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GREEK AND LATIN FOR BIOLOGISTS
Many technical terms used in biology are derived from Greek or Latin. To help you in decoding
and remembering some of these terms, we have compiled the following list of Greek and Latin root-words
and their meanings.
a-, not, no
meta-, after, beyond
ab-, away from
mito-, thread
ad-, toward, to
morph-, form
ana-, up, constructive
myco-, fungus
auto-, self
myo-, muscle
bio-, life
blast-, bud
cardi(o)-, heart
cata-, down, destructive
cephalo-, head
chloro-, grass-green
chrom(a)-, coloured
cyt(o)-, cell
derm-, skin
ecto-, outside, upon
endo-, inside
epi-, outside, upon
eu-, good, true
gamete-, spouse
gastr(o)-, stomach-like
gen(o)-, descent
haemo-, blood
hetero-, unlike
histo-, tissue
hom(e)o-, alike, same
hypo-, less, lower
hyper-, more, higher
inter-, among, between
intra-, within
iso-, equal, same
karyo-, kernel, nucleus
kinesis-, movement
lysis-, break-up, losing
meio-, less, fewer
melan(o)-, dark, black
mer(e)-, part, segment
nephr(o)-, kidney
oo, ovo-, egg
ora-, mouth
peri-, around
phag(o)-, to eat
phase-, appearance
phase-, appearance
phor(e)-, bearer
phyco-, seaweed
phyco-, seaweed
phyll-, leaf
phyll-, leaf
phyto-, plant
plasm-, 'stuff'
plast-, moulded, shaped
pod(a)-, foot
pro-, before, previous
ren(a)-, kidney
rhizo-, root
sarc(o)-, flesh
sapro-, decayed
som(a)-, body
stoma-, mouth, opening
sym-, syn-, together
sub-, under, below
super, supra-, above
tax(o)-, arrangement
tel(o)-, far, end
troph(i)-, nutrition
trop(i)-, turning
vascul(a)-, vessel
villi-, shaggy
xantho-, yellow
zygo-, yoked together
zoo-, animal, motile
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APPENDIX I - SIGNIFICANT FIGURES
(Adapted from Dolphin, W.D. 1992 Biology Laboratory Manual, 3rd Edition, Wm. C. Brown Publishers)
Significant figures are defined as the necessary number of figures required to express the result of a
measurement so that only the last digit in the number is in doubt.
For example, if you have a ruler that is calibrated only in centimeters and want to measure a pine
needle, you will find it is between 3 and 4 centimeters. The definition of significant figures tells you that
you can estimate what fraction of a centimeter (in tenths of a centimeter) the pine needle is and thus
record it as 3.4 centimeters. This indicates that the last digit is only an estimate. You would never write
this as 3.41 cm or 3.40 cm as this would imply a preciseness that did not exist in your measuring
instrument.
However, if your ruler was marked in millimeters and you measured the same pine needle, you would
find that it is between 34 and 35 millimeters. You could then estimate the additional figure in tenths of a
millimeter, making the measurement 34.6 mm or 3.46 cm. In this case, the two decimal places of precision
are appropriate, because with this measuring instrument, it is only the hundredths of a centimeter that is
in doubt.
Thus, the rule to use is, when recording measurements, include all of the digits you are sure of, plus
an estimate to the nearest tenth of the next smaller digit.
CALCULATIONS WITH SIGNIFICANT FIGURES
When converting measurements from one set of units to another in the metric system, be sure not to
introduce greater precision than exists in the original number.
For example, if you have found that something is 4.3 cm long and wish to convert it to millimeters,
the correct answer is 43 mm, not 43.0 mm, because the number of centimeters was known only with a
precision to a tenth of a centimeter, and not a hundredth of a centimeter as 43.0 mm implies.
When performing multiplication or division involving numbers with different levels of significant
figures, the answer should be expressed only with the precision of the number in the calculation that shows
the least number of significant figures.
For example, you want to calculate the weight of 10.1 ml of water and you are given the density of
water as 0.9976g/ml. To get the weight, you multiply the density X the volume. However, the correct
answer would be 10.1 g, not 10.07576 g. Because the water volume measurement is known only to three
significant figures, the second answer conveys a precision that is not justified given the uncertainty of the
water volume measurement.
