Dietrich, P. (2003). Blue light activates calciumpermeable channels in Arabidopsis mesophyll cells
via the phototropin signaling pathway. Proceedings of
the National Academy of Sciences of the United
States. 100(3): 1456-1461.
Teh, S. (2006). Biology 20 Laboratory. Saddleback
College, Mission Viejo, CA.
51
Saddleback Journal of Biology
Spring 2006
Effect of Temperature on Lactic Acid Fermentation in Yogurt
Maona Yui
Department of Biological Science
Saddleback College
Mission Viejo, CA 92692
Fermentation is the anaerobic metabolism which occurs in absence of oxygen. In this
experiment, after 24 hours of incubation in different temperatures (22°C and 37°C,) the
amounts of products of lactic acid fermentation in yogurt were measured. The hypothesis
was that in 37°C, fermentation occurred efficiently. The result showed that the hypothesis
was valid, and the fermentation tubes in 37°C had a greater amount of product of
fermentation than in 22°C.
is produced due to fermentation. It showed that
fermentation occurred both in the tubes placed in 37C
temperature and the tubes kept at room temperature.
There were differences in the amount of whey
produced in fermentation between in the tubes kept at
37C (0.6±0.49ml) and the tubes kept at room
temperature (0.25±0.22ml). The tubes at 37C had a
higher amount of fermentation activity (t-test p=0.03)
than the tubes at room temperature (Figure 1).
0.7
Am o u n t o f w hey pro du ced (m L )
Introduction
Cellular respiration and fermentation are two
important ways that a cell can convert food into
energy. As a first process, both start with glycolysis,
which is breaking down or splitting of glucose into
pyrubic acid. In fermentation, the next step occurs
without oxygen. These pyrubic acid molecules are
turned into some waste product, and a little energy is
produced. One common type of fermentation is
lactic acid fermentation. In this reaction, pyribic acid
molecules are turned into lactic acid. Lactic acid
fermentation is done by some fungi, some bacteria,
and sometimes by human bodies. There are optimum
temperatures for each fermentation (Zisu and Shah,
2003). The main aim of this experiment is to study
the effect of temperature for lactic acid fermentation
in yogurt. The hypothesis is that specific
temperature promotes efficient fermentation, and it
is expected that there will be a significant difference
in the amounts of product in 37C versus 22C.
0.6
0.5
0.4
0.3
0.2
0.1
0
22°C
37°C
Temperature (C)
Materials and Method
Twenty fermentation tubes were prepared.
Seventy ml of vitamin D milk and thirty ml of plain
yogurt were mixed in a 300ml beaker in ratio of 7:3.
The milk was boiled prior to the experiment so that
if there were any bacteria in the milk, they would
not affect the results of the fermentation. The 15ml
of mixed milk and yogurt was poured into each
fermentation tube. Ten of the fermentation tubes
were placed in the refrigerator which kept 37C
temperature and 10 fermentation tubes were kept at
room temperature, which was 22C. After 24 hours,
the products of the fermentation were measured.
Figure 1. After 24 hours of incubation, the 37°C
group produced more whey (p = 0.03)
Discussion
The differences of amount of whey indicated that
more fermentation occurred in 37C than 22C since
whey is the product of fermentation (Briczinski and
Roberts 2002). This result provides support for my
hypothesis. Temperature affects the rate of
fermentation, and there is an optimum temperature for
fermentation. This experiment benefits fermentation
products such as alcohol, yogurt, and cheese to be
produced efficiently.
Results
In almost all of the fermentation tubes, the layers of
clear liquid were visible on the surface of the white
mixed milk and yogurt. This liquid was whey, which
52
Saddleback Journal of Biology
Spring 2006
Literature Cited
Briczinski, E. P. and Roberts, R. F. (2002).
Production of an Exopolysaccharide-Containing
Whey Protein Concentrate by Fermentation of
Whey. J. Dairy Sci. 85:3189-3197
Zisu, B. and Shah, N.P. (2003). Effects of pH,
Temperature, Supplementation with Whey Protein
Concentrate, and Adjunct Cultures on the Production
of Exopolysaccharides by Streptococcus thermophilus
1275. J. Dairy Sci. 86:3405-3415
The Ability of Saddleback College Students to Recognize the Presence or Absence of
Caffeine in Diet Coke
Moriah Harris and Ladi Boustani
Department of Chemistry and Psychology
Saddleback College
Mission Viejo, CA 92692
Taste is determined by taste receptor cells in the tongue which are clustered in taste
buds. Caffeine is categorized in the bitterness section of the five taste sensations. An
amount of 45 mL of diet coke and caffeine free diet coke was distributed to 50 male and 50
female participants. It was hypothesized that the majority of participants would be able to
detect caffeine in their drinks. The majority of participants (69%) could not detect caffeine
in their drinks, (p=0.001). There was no difference between the ability of males and females
in detecting caffeine. Of the smoker participants, 77% could not detect caffeine. These
results could possibly suggest the negative effect of nicotine on smokers’ taste buds.
Introduction
Taste is determined by taste receptor cells in the
tongue which are clustered in taste buds. All five taste
sensations (sweet, sour, salty, bitter, umami) are
represented by a single taste bud which ranges from
50-100 taste cells (Anonymous, 2005). Taste intensity
varies according to the sensitivity level of an individual
(Prescott et al., 2001).
In a study by Gent and Bartoshuk, the relationship
between loudness (1000 Hz) and taste intensities was
tested. This study suggested that tasters and non-tasters
have a similar perception of loudness as they do taste
(Gent and Bartoshuk, 1983). They concluded that
certain compounds such as sucrose, neohesperidin,
dihydrochalcone, and saccharin are more intense to
tasters as opposed to non-tasters.
Another factor that can affect taste is thermal
stimulation. In Green and Georges’ study, they
associated thermal stimulation with the perception of
sweetness. They concluded that sweetness perception
was elevated with the increase of thermal stimulation.
Evidence was also reported of alternate sources that are
independent of taste stimulus, taste quality, or gustatory
nerve (Green and George, 2004).
Caffeine is categorized in the bitterness section of
the five taste sensations (Leach and Noble, 1986).
Caffeine obtained a greater maximum rate initially and
lesser rate of bitterness decay. In their research, Leach
and Noble discovered that the maximum intensity of
quinine solutions was higher in tasters than in nontasters. In the results of an alternate research project,
between the other compounds tested (caffeine,
denatonium benzoate, limonin, naringin, quinine and
sucrose octa-acetate), caffeine was not greatly affected
but it increased the bitterness in the other compounds
(Cubero and Castillo, 2001).
There are many factors that can influence taste.
The factor that we focused on was the effect of nicotine
in cigarettes on smokers’ taste buds. The goal of this
study is to see if people could detect caffeine in diet
coke vs. caffeine free diet coke. It was hypothesized
that the ability to taste caffeine would be different in
smokers (due to the nicotine in cigarettes) than in nonsmokers and that the majority of people would have the
ability to determine the presence of caffeine.
Materials and Methods
This project was based on the noticeable difference
between caffeine-free diet coke and regular diet coke.
The participants consisted of 50 male and 50 female
students (ages between 18-25 yrs.) from saddleback
college. Two bottles of diet coke and caffeine-free diet
coke and a 100 three ounce cups were purchased from
Pavilions and distributed to random volunteers at
53
Saddleback Journal of Biology
Spring 2006
40
35
# o f P a r t ic ip a n t s
Saddleback College. Out of those 100 cups, half of
them marked as letter A, and the other half marked as
letter B, in order to eliminate the main confounding
factor which is the effect of the participant’s
expectation on the ending result. Each volunteer picked
one of each cup (marked with letter A and B), and
drank them in the order of their choice. The
participants then completed a survey, asking whether
they thought if caffeine was present or not. At the end
the survey sheets (n=100) were reviewed and
calculated using chi squared tests.
30
25
Male
20
Female
15
10
5
0
Detector
Nondetector
Results
# o f P a r ti c i p a n ts
80
70
60
50
40
30
20
10
0
Figure 2. 70% of males and 68% of females could not
detect caffeine.