When performing additions or subtractions, the answer should contain no more decimal places than
the number with the least number of digits after the decimal point.
For example, 7.2 oC subtracted from 7.663 oC gives a correct answer of 0.5 oC not
0.463 oC.
ROUNDING
The rules governing rounding are straightforward for the most part. You should not change the value
of the last significant digit if the digit following it is less than 5. Therefore, 3.449 would round to 3.4 if two
significant figures were required.
If the following number is greater than 5, then you increase the last significant figure by one. Thus,
88.643 would round to 89, if two significant figures were required.
There is some disagreement among scientists and statisticians as to what to do when the following
number is exactly 5, as in 724.5, and three significant figures are required. Some suggest you should
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always round up. Others suggest you flip a coin, rounding up when heads arise and not rounding up when
tails arise. Still others suggest that you round up if the number preceding the 5 is an even number and not
rounding if the preceding number is odd.
APPENDIX II – GRAPHS
(Adapted from Bio. 150 Lab Manual, University of Victoria, 1981).
This section is to help you learn how to organize data into graphs. Graphs generally show
relationships more readily than tables, because the values are related directly at each point. The distance
along the x axis is called abscissa and the distance along the y axis is called the ordinate. Together such x,
y pairs are called co-ordinates. The point where both co-ordinates are zero is called the origin. Figure
AI.1 shows these relationships.
point
y-axis
abscissa
origin
ordinate
x-axis
Figure AI.1 Principals of plotting graphs.
Some General Principles of Plotting Graphs
LABELS
The graph as a whole should be centered on the page. In most cases the graph is placed vertically on
the page. Each axis is indented from the margins of the graph paper in order to center the graph and
leave ample room for the labels on each axis. . Be sure to leave ample margins (at least 1”) on the right
side, the top and bottom. A 1.5” margin on the left hand side will allow for binding space.
The labels on each axis must describe what variable is represented and the units used.
TITLE and FIGURE NUMBER
All graphs must have an explanatory caption under the figure. This caption is more than simply
“what versus what”; it should clearly state what was being measured so that someone can view the graph
and know what was done to get the curve without having to search for and read the appropriate part of
the lab or paper. The caption is placed below the graph, separated from it so as to not interfere with the
axes labels. A figure number should precede the title.
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SCALE
If convenient, use a scale of one unit for each square. Condensed scales (i.e. more than 1 unit/square)
are useful for large numerical values. Expanded scales (less than 1 unit/square) are necessary for minute
values. The scale used on the x-axis need not be the same as on the y-axis, and it is not necessary to start
either scale from zero, but consider what is being presented; the zero may be needed for interpretation. If
using the zero puts your line in the upper part of the graph and leaves a large blank space, you may
condense the axis by breaking it with two short slanted lines, like this:
PLOTTING
Usually there are two variables to be considered (1) the independent variable e.g. time or any other
variable that is regular and not affected by the experiments; this is plotted on the horizontal X axis
because it provides a nice regular base for the graph and (2) the dependent variable, something that
changes in a way that depends or is related to the independent variable e.g. change in weight or rates
measured at different time periods after birth. The dependant variable is placed on the Y axis.
BROKEN LINE GRAPH
After the points have been located on a graph, it is customary to draw a straight line from each point
to the adjacent point for the "curve" which shows the fluctuations in the value of the dependent variable
(Figure AI.2).
Table A1.1
3
8
6
12
14
19
17
14
20
10
30
25
(g)
3
4
9
12
18
22
27
31
34
39
Y
Weight (g)
weight
X
Age (days)
Y
20
15
10
5
10
20
age
30
(days)
40
X
Figure AI.2 Broken line graph of data in Table AI.1
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SMOOTH LINE GRAPH
If all the points fall on a smooth curve, it is advisable to draw such a curve as evenly as possible
(Figure AI.3).