50
# o f P a rticipa nts
One hundred different individuals (50 male and 50
female) were given a 45 mL sample of both caffeinefree diet coke and regular diet coke. Of the 100
individuals sampled (Figure 1), 69% were not able to
determine the presence of caffeine (p=0.001). Of the
69%, there was no significant difference between
males (70%) and females’ (68%) ability to detect the
presence of caffeine (Table 1/Figure 2). Out of the 50
male participants, 46% were smokers and out of the 50
female participants, 16% were smokers (Figure 3).
Within the participants that could not detect caffeine,
29% of the males and 15% of females were smokers. In
comparing smokers to non-smokers 77% of smokers
could not detect caffeine, whereas 23% of non-smokers
could.
40
30
Smoker
20
Non-smoker
10
0
Detector
Nondetector
Figure 3. 77% of smokers could not detect caffeine.
Discussion
Detector
Nondetector
Figure 1. 69% of participants could not detect caffeine
(p=.001)
Table 1. Ability of Participants to Recognize the
Presence of Caffeine
Detector
Non-detector
Male
15
35
Female
16
34
The results of this experiment showed that there
was a significant difference between detectors and non
detectors. Although a majority of participants could not
detect caffeine, they could differentiate between the
two drinks.
Diet coke is sweetened with 0.1 g of aspartame.
Aspartame is an FDA approved drug that can cause
multiple side effects such as cancer, nausea, etc.
(Cohen, 1997). Aspartame is often used as a sugar
substitute for many food products. It is possible that
this drug may have masked the bitter taste of caffeine
in the diet coke. It is easier to differentiate between
caffeine and decaf single-handedly because of the bitter
taste of caffeine. If regular and decaf espresso shots
were substituted for diet coke, there would be a greater
chance that participants would be able to differentiate
between the two.
There was no significant difference between males
and females. Out of males, 70 % could not detect
caffeine and out of females, 68% could not detect
caffeine.
The nicotine in cigarettes did not affect the smoker
participants’ abilities to detect caffeine. Out of the
54
Saddleback Journal of Biology
Spring 2006
smokers, 77% could not detect the presence of
caffeine. Out of the non-smokers, 65% were not able to
detect the caffeine. There is a 12% difference between
smokers and non-smokers who could not detect the
caffeine (which is not significant). In a study done by
Simons, recognition of nicotine receptors can provide a
unique mechanism by which bitter chemicals (caffeine)
could activate taste cells of smokers (Simons, 2002).
It was assumed that there would be a significant
difference and that a majority of participants would be
able to determine the presence of caffeine in their
drinks. This study concluded that there was no
significant difference between males and females. In
general, the majority of all the participants (smokers,
nonsmokers, males and females) were not able to
detect the presence of caffeine.
Literatures Cited
Anonymous, 2005. The Sense of Taste.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages
/T/Taste.html.
Cohen, J. 1997. The Effects of Different Storage
Temperatures on the Taste and Chemical Compositions
of Diet Coke. Food Chemical News Vol. 39 #11.
Cubero, E., Castilo, A.C. 2001. Effect of Compound
Sequence on Bitterness Enhancement. Chemical
Senses. Vol.26 #4. 419-424.
Gent, J.F., Bartoshuk, L.M. 1983. Sweetness of
sucrose, neohesperidin dihydrochalcone, and saccharin
is related to genetic ability to taste the bitter substance
6-n-propylthiouracil. Chemical Senses. Vol. 7 #3-4.
265-272.
Green, B.G., George, P. 2004. ‘Thermal Taste’ Predicts
Higher Responsiveness to Chemical Taste and Flavor.
Chemical Senses. Vol.29 #7. 617-628.
Leach, E.J., Noble, A.C. 1986. Comparison of
bitterness of caffeine and quinine by a time – intensity
procedure. Chemical Senses. Vol. 11 #3. 339-345.
Prescott, J., Ripandelli, N., Wakeling, I. 2001. Binary
Taste Mixture Interactions in PROP Non-tasters,
Medium-tasters and Super-tasters. Oxford University
Press. Vol. 26 #8. 993-1003.
Simons, C. 2002. Effect of cigarette smoke and
nicotine on taste processing. University of California,
Davis.
The Effects of Sucrose, Aspartame and Sucralose on Fermentation in Yeast
(Saccharomyces cerevisiae)
Lori Sandoval
Department of Art History
Saddleback College
Mission Viejo, CA 92692
All organisms carry out glycolysis, the initial phase of cellular respiration, in which cells
extract energy from glucose. Although glucose is the source of energy for all cellular
respiration, how does the substitution of sugar with artificial sweeteners affect the
metabolic process of cellular respiration? In a nation obsessed with beauty and fitness,
“low fat” or “sugar free” products makeup everyday nutrition with some type of artificial
sweetener. By means of fermentation, the aim of this experiment was to determine the
metabolic difference, if any, between table sugar (sucrose) and the artificial sweeteners
Equal® (aspartame) and Splenda® (sucralose). It was hypothesized that sucrose would
metabolize a greater amount of carbon dioxide than both Equal and Splenda. Sugar
solutions were fermented for a period of 24hrs and carbon dioxide product was recorded
and tested by ANOVA. Gas products resulted in Splenda® with the greatest amount of
carbon dioxide with an average of 2.4ml followed by a mean of 1.075ml that was produced
by Equal®, while sucrose produced the lowest average amount of 0.64ml, therefore, not
supporting the hypothesis. However, data analysis revealed that there was a P value of
0.232, which indicates no statistical difference (P<0.050) between the three sugar groups.
55
Saddleback Journal of Biology
Spring 2006
In a nation obsessed with beauty and fitness, it
has become the norm to find hundreds of products
advertising “low fat” or “sugar free,” geared towards
consumers on the bandwagon of the current diet
craze. With various popular diet trends, grocery
shelves are filled with an assortment of products that
contain some type of artificial sweetener. Mainly
concerned with the amount of calories,
carbohydrates or fat, most consumers do not give the
ingredients a second thought nonetheless how these
ingredients affect the body. Needless to say, most
consumers are oblivious to cellular respiration and
to the metabolic function of nutrients in their
everyday diet.
Cellular respiration is the metabolic processes by
which cells produce energy through the oxidation of
nutrient molecules.
All organisms carry out
glycolysis, the initial phase of cellular respiration, in
which cells extract energy from glucose. The
glucose molecule continues to gradually break down
into carbon dioxide following one of two paths:
aerobic or anaerobic. In human cells, glucose is
entirely broken down into carbon dioxide through
aerobic respiration. However, in the absence of
oxygen, the molecule will follow the anaerobic
process known as fermentation. Fermentation
produces alcohol and carbon dioxide, and although
fermentation can yield energy from glucose,
anaerobic respiration is much less efficient than
aerobic respiration (Lewis and others 2004).
Although it is scientifically proven that glucose is
the source of energy for all cellular respiration, how
does the substitution of sugar with artificial
sweeteners affect the metabolic process of cellular
respiration?
By means of fermentation, the aim of this
experiment was to determine the metabolic
difference, if any, between table sugar (sucrose) and
the artificial sweeteners Equal (aspartame) and
Splenda (sucralose). A study done by Keating and
White (1990), studied the effect of artificial
sweeteners in yogurts. In order to evaluate the
overall quality of artificially sweetened yogurt, plain
and fruit flavored yogurts were mixed with different
sweeteners and were incubated at 34ºC. Amongst
the sweeteners studied were sucrose, aspartame and
saccharin (Sweet N’Low). Results from their
investigation showed that sucrose developed a
slightly higher amount of lactobacillus, (the
bacterium that ferments lactic acid from sugars) than
most of the artificial sweeteners tested including
aspartame and saccharin (Keating and White 1990).
Because lactic acid fermentation is similar to the
anaerobic process of alcoholic fermentation, it is
expected that sucrose will metabolize a greater
amount of carbon dioxide than both Equal and
Splenda.
Materials and Methods
A yeast solution was prepared by activating 7g of
baker’s yeast (Saccharomyces cerevisiae) in 472.3ml
of heated (46.1ºC) deionized water. Separate 5%
solutions were prepared for C&H Pure Cane Sugar®
(sucrose), Equal® (aspartame) and Splenda®
(sucralose), by dissolving 10g of sugar in 200ml of
deionized water heated at 43ºC.
Fermentation tubes were filled with 8ml of yeast
solution and 8ml of sugar solution.This procedure was
repeated for each sugar group according to its
determined sample size. A sample of five tubes was
created for sucrose, ten tubes for Equal and ten tubes
for Splenda. An additional group of 5 tubes filled with
8ml of yeast and deionized water was added to serve
as a control group. A total of 30 fermentation tubes
were filled and sealed tightly with corks. All of the
tubes were then placed in an incubator at 37ºC for a
period of 24hrs. After the 24 hr. incubation period,
any carbon dioxide production in the tubes was
measured by using a millimeter ruler.
Results
Results showed a moderate difference in the means
of carbon dioxide production amongst the three sugar
groups. Splenda® produced the greatest amount of
carbon dioxide with an average of 2.4ml followed by a
mean of 1.075ml that was produced by Equal®, while
sucrose produced the lowest average amount of .64ml
(Figure 1).
ANOVA data analysis resulted in a P value of
0.232, which indicates no statistical difference
(p<0.050) between the three sugar groups.
3
2.4
2.5
CO2 produced (mL)
Introduction
2
1.5
1.075
1
0.64
0.5
0
Sucrose
Equal
Splenda
Sugar Category
Figure 1. Average amount of carbon dioxide
produced by each sugar category.
56
Saddleback Journal of Biology
Spring 2006
Discussion
Mean values for the amount of carbon dioxide
product collected from each sugar category revealed
that both Equal® and Splenda® produced a greater
amount than sucrose. Because the hypothesis
predicted that neither Equal® nor Splenda® would
produce a higher amount of carbon dioxide, the data
does not support the hypothesis. Although there is a
subtle difference in gas product amounts, data
analysis indicated that there is no considerable
variation in the metabolism of sucrose, Equal®, or
Splenda®.
There may be various reasons why there was no
significant difference in carbon dioxide product
between the sugar groups. One reason may be that
the sugar concentration of the solutions used in this
experiment may not have been high enough to yield
significant results.
Previous studies identified
measurable differences in the fermentation of
Saccharomyces cerevisiae in a high sugar
concentration medium versus lower sugar
concentrations (Meyers and Others 1996).
The next study will involve fermentation of
artificial sweeteners utilizing different levels of
sugar concentration. Furthermore, investigating the
stability of sugar and the sweeteners in various
temperatures might also be instrumental in
determining factors that differentiate the metabolizing
of sucrose, Aspartame and Sucralose.
Literature Cited
Keating K, White C. 1990. Effect of Alternative
Sweeteners in Plain Yogurt and Fruit-Flavored
Yogurt. Journal of Dairy Sci.73(1):54-62.
<http://jds.fass.org/cgi/reprint/73/1/54> 2006 March
17.
Lewis R, Gaffin D,Hoefnagels M, Parker B. 2004.
Saddleback College Introduction to Biology. New
York: McGraw-Hill. 981p.
Myers D, Lawlor D, Attfield P. 1996. Influence of
Invartase Activity and Glycerol Synthesis and
Retention on Fermentation of Media with a High
Sugar Concentration by Saccharomyces cerevisiae.
Appl. Envir. Microbiol. 63 (1): 145 – 150.
The Effect of Light Wavelength on the Growth of Onions, Allium cepa
Nastaran Aghazadeh and Brittney Moyers
Department of Biological Sciences
Saddleback College
Mission Viejo, California USA
Onions (Allium cepa) are a green plant with a long stem in which light and water play a
major role in its growth. Too much light may cause the plant to become dry and wilted. In
Palestinian Bronze Age settlements, traces of onion remains were found dating back to
5000 BC. The edible bulb is one major characteristic of the onion plant. The purpose of the
present experiment was to determine the effect of red, blue, and white light on onion
growth. In the experiment, three groups of onion sets were planted about two centimeters
below the surface of the soil. PVC structures were built around two groups of Allium cepa.
One group was covered in red cellophane and the other covered in blue. The third group
was placed under sunlight (white light). Data were collected every two weeks for one
month. The results revealed that the onions placed under blue light were significantly
taller than those placed under red light (ANOVA, p=0.001). One reason for these results
may be that there was more moisture inside the PVC structures than in the white light
group which was caused when it rained. Another reason could be that the intensity of the
blue light may have been greater due to the colored cellophane.
Introduction
Allium cepa is a plant that grows in soil from a
long stem in the beginning. It is a plant of the family
Liliaceae and it has the same genus (Allium) as the
chive (A. schoenoprasum), garlic (A. sativum), leek
(A. porrum), and shallot (A. ascalonium) (Winik,
2000). These plants are characterized by an edible
bulb composed of food-storage leaves that are rich in
57
Saddleback Journal of Biology
Spring 2006
40
35
30
25
Height (cm)
sugar and pungent oil, the source of its strong taste
(Anonymous 2006). The purpose of the present
experiment was to determine the effects that
different colored lights on Allium cepa. The
cellophane was transparent in order to allow the
light to pass through it. Transparent materials that
control the color of the light passing through them is
called filter (Wadsworth, 2001). The wavelength of
light differs from color to color. White light has a
wavelength of 390-790 ηm and the blue light wave
length is 455 – 495 ηm, and red light wave length is
625 – 780 ηm. It was assumed that plants exposed
to white light will grow taller than the plants
exposed to other colors. In order to find the result
variety of test needed to verify the hypothesis.
20
15
10
5
0
Blue
The mean initial height of the plants under white
light was 0.48 cm and its final mean height was
27.88 cm. Plants exposed to blue light had a mean
initial height of 0.11 cm and a mean final height of
33.29 cm. The plants under red light had a mean
initial height of 0.08 cm and mean final height of
19.66 cm. The data suggested that plants absorb the
blue light the most therefore can undergo
photosynthesis more efficiently than the plants under
red and white light. The plant under white light had
close results to the red light plant. And the blue light
plants were extremely taller than the other two
groups (Figure 1).
There was a statistical difference in the final mean
heights for the three color groups (ANOVA, p=0.001).
After the Bonferroni Correction, only plants under
blue light were statistically taller than plants under
white and red light. There was no difference between
the heights of the white and red plants.
Plants heights were measured two week intervals.
Plants under the white light grew at a more consistent
rate overall than blue and red light plants (Figure 2).
35
3
0
2
5
Average Height (cm)
Results
White
Figure 1.The mean final heights of onion plants exposed to blue
light, red light, and white light.
Material and Methods
Allium cepa were placed in soil under different
color light. The PVC was used for the support. The
blue cellophane and red cellophane were wrapped
around the PVC pipe to give it a color effect.
Twenty onions were planted under each light 2 cm
deep and 2.5 cm apart in potting soil under sunlight,
blue light, and red light. The onions were watered
twice a week using tap water. The height of this
plant was measured by using a meter stick in
centimeters. The meter stick was placed above the
soil to measure the tallest stem on each onion plant.
The data was collected in three groups of twenty
every two weeks for one month.
Red
Light Color
2
0
1
5
1
0
Blue
Red
5
White
0
28-Feb-06
14-Mar-
28-Mar-06
.
Dates Onions Were Measured
Figure 2. The average growth of onions exposed to
red, blue and white light measured every two weeks
for one month.
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Saddleback Journal of Biology
Spring 2006
Discussion
The measured heights along with the various
tests provided evidence that the onions under white
light were not significantly taller than those under
blue light and red light. Onion smut is a disease
common to temperate growing regions, especially
where onions are grown from seed. Lesions appear
as dark brown streaks running up and down the
leaves (H.A. Wadsworth, 2001). None of the
experimental groups exhibited any symptoms of
smut.
There may be several reasons why the white
light group did not grow as tall as the blue light.
Compared to the sunlight (white light group), the
blue cellophane may have intensified the light
directly hitting the onions. The use of minimally
opaque and optically accurate wavelength filters
rather than inexpensive cellophane would obviously
provide an exponential increase in accuracy (Winik,
2000).