Y
Table A1.2
30
5
10
16
22
28
35
5
10
14
17
19
20
25
(g)
Y
Weight (g)
weight
X
Age (days)
20
15
10
5
10
20
age
30
(days)
40
X
Figure AI.3 Smooth Curve line of data in Table AI.2
SMOOTHING
Most experimental results in biology are apt to show little irregularities which make it impossible to
draw a smooth curve through the points. The larger the sample used to determine each point, the better
the chances of a smooth curve. An alternative to the broken line or curve which goes through each point
is to draw a smooth-flowing curve in such a way that it passes through the midst of the scattering points
and follows their general trend without necessarily passing through most of them (or even any of them). It
should leave the points well distributed, some above and some below the line (Figure AI.4). This process
(called smoothing) is often over-used. It should only be used when one is reasonably certain that the small
irregularities in the data are due to unavoidable experimental error or chance variation. Otherwise,
misinterpretation of the data may result.
Y
30
weight
(g)
25
20
15
10
5
10
20
age
30
(days)
40
X
Figure AI.4 Smoothed curve
In the case of data points that appear to fall primarily in a straight line relationship, one can either
draw this as a broken line or as a straight line that falls uniformly through the midst of the points. Again
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this latter method should only be done when the irregularities are known to be due to experimental error
or variation.
It should be noted that in fitting a smooth curve or a straight line of data points (Figures AI.3 and
AI.4) one is essentially making a mathematical statement that the data fits the equation for that curve. On
the other hand, in a broken line curve (Figure AI.2) no mathematical relationship is implied to exist, and
nothing is known about the intermediate values.
10
5
average
height
(m)
BAR GRAPHS - used to compare non-related variables
maple
birch spruce
elm
Type of Tree
Figure AI.5 Height of different species of trees in a forest.
Bar graphs are useful for the comparison of variables which are similar but are not necessarily related
to each other (Figure AI.5). Usually a space is left between adjacent bars in order to facilitate the
identification of the bar by its label and to emphasize the fact that the variables are not related and do not
affect one another.
Bar graphs are also used to show differing proportions of things under a range of conditions, e.g.
under different light conditions different proportions of aphids develop wings.
Percentage of
Winged Aphids
100
Wingless
Winged
50
8
Hours
10
of
12
Daylight
14
Figure AI.6 Proportion of aphids developing wings under different light conditions.
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HISTOGRAMS - used to show relationships between classes of related data
The histogram is like a vertical bar graph with no spaces between the bars because the data is of
a continuous nature and has merely been broken down into groups or classes, e.g. the height of boys (ages
12-18); the class size here is 0.5 feet; the frequency occurrence is indicated on the vertical axis.
frequency
20
15
10
5
4.0 4.5
5.0 5.5
Height
6.0
6.5
(feet)
Figure AI.7 Height of boys between ages 12 and 18.
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APPENDIX III - BIOLOGICAL DRAWINGS
Time and again, in your career as a biologist, you will be asked to make a "proper" biological
drawing. Students frequently protest that they “can't draw”, but it is a misconception that you must be an
artist to produce a proper drawing. Good biological drawings do not require artistic ability, but they do
require careful attention to details and a good understanding of the material in question.
A biological drawing is made so that you can show someone else what you have seen and
observed. It should be:
a. clear and neat
b. accurate in size and proportion
c. properly titled and labeled
The following guidelines will help:
1.
First observe and study the object as carefully as possible. Using the lab exercise as a guide, make
sure you know what every required structure is and where it is.
2.
Draw directly from the specimen and complete all drawings in the lab.
3.
Use plain white paper, a sharp, hard pencil (3H or 4H) and a good eraser. Draw lightly at first so
that unwanted lines can be erased easily. Do not use soft pencils, ink or ball-point pen for drawing
or labeling.
4.
Decide how large to make your drawing. It should occupy most of the center of the page with
adequate space left around it for the labels, title and scale bar. Be sure to leave ample margins (at
least 1”) on the right side, the top and bottom. A 1.5” margin on the left hand side will allow for
binding space. Thumbnail size is not acceptable. Remember to leave space for labels.
5.
Mark out lightly the length and width to be occupied by the figure. Estimate the proportional sizes
of some of the component parts in relation to the entire figure and mark these out lightly in the
drawing. Then outline the entire figure in light lines.
6.
Draw in the major features, fill in the details. Once you are satisfied with the drawing, strengthen
the lines and make them bold. Erase any unwanted and unneeded lines. Avoid sketchy or broken
lines.
7.
Do not shade the drawing. If you feel that darkening a part of the drawing will be helpful, use
stippling to highlight these areas.
8.
Show the actual size of the specimen by putting a calibration or scale line next to your drawing.