In order to determine the problem each group
was compared. There may have been several reasons
why the white light plants did not grow taller. The
error might have been when recording the data or it
also may have been when the light got passed
through the cellophane.
Moisture may have been kept inside of the
structures covered with colored cellophane, however
the white light plants were placed directly under the
sun light and the moister may have been evaporated.
Therefore, the plants exposed to white light may have
been in a more arid setting than those exposed to
colored light.
Literature Cited
Anonymous. 2005. How light color influences plant
growth. Countryside and Small Stock journal 89 (4):
68.
Lee L. 2005. The versatile onions.
Activities 36 (2): 10.
Science
Russ K. 2002. Onion, Leek, Shallot and Garlic.
Home Vegetable Gardening 64 (5): 72.
Sell R. 1993. Onions. Alternative Agriculture Series
17(45): 22.
Wadsworth HA. 2001. Diagnosis and Control of
Onion Diseases. Plant Pathology 23
(3): 1.
Winik D. 2000. Impact of Light Wavelength on
Photosynthetic Rate in Arabidopsis thaliana. 3 (1):
27.
The Effect of Music on Heart Rate and Lap Time During Exercise in Humans
(Homo sapiens)
Naina Venkatesh and Arunkumar Sewchurn
Department of Biological Sciences
Saddleback College
Mission Viejo, CA 92692
In this study, the effect of music on heart rate performance (measured by lap time) was
examined using a heart rate monitor, and subsequently, lap pace/runtime and average
heart rate was determined. Music has become an integral part of fitness performance as it
provides motivation and distraction. The present study was designed to investigate whether
or not music or lack thereof, along with the type of music listened to during an 800m run
had any effects on heart rate and exercise performance levels. It was predicted that there
would be a significant difference in both heart rate and exercise performance with regards
to the type of music or lack thereof, administered to particular subjects (N=10). Individuals
who listened to pop music had higher heart rate levels than those of classical or no music
(Average heart rate of the pop music group, no music group, and classical music group
were 194.75beats/min, 168.31beats/min, and 156.85beats/min respectively). It was found
59
Saddleback Journal of Biology
Spring 2006
that there was no significant difference in heart rate between the no music and classical
music groups. However, there was a significant difference in heart rate between the no
music and pop music group (ANOVA test, p<0.0167). Similarly, there was a significant
difference in heart rate between the classical music and pop music groups (ANOVA test,
p<0.0167). The average lap time for the pop music group, classical music, and no music
group was 112sec/lap, 116.6sec/lap, and 122.4sec/lap respectively. According to ANOVA
test, there was a significant difference in lap time between the no music and the classical
music group (p<0.0167). Likewise, there was a significant difference in lap time between
the no music and pop music groups (ANOVA test, p<0.0167). There was a similar result
between the classical music and pop music group (ANOVA test, p<0.0167). These findings
demonstrated results that support the idea that music is a highly influential factor for heart
rate and exercise performance.
Introduction
Music has often been seen as a source of
motivation, inspiration, and distraction during
strenuous physical activity. Many leading
researchers in the field have demonstrated a strong
connection between music and performance. The
“right” music can have a very positive impact on
performance (Anshel and Marisi, 1978). The effect
of music on heart rate and overall performance has
been of particular interest to many because of the
benefits it presents in health and disease prevention.
Pujol and Langenfeld (1999), through their
“Wingate Anaerobic Test,” found that music has a
beneficial effect on sub-maximal physical
performance. Many do not realize that music has a
tremendous impact on a person’s ability to exercise
effectively. Kennedy and Newton (1997) found data
that supported the idea that music has the ability to
increase the amount of pleasure while training with
increased load/efficiency levels. Music has the
ability to create an arousal state in which individuals
may be able to distract themselves and focus on
other variables rather than the task at hand and thus
may block any negative distractions (Dorney et al.,
1992).
However, the appropriate selection of music can
induce various results. Many people feel it is easier
to exercise while listening to music. Beckett (1990)
found that while listening to music, people walked
farther and recovery of their normal heart rate (HR)
following exercise occurred more rapidly. People
say it excites them and helps them forget about the
pain and fatigue they are enduring.
Likewise, many people admit to adjusting their
intensity and vigor according to the type of music
(tempo) they are listening to and subsequently affect
their heart rate and performance ability (Dainow,
1977), suggesting that heart rate increased with pop
music and decreased with slow, perhaps classical
music. In another study, heart rate was found to
decrease after listening to classical music, but it did
not change after listening to popular music
(Mornhinweg 1992). Gardner et al., (1960) found that
slow-soft tempo music aided in relaxation.
Furthermore, Copeland and Franks (1991) found that
slow music led to a decrease in perceived exertion.
The heart is a vital organ in the human body.
Though its size is small, it pumps blood to the rest of
the body by expansion and contraction. This cycle is
called heart rate. It is the number of contractions
(beats) per minute. Heart rate tends to increase with
response to a wide variety of conditions, like physical
activity. Music therefore can have an effect.
Furthermore, scientists have demonstrated that
they can change heartbeat and other vital functions
through the direct use of music. It has been discovered
that music is an ergogenic aid. Likewise, in many
cases, the increased work output has directly
corresponded with an increase in final heart rate
readings, suggesting that subjects were more
motivated to push themselves harder while listening to
music (Crust: accessed 2006). Karageorghis, (1999)
also found that performance improved by 5-7% when
exercisers or participants subjected themselves to
music while exercising.
In the current study, Venkatesh and Sewchurn
monitored heart rate in ten healthy men and women
ranging in ages from 18-25. The study addresses the
effects of music with respect to heart rate levels and
runtime exercise performance. Pop music is defined as
being upbeat, vigorous, energetic and stimulating.
Britney Spears’ song “Do Something” was used as the
pop music selection. For classical music, Chopin’s
“Fantasie Impromptu” was used. Classical music is
defined as being sweet, melodious, soothing in tone
and relaxing in rhythm. The nature of music is known
to have a profound effect on these two variables. In
general, the more upbeat and stimulating a piece of
music is, the more the body’s natural response is to
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Spring 2006
increase heart rate and exercise performance levels
and vice versa.
It was hypothesized that the administration of
pop music would have the most increased effect on
overall heart rate and exercise performance.
Subsequently, it was believed that there would be a
significant difference in the three categories (pop
music, classical music, and no music) with respect to
heart rate and exercise performance.
Materials and Methods
The general aim of this study was to determine
the effect, if any, music has on overall heart rate and
exercise performance. Ten subjects (five males and
five females) ranging in ages from 18-25 of similar
health and activity levels were selected for this
study. Two pieces of music, one from Britney
Spears and the other by Chopin were chosen as
selections for this experiment. This study required
the individuals to perform a two lap run (800m)
around a standard outdoor track at Aliso Niguel
High School. The subjects were informed of the
experiment, what is entailed, and what it was being
done for. There were no pre or post-tests performed
that would affect any part of the outcome of the
entire experiment.
The exercises were performed during the
course of three days, that is, during the first day, the
subjects ran with pop music, the second day with
classical music and the third day they ran without
music. This was done in order to give enough
recuperation time to the subjects and eliminating the
variable of fatigue. Each day had similar weather
conditions, and therefore temperature that was
approximately 280C for all three days, wasn’t an
issue. Moreover, each subject was provided with an
iPod and a pair of headphones (1GB ipod nano,
model number A1137; purchased at Best Buy in
Mission Viejo, CA). The controlled group was
simply asked to run without music.
Furthermore, the volume of music supplied to
each subject was equalized and controlled at a
constant level. Each subject had his/her resting heart
rate measured before the exercise using a polar hear
rate monitor (Model # E600, Polar Electro Inc, 370
Crossways Park Drive, Woodbury, NY 11797)along
with their average heart rate and lap time during the
exercise. The polar heart rate monitor was provided
by Saddleback College Department of Biology.
Observations with regards to perceived exertion
were also noted. Observations were based on
breathing
intensity,
fatigue,
and
verbal
communication. Likewise, each day, ample water
was provided.
Subsequently, special care was taken to ensure
and control all variables and problems that might have
been incurred during this study. All subjects were
asked to consume consumed little food and drink
before experimentation (that might affect the outcome
of their specific trial). Once the average heart rate and
lap time for every individual were obtained after the
running exercise, computation of the data was done
with Microsoft Excel (Microsoft Corporation). This
enabled the researchers to generate a graph based on
the effect of music on the average heart rate of the ten
subjects against music genre, and another graph based
on average runtime per lap versus the three music
genres of the ten subjects. The results of the average
heart rate and lap time obtained among the three
groups were compared by one-way analysis of
variance (ANOVA) followed by a paired post-hoc test
in order to test for the significance of the data.
Significance was set for all tests at p<0.05 and then
divided by 3 for the three compared groups that
resulted in p being less than 0.0167 if the test was
significantly different.
Results
Firstly, it was found that the average resting
heart rate of the ten subjects was 79.4 beats/min. The
group that was subjected to pop music had the highest
average heart rate (Figure 1). There was no significant
difference in heart rate between the group that was
subjected to no music and the group that was
subjected to classical music (ANOVA test, p>0.0167).
However, there was a significant difference in average
heart rate between the group that was not subjected to
music at all and the group that was subjected to pop
music (ANOVA test, p<0.0167).Furthermore, there
was a similar result for the groups that was subjected
to classical music and the group that was subjected to
pop music (ANOVA test, p<0.0167). It was also
found that the group that was subjected to pop music
had the best performance with an average lap
time/runtime of 112sec/lap as compared to classical
and no music which had an average lap time/runtime
of 116.6sec/lap and 122.4sec/lap respectively (Figure
2). According to the ANOVA test, there was a
significant difference in performance between each
group (ANOVA test, p<0.0167).
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Saddleback Journal of Biology
Spring 2006
Average Heart Beats Per Min
(Beats/Min)
Discussion
250
194.75
200
168.313
156.85
150
100
79.4
50
0
Resting Heart
Rate
No music
Classical music
Pop music
Music Genre
Figure 1. Effect of music genre on the average
heart rate of ten subjects that were subjected to
running two laps (800m). There was no significant
difference in heart rate between the group that was
subjected to no music and the group that was
subjected to classical music
(ANOVA test,
p>0.0167). There was a significant difference in
heart rate between the group that was subjected to
no music and pop music; and similarly, there was a
significant difference in heart rate between the
subjects that were subjected to classical music and
pop music (ANOVA test, p<0.0167).
124
122.4
Runtime (Sec/Lap)
122
120
118
116.6
116
114
112
112
110
108
106
No music
Classical music
Pop music
Music Genre
Figure 2. Average runtime/lap time on three music
genre of ten individuals (five males and five females)
subjected to running 800m.There was a significant
difference in performance between the groups that
was subjected to no music and the group that was
subjected to classical music (ANOVA test,
p<0.0167). In the same way, there was a significant
difference in performance between the groups that
was subjected to no music and the group that was
subjected to pop music (ANOVA test, p<0.0167).
Similarly, there was a significant difference in
performance between the groups that was subjected
to classical music and the group that was subjected
to pop music (ANOVA
test, p<0.0167).
The purpose of this experiment was to discover
whether or not music and music type had any
significant influence on heart rate and exercise
performance. The results of this investigation
supported the initial hypothesis partially in that heart
rate would increase with pop music; however there
was no significant difference in heart rate between the
no music group and classical music group. Moreover,
the outcome of exercise performance was also
significantly based on type of music, where people
who listened to pop music ultimately exercised more
efficiently (they had a higher heart rate and best
runtime/lap time) than those who were subjected to
the other two variables (classical music and no music).
Classical music was second and no music was third in
exercise performance level that was primarily based
upon runtime/lap time during experimentation.
Furthermore, the researchers discovered by
observation that the perceived rate of exertion was
more evident in those who didn’t listen to music at all,
than those who listened to either pop or classical
music. The results of this experiment support past
research evidence which suggests that heart rate and
performance tends to increase with response to a wide
range of external conditions like vigorous activity and
music.
The researchers speculate that music may
provide many types of benefits during vigorous
exercise. Firstly, the researchers believe that music
provides a sense of excitement, which in turn
increases blood pressure, which in turn increases heart
rate to the optimal target heart rate quicker than if
there was no music. Listening to music also provides a
form of distraction, and it helps the exerciser forget
about feelings of pain and fatigue they are feeling
during physical activity. Ellis and Brighouse (1952)
observed that respiration rate increased significantly
with the onset of jazz music (which is comparable to
pop music due to its upbeat and fast stimulating tone)
suggesting that heart rate also increased.
Dainow (1977) also noted similar results that
showed that heart rate tended to follow music tempo,
increasing in response to fast music and decreasing in
response to slow music. He furthermore concluded
that music produced some kind of emotional effect on
the individual, suggesting that heart rate responds to
such action. Karageorghis (1997) also provided an
understanding as to how music benefits people. He
found that music is an appropriate tool for focus
because it helps relieve boredom and decreases a
sense of effort; therefore distracting the individual
from the task at hand. He further determined this
effective disassociation tends to activate a positive
mood state through avoidance of negative thoughts of
tiredness and pain. And most importantly, it helps
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Saddleback Journal of Biology
Spring 2006
maintain interest in the activity (Karageorghis, et al.
1996). Likewise, current research has indicated that
a relaxed and calm state of mind has a beneficial
effect on exercise efficiency (Copeland and Franks,
1991). It helps raise confidence and self-esteem
along boosting an individual’s interest in working
out (in this study, running).
Cromartie and Matesic (2002) further found
the positive effects of music engagement. They
realized that music enhances efficiency by
synchronizing movement with the beat of the music,
thus preventing any unnecessary and wasted motion.
It also provides an effective training pace. Human
rhythmic impulses tend to react to such external
stimuli, and such a reaction instigates a preferred
“work out rate.” Similarly, they discovered that no
matter the mode of exercise (treadmill, rowing,
isomeric strength training, etc), performance with
music appeared to improve. Moreover, previous
studies show that music helps relieve repetitive
training sessions, and enables an individual to
engage in maximum cardiac output and strength
training.
Literature Cited
Anshel, M.H. and Marisi, D.Q. 1978. Effect of
music and rhythm on physical performance.
Research Quarterly, 49, 109-113.
Beckett, A. 1990. The effects of music on exercise
as determined by physiological recovery heart rates
and distance. Journal of Music Therapy, 27: 126127.
Boutcher, S.H. and Trenske, M. 1990. The effects of
sensory deprivation and music on perceived exertion
and affect during exercise. Journal of Sport and
Exercise Psychology, 12, 167-176.
treadmill endurance. The Journal of Sports Medicine
and Physical Fitness, 31: 100-103
Crust, L. Ergogenic Aids: How turning on and tuning
in can boost your motivation and aid your workout.
Peak
Performance.
Available
at:
www.pponline.co.uk/encyc/0951.htm. Accessed April
2006.
Dainow, E. 1977. Physical Effects and Motor
Response to Music. Journal of Research in Music
Education, 25: 211- 221.
Dorney, L., Goh, E., and Lee, C. 1992. The impact of
music and imagery on physical performance and
arousal: studies of coordination and endurance.
Journal of Sports Behavior, 15: 21-33.
Elllis, D.S. and Brighouse, G. 1952. Effects of Music
on respiration and heart rate. The American Journal of
Psychology, 65: 39-47
Gardner, W.J., Licklider, J.C.R., and Weisz, A. 1960.
Suppression of pain by sound. Science, 132: 32-33.
Karageorghis, C. Music in Sport and Exercise: Theory
and practice. The Sport Journal 2 (2), Spring 1999.
Available at: http://www.thesportjournal.org/1999Journal/vol2-No2/Music.asp. Accessed: April 2006.
Koschak, E. 1975. The influence of music on physical
performance of women. Master’s Thesis. Central
Michigan University.
Mornhinweg, G. 1992. Effects of music preference
and selection on stress reduction. Journal of Holistic
Nursing, 10: 101-109.
Pujol, T. and Langenfeld, M. 1999. Influence of music
on Wingate Anaerobic Test performance. Perceptual
and
Motor
Skills,
88:
292-296.
Copeland, B.L. and Franks, B.D. 1991. Effects of
types and intensities of background music on
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Saddleback Journal of Biology
Spring 2006
THE EFFECT OF ALCOHOL-BASED AND
NON-ALCOHOL-BASED MOUTHWASH ON
GROWTH
OF
POTENTIAL
PLAQUE
PRODUCING BACTERIA IN THE GUMLINE.
Kari A. Prettyman. Department of Biological
Sciences, Saddleback College, Mission Viejo, CA,
92692
The use of mouthwash in preventing growth of
plaque-producing bacteria is a widespread practice
in oral health care today. In this experiment, the
effects of alcohol-based and non-alcohol-based
mouthwash on the inhibition of normal gumline
bacteria were studied. The Kirby-Bauer in vitro
disk-susceptibility testing technique was applied. On
inoculated nutrient agar plates, the zone of bacterial
inhibition, which surrounds a sterile disk saturated
with mouthwash, was measured in centimeters. The
average inhibition diameter around the alcoholbased mouthwash (Scope) was 1.22cm (N=12), and
around the non-alcohol-based mouthwash (Crest)
was 1.31cm (N=12). T-test analysis revealed no
significant difference in the efficacy of preventing
bacterial growth between alcohol-based and nonalcohol-based mouthwashes (p=0.3840). However,
there was an obvious and apparent difference
between using water (control zone of inhibition
0.0cm) and either of the mouthwashes, using a
combined average of 1.26 cm (p=0.022).
CONCURRENT AND DELAYED EFFECTS OF
UV RADIATION ON PHOTOSYNTHESIS IN
SPINACH
LEAVES.
Michael
Gordon.
Department of Biological Sciences, Saddleback
College, Mission Viejo, CA, 92692.
The effect of heightened levels of UV radiation on
photosynthesis is of considerable interest in order to
understand the potential consequences of future ozone
layer depletion. This study set out both to determine
the significance of short-term exposure to heightened
levels UV radiation, and to suggest whether UV
inhibits photosynthesis by immediate interference, or
by accumulated damage to plant cells. Spinach leaves
were cut into discs then sunk by replacing the air with
2% bicarbonate solution. Consequent leaf floating
indicates photosynthetic activity. In the first
experiment, leaf discs were exposed to ultraviolet light
and visible light at the same time for 20 minutes.
Results were tallied for Control, (+)UV-A, and
(+)UV-B groups. No significant difference was found
in the concurrent test. In a second experiment, discs
were kept in the dark and exposed to the same levels
of UV-B for 20 minutes. Afterward, control and
(+)UV-B samples were exposed to visible light and
timed until all leaf discs floated. Prior UV-B exposure
significantly inhibited photosynthesis as determined
by a paired t-test (p <0.05). As the concurrent test by
contrast yielded no significant difference, the results
THE EFFECT OF PH ON THE SURFACE
BREATHING OF GOLDFISH (Carassius
auratus). Mark Reyes and Cody Pai. Department
of Biological Sciences, Saddleback College, Mission
Viejo, CA 92692, USA.
Surface breathing in fish usually occurs when the
oxygen levels of the water are low, or when the fish
are hungry. The fish need to replenish their oxygen
supply to maintain an acceptable metabolic rate.
One way of fish to compensate for the lack of
oxygen is to increase opercular pumping, surface
breathing, on the other hand, can help with the fish’s
oxygen intake. In this study, eight goldfish were
used to determine the time it takes for the initial
surface breath, as well as the number of surface
breaths taken in a controlled solution (pH 5.5, 20°C)
versus an acidic solution (pH 4.0, 20°C). The results
show that there is not a significant difference (p =
0.218, two-tailed t-test) in the mean time it takes for
these fish to take the initial surface breath in the
controlled environment (379.1±49.8s) versus the
acidic environment (273.1±64.9s); however, the
mean number of breaths taken under the controlled
environment (40±11 breaths) showed a significant
difference (p = 0.046, two-tailed t-test) from the
acidic environment (65±12 breaths).
THE EFFECT OF PH ON SEED GERMINATION
OF RADISH (Raphanus sativa). Marla M. Fortner
and Elham Zarnegar. Department of Biological
Sciences, Saddleback College, Mission Viejo, CA,
92692.
The onset of industrial growth has had a profound
impact on the environment. As a result, pollutants are
expelled into the air causing much concern for those
in the agricultural field. Previous experimentation on
cabbage has provided evidence suggesting that acid
rain has an effect on growth when damage on the
leaves is present. Because plants in the early stages of
growth are more susceptible to damage than their
older counterparts, radish seeds were chosen to test for
potential effects on germination. An experimental
group of seeds were germinated in a nitric acid
solution pH 4.5, while deionized water pH 7.0 was
used for the control group. Seeds germinated in the
nitric acid solution yielded a result of 100 percent
germination as opposed to seeds germinated in
deionized water which yielded a result of 94 percent
(p< 0.05). These findings contradict the results of
previous experiments conducted on plants in early
stages of growth, for radish in the germination stage
was not adversely affected by the simulated acid rain,
thus there is no significant difference on seed
germination associated with acid rain.
64
Saddleback Journal of Biology
Spring 2006
OVERFEEDING
GOLDFISH
(Carassius
auratus)
LEADS
TO
AMMONIA
PRODUCTION
AND
BEHAVIORAL
CHANGES. Lizbeth M. Barrera and Felicia Dang.
Department of Biological Sciences, Saddleback
College, Mission Viejo, CA, 92692.
Goldfish, Carassius auratus, overfeeding increased
ammonia excretion, enabling their regular functions.
Goldfish are very good at regulating their own tanks/
environment.
They are known in certain
circumstances, acidic water, to increase renal
ammonia to change the pH. The experiment
provided evidence by starting with water that was
slightly acidic then going to a more basic
environment within a week’s time. As the goldfish
pH level increased from a 6 to 8( ± .01)on the pH
meter, it affected their daily activity. In their daily
activity they swam around frequently and had
overall greater activity than when the pH level
started to rise – overfeeding. When they were
overfed, creating more ammonia, they became more
docile and sunk to the bottom of the bowl. So overfeeding a goldfish affects environmental pH levels.
THE EFFECT OF WAVELENGTH ON
CRASSULACEAN ACID METABOLISM IN
JADE PLANTS. Brian C. Oliver. Department of
Biological Sciences, Saddleback College, Mission
Viejo, CA, 92692.
Crassulacean Acid Metabolism (CAM) is common in
desert-dwelling plants and has been proposed as an
evolutionary mechanism to prevent water loss through
stomata. More recent studies have found CAM to be
present in ferns in a moist habitats. This would
suggest that CAM may be an evolutionary response to
natural selection for increased carbon fixation. It was
hypothesized that the light reactions of CAM
photosynthesis would progress more rapidly under
varying wavelengths in Jade plants (Crassula
argentea). Jade plants had ending pH values of 4.28
when held under blue light (476nm peak), 4.26 when
held under green light (534nm peak), and 4.16 when
held under bred light (700 nm peak). There was a
significant decrease in pH level of the plant tissue
(p<.05, one-tailed test of t) in blue and green
conditions versus red conditions.
EFFECT OF COPPER SULFATE ON
GROWTH OF AN AQUATIC MACROPHYTE,
ELODEA (Elodea canadensis). Neima Ghassemian
and Amin Salek. Department of Biological Sciences,
Saddleback College, Mission Viejo, CA, 92692.
Elodea canadensis has been proposed as a potential
biomonitor due to its wide distribution and apparent
ability to delete pollutants in aquatic ecosystems.
We investigated the effects of copper sulfate on
growth in E. canadensis to determine its
effectiveness as a biomonitor of copper pollution in
aquatic systems and whether growth is a suitable
index of sub-lethal stress. Copper sulfate
significantly slowed or stopped growth at 7ppm.
Final plants were significantly lower in height in
copper sulfate treatments compared with controls.
The one tailed t-test generated a P value of .0412
that explains the significant difference between the
experimental and control data. Elodea canadensis
appears to be very sensitive to copper levels, and
may be useful as a biomonitor of copper levels in
aquatic systems.
However, it's utility as a
bioaccumulator may be limited, because we
observed senescence of most leaves in all coppertreated plants following 3 weeks of treatment.
THE EFFECT OF LIGHT ON OXYGEN
PRODUCTION IN AN AQUATIC PLANT
(Elodea canadensis).
Yelena I. Martinez.
Department of Biological Sciences, Saddleback
College, Mission Viejo, California USA.
Studies show that the rate of oxygen consumption
with marine organisms is greater with the presence of
light compared to when dark reaction occurs. To test
this hypothesis the concentration of dissolved oxygen
(DO) was determined by the Winkler titration method
for Elodea canadensis plants in the light and dark.
The average dissolved oxygen (DO) concentration for
plants kept in the light was 18.47 ppm ± 0.23 (±se,
N=3).
The average Dissolved Oxygen (DO)
concentration for plants held in the dark was 9.23 ppm
± 0.73 (±se, N=3). A two-tailed t-test revealed that
the average dissolved oxygen concentration of the
light set-up was significantly higher than that seen in
the dark (p=0.01). The results therefore support the
hypothesis that light affects the rate of oxygen
production in aquatic plants.
65
Saddleback Journal of Biology
Spring 2006
VARIATION IN THE RATE OF POLLEN
GERMINATION IN THE ASIATIC LILY
(Lilium
sp.)
AT
DIFFERENT
TEMPERATURES. Nicolas Cruz, Callan Taylor,
and Sadaf Bahadoran. Department of Biological
Sciences, Saddleback College, Mission Viejo, CA,
92692.
Pollination, the transfer of pollen grains to the plant
carpel containing the ovule, is an important step in
the reproduction of seed plants (Swanson et. Al.
2004). External signals like temperature can actually
affect how much pollen is actually is being
pollinated at any given time. To test this theory a
study was done on the pollination of a type of lily
called Lilium sp. In the study recorded the length of
pollen tube that extended from each flower at two
different temperatures. The results indicated that
there was a twenty-eight percent more pollen had
pollinated at 37° C then those placed at room
temperature. The results illustrate that there was a
significant difference between the lengths of pollen
tubes at two different temperatures. It was concluded
that temperature did indeed affect the rate of
pollination in plants, in particular these lilies.
THE EFFECT OF POLARIZED LIGHT ON
THE RATE OF PHOTOSYNTHESIS IN
SPINACH PLANTS (Spinacia oleracea). Victor
Eleazar and Jennifer Ferrara.
Department of
Biological Sciences, Saddleback College, Mission
Viejo, CA, 92692.
Polarized light is the light used for photosynthesis in
forests where a canopy filters much of the sunlight.
This study is based on the rate of oxygen production
in spinach leaves which is proportional to its
photosynthetic rate. Ten spinach leaf discs were
removed of their oxygen with a vacuum flask,
placed in a Petri dish containing 0.2% sodium
bicarbonate solution, placed under an incandescent
lamp, and were observed under a measured light
intensity, both with and without a polarized light
filter until 100% of the discs produced enough
oxygen to float.
Polarized light significantly
increases the rate of photosynthetic rate (p=.04).
THE EFFECT OF RED-COLORED PLUMAGE
ON FEEDING DOMINANCE IN THE MALE
HOUSE FINCH (Carpodacus mexicanus). Lauretta
M. Rustad, Abdullah Ibish, and Erik Bosshart.
Department of Biological Sciences, Saddleback
College, Mission Viejo, CA, 92692.
In many species, the brightness of carotenoid-based
plumage reflects the health and condition of the
individuals and is used in mate selection. In this
study, our objective was to examine phenotypic
correlates of dominance among male house finches
and since there is evidence of higher dominance levels
being associated with brightly ornamented males, it
was our hypothesis that male finches displaying
brightly carotenoid-based plumage would be more
dominant in feeding situations than drab males. Ad
libitum supplies of seeds, grains, fruits, vegetables,
fatty acids, vitamins and minerals, protein, and
carbohydrates were given through a modified the bird
feeder so that only one finch could feed at a time.
Dominance was measured by tracking wins and losses
during aggressive interactions for food between male
finches. Interestingly, based on our definitions of
bright and drab, in direct opposition to our hypothesis,
drab males won significantly more than brightly
colored males (p=0.03, chi-squared “goodness of fit”
test, assumed test against a null hypothesis of 50/50).
LEARNING CAPABILITY IN GOLDFISH
(Carassius auratus auratus). Sandra Farmand, Heba
Elsherif, and Azadeh Salek. Department of Biological
Sciences, Saddleback College, Mission Viejo, Ca,
92692.
The capacity of spatial learning in goldfish is said to
be comparable to that of rodents. The present study
examined spatial learning in goldfish using a tank that
contained two glass plates. Each plate consisted of one
hole, which measured to be one inch in diameter. The
subjects were motivated to reach the baited hole. As
the task of reaching the end of the maze was
accomplished, the fish would then be rewarded with
bloodworms. We hypothesized that their performance
in completing the task would decrease in time by the
fifth trial. There were seven subjects being studied and
they averaged to be 3.5 cm ± 0.5 in size. The
procedure was to place each goldfish separately inside
the tank for an unlimited amount of time. The time
that it took for the goldfish to reach the end of the
maze was recorded. The average time it took the
goldfish for the first day was 38 minutes (± 8.89
S.E.N=7) and the average time for the fifth day came
to be 52 minutes (± 9.36 S.E.N=7). In the unpaired ttests the p-value was 0.012. These results
demonstrated that there was a significant difference
66
Saddleback Journal of Biology
Spring 2006
THE
EFFECT
OF
LOW
PARTIAL
PRESSURES ON THE PH OF CAM PLANT
LEAVES. Eugene Kang and Marcus A. Donovan.
Department of Biology, Saddleback College,
Mission Viejo, CA, 92692
Crassulacean acid metabolism (CAM) plants uptake
CO2 at night through there leaves and store it as
malic acid that can be broken down during the day
for sugars. This uptake of CO2 at night causes CAM
plants to become more acidic resulting in a lower
pH. Our experiment involved three groups of leaves
from a jade plant (Crassula ovata). Each group
consisted of 30 leaves all picked from the same jade
plant. One group was a start group which we
determined the pH of right after picking them from
the plant. The second group was stored in the dark
for 48 hours. The third group was stored in the dark
and placed in a vacuum at half pressure for 48 hours.
The pH levels of both the control group (48 hours of
in darkness at regular pressure) and the experimental
group (48 hours of darkness at half pressure) both
decreased significantly from the starting pH which
had a mean pH of 5.31 (±SE, 0.01, p=8.25x10-17 and
p=8.36x10-19 respectively). The leaves held at the
lower pressure (pH of 4.74 ±SE, .01) had a
significantly higher pH than the control (pH of 4.43
±SE, 0.01) group (p=1.88x10-07).
EFFECT OF TEMPERATURE ON GARDEN
BEAN GERMINATION.
Kelly Murphy.
Department of Biological Sciences, Saddleback
College, Mission Viejo, CA, 92692
The temperature of the surrounding environment
effects the growth of plants. Since most plants grow
best in warm temperatures, it was predicted that
garden bean seeds would germinate quicker at higher
temperatures than in a cooler environment. The bean
seeds were placed at different temperatures (T= 21°C
and T= 6°C) and the number of seeds germinated were
counted each day for a week. A correlation between
the temperature increase and the increase in number of
germinated seeds was observed.
The difference
between the rate of time it took the bean seeds to
germinate was measured by the percentage of the
seeds germinated overall. The seeds kept in the higher
temperature experienced a ninety percent increase
over the refrigerated seeds.
THE EFFECT OF TEMPERATURE ON
CARBON
DIOXIDE
PRODUCTION
IN
GOLDFISH (Carassius auratus). Julia Mann.
In Vitro ANALYSIS OF POTATO (Solanum
tuberosum)
TYROSINASE
ENZYME
KINEMATICS. Thien H. Huynh and Philip J. Orwig.
Department of Biological Sciences, Saddleback College,
Mission Viejo, California 92692.
Changes in temperature have been shown to decrease the
availability of oxygen in the ambient environment of
goldfish (Carassius auratus). The present study was
developed to examine the amount of carbon dioxide
excreted by goldfish at varying ambient temperatures. It
was predicted that the goldfish exposed to a decreased
water temperature, and therefore a hypoxic environment,
would expel a significantly smaller amount of carbon
dioxide compared to those goldfish respiring under normal
ambient conditions. The amount of carbon dioxide
excreted during respiration is equivalent to the amount of
carbonic acid released into the water. Therefore, the
amount of carbonic acid produced was measured by
allowing the goldfish to respire in a closed system for 20
minutes, at varying ambient temperatures. Upon removal
of the goldfish, the water was titrated with a standardized
sodium hydroxide solution until the acid in the water was
neutralized and the endpoint met. The initial and final
volumes of sodium hydroxide were noted for calculating
the number of moles of acid. At a decreased temperature,
the average amount of carbonic acid in the water
(0.00038+0.00007 mol, ±s.e., N=6) was much less
compared to the amount excreted at a normal temperature
(0.00025+0.00005 mol, ±s.e., N=6) . However, there was.
Department of Biological Sciences, Saddleback College,
Mission Viejo, CA, 92692.
When functionally identical enzymes are extracted from
separate species, their catalytic rates may vary significantly.
This experiment examines two characteristics that can aid in
distinguishing isoenzymes by their associated reaction rates:
the Michelis-Menten constant (Km), and the maximum
reaction velocity (Vmax). Tyrosinase was first extracted from
Russet potato (Solanum tuberosum) and red yam (Diascorea
sp.) by a process of homogenization, protein precipitation,
centrifugation and filtering. The rate of catalytic conversion
of 3,4-dihydroxyphenylalanine (DOPA) to dopachrome was
then measured for each extract by determining the change
over time of light absorbance at λ = 475nm in a
spectrophotometer. Further work followed on a 10% dilution
of the tuberosum extract, which measured reaction velocities
of the enzyme over series dilutions of the substrate ranging
from 8 mM to 0.5 mM. Data from the change in reaction
velocities over varying substrate concentrations were then
used to create Michelis-Menten and Lineweaver-Burke
plots. From the Lineweaver-Burke plot, Vmax of the
tuberosum extract was determined to be 0.0108
μmoles/minute, while Km was 26.32 mM (linear regression,
R2=0.9993). Finally, PAGE protein profiles were run for
each extract to contrast the differing protein content between
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Saddleback Journal of Biology
Spring 2006
EFFECTS OF REGULAR EXERCISING ON
METABOLIC RATE AS MEASURED BY THE
RATE OF CARBON DIOXIDE PRODUCTION
IN
ACTIVE
AND
SEDENTARY
INDIVIDUALS. Shannel Busuioc and Sherry
Torng. Department of Biological Sciences,
Saddleback College, Mission Viejo, CA, 92692
Exercising in individuals is believed to increase
metabolic rate between resting and active levels.
Regularly exercising individuals are believed to
have a lower percentage change in metabolic rate
than sedentary individuals. Ten individuals were
chosen from a classroom to exhale air (blow
bubbles) into a solution with a phenolphthalein
indicator.
Two trials were taken from each
individual, one prior to exercise in a relaxed state
and another after riding an exercise bike for one
minute. Time to turn solution the clear was recorded
for each trial and percent increase in regular
exercisers was compared with non-regular
exercisers. Regular exercisers (mean 34.57 ± 10.89
se) had no significant percent increase in metabolic
rate from resting and active levels in comparison
with individuals who are sedentary (mean 34.29 ±
10.69 se). However, evidence was found that
regular exercising can heighten overall metabolic
rate in both resting and active levels.
THE PH EFFECT OF ASCORBIC ACID ON
HUMAN URINE. Yen Tran. Department of
Biological Sciences, Saddleback College, Mission
Viejo, CA, 92692.
The objective of this study was to see whether or not
that taking in a daily dose of Vitamin C would affect
the urine pH of a human being. Ten people were
observed during this study, their diets consisted of the
normal food intake but without any kind of substances
that contained Vitamin C. Subjects were prepared 2
days ahead of time to have no diets containing
Vitamin C so that results were more accurate. During
the study there was an initial reading of urine pH and
then after the initial reading the ten specimens orally
digested a Vitamin C tablet. The final reading of the
urine was taken immediately at the one hour mark
after the tablet was orally digested. Results were
recorded at a max pH of 7.5 and a low of 5.5.
P=0.24417 of the initial pH reading versus the final
pH reading. At this time there seemed to be little to no
significant difference whether if the Vitamin C tablet
even had an effect upon urine pH of the ten test
subjects tested.
OPERCULAR
PUMPING
RATES
IN
SMALLER AND LARGER GOLDFISH,
(Carassius auratus). Kareem D. Sharaf. Department
of Biological Sciences, Saddleback College, Mission
Viejo, CA 92692.
In order to investigate the opercular pumping rates
in goldfish due to size, 15 goldfish of one to three
centimeters, as well as 15 goldfish of three to five
centimeters were measured and their respirations
were counted. 15 Goldfish of each size were placed
into a 10 gallon tank equipped with filter and
oxygen pumps, each goldfish was then measured for
length and observed for opercular pumping for 2
minutes in room temperature. The smaller goldfish
had an opercular pumping rate mean of
178(SD=45.74) pumps, and the larger goldfish
showed a mean of 250(SD=23.48). Statistical
analysis done with a 95% confidence interval
showed the two-tailed p-value is less than 0.0001.
This difference is considered to be extremely
statistically significant. Goldfish of bigger size tend
to have greater opercular pumping rate then those of
smaller size.
PH LEVEL OF CAM PLANTS (Aloe Vera) LEFT
IN
THE
DARK
AT
DIFFERENT
TEMPERATURES FOR 72 HOURS. Zil Patel and
Summer Ford. Department of Biological Sciences,
Saddleback College, Mission Viejo, CA, 92692
CAM plants have a succulent property which enables
the plant to adapt to many different climate changes.
CAM plants photosynthesize during the day as well as
during the night. For plants sunlight is critical to
maintain a source of energy. Two Aloe Vera plants
were placed in two different environments. One was
placed in a room temperature dark environment and
the other was placed in an incubator of 37 °C in a dark
environment. Both of the plants were kept in their
environment for 72 hours. If a CAM plant is left in
the dark it will contain more malic acid therefore
being more acidic and a lower pH level. The result
indicated that the plant left in the room temperature
dark room had a lower level of pH (average 4.88) and
the plant left in the incubator had a high pH level of
(average 5.24). There was a significant difference in
the pH level between the plants since p= 3.22x10-04.
This indicates that an increase in the temperate of the
environment and a elimination of sunlight energy the
amount of malic acid produced decreases.
68
Saddleback Journal of Biology
Spring 2006
THE EFFECT OF INCREASED SUGAR
INTAKE ON THE ACTIVITY OF MICE. James
D. McMillian, Department of Biological Sciences,
Saddleback College, Mission Viejo, CA 92692,
USA
Human sugar intake has increased steadily over the
last few decades. It is generally believed that sugar
provides energy, and that an increase in sugar
provides an increase in energy.
This study
investigated the effect of an increase in sugar intake
on overall activity in mice. Fourteen mice were
separated into two groups of seven, labeled control
and experimental.
Both environments were
maintained in identical conditions with the singular
exception that the experimental group was provided
a 15% sugar and tap water solution while the control
group was given only tap water to drink.
Measurements of energy expenditure were
determined by calculating the distance traveled on a
six inch exercise wheel, which was monitored for 14
days while readings were recorded every 12 hours.
Final results indicated that the experimental group’s
total distance traveled decreased by 55.8% of that of
the control group.
Sugar intake did not correlate
with an increase in overall activity as measured in
this experiment.
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Saddleback Journal of Biology
Spring 2006