This line can be of any length but must provide information to the observer about the specimen's
(not the drawing's) true size. It is usually expressed in millimeters (or in microns if the specimen is
very small). Drawings without some indication of size are not at all useful.
9.
Labels are printed in pencil using small or lower case letters. Align the end of each label line with
the one above it so that the labels appear neatly in a list. Put the labels on the right hand side, if
possible. If you have a large number of labels, it is better to also label on the left hand side than to
crowd all the labels together on the right. Use your common sense; make your labeling easy for the
viewer to read and interpret. Put labels at the end of the lines, never on top. Label as accurately as
possible, with attention to the proper use of plurals.
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l0.
Connect the labels to the drawing with straight lines drawn with a ruler. These lines should be
parallel and horizontal wherever possible. Label lines must never cross and should be angled or
forked no more than once. Label lines never have arrows at the ends. Be careful to be sure each label
line reaches its target, hastily drawn label lines often fall a millimeter or two short of the structure
they are supposed to indicate. To observe all these guidelines means you must carefully plan the
placement of your labels and label lines.
11.
At the top right of your drawing put your name. At the top left you should place the complete
taxonomic hierarchy of the specimen being observed. This classification may be found in the lab
outline, in your text or on the blackboard. Be sure that you use proper format when writing scientific
names.
12.
At the center bottom of the drawing place the figure number and title of the drawing, printed in
pencil. This should state:
1. what you have drawn (the name of the organism)
2. the magnification of the drawing
3. the type of preparation (i.e., whole mount, cross section, smear, etc. in the case of microscopic
specimens on slides), type of stain if used, or the view of the drawing (i.e., dorsal view, lateral view,
etc. in the case of larger, whole plants or animals. ).
13.
Magnification of the drawing is calculated as follows:
Magnification of the drawing =
Drawing size
Actual size
This magnification is usually rounded off to the nearest level of accuracy that you have been able to
measure. For example, if the calculation gives a magnification of 838.8, and you feel that you can
measure to€two figures of accuracy you would put X 840 on your drawing.
APPENDIX IV - TABLES
As with biological illustrations, there is a general set of rules that apply to tables used to summarize
biological data.
1. Tables must be clear and concise. After you have recorded the results of an experiment,
determine the most logical and understandable way to present the data in tabular form.
This may involve a few attempts on scrap paper before you decide which is best.
It is often necessary to organize and summarize the data.
2. Each table should have a number and must have a title that completely explains the data it
presents. The table number and title is placed at the top of the table and separated from it by two
narrow ruled lines. Be sure to leave ample margins (at least 1”) on the right side, the top and bottom. A
1.5”
margin on the left hand side will allow for binding space.
Place the table vertically on the page.
3. Column headings are placed under the double ruled line and separated from the body of the
table by a single ruled line. Units of measurement are placed in the column heading and not repeated
in the body of the table (or the title)
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4. The data to be presented is organized in neat columns under each appropriate heading.
Generally, the data is arranged so that you read it horizontally; that is, you read across
the table, not up and down.
5. Vertical and horizontal lines are not used in the body of the table. A neat, well organized
table has the information aligned in rows and columns. Lines here are unnecessary.
However, a final horizontal line is used to complete the table.
6. If anything within the table needs explanation, use an asterisk and a brief footnote below
the final horizontal line of the table.
Here is an example of proper table format :
Table 5.1
Characteristics of Bacteria found in the Mixed Smear slide
Cell Type
Cocci
Length (units)
Gram-Staining Properties
Diplococci
Streptococci
Staphylococci
Bacilli
Spirilli
___________________________________________________________________________________
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ACKNOWLEDGEMENTS
The contents of this laboratory manual have meandered their way to Mount Allison by a variety of
pathways. We acknowledge the contributions made by various undergraduate and graduate schools we
ourselves attended. Moreover, there is a genealogy of past Mount A personnel who have left their
contributions, many of which have since evolved. In addition, this presentation owes a debt to previous
Mount Allison students whose feed-back on many laboratory exercises has lead to significant improvements
and is much appreciated. Some laboratories have parts which are adapted, compiled and condensed from
the following sources:
Abramoff, P. and R.G. Thomson. 1972. Laboratory Outlines in Biology-II; W.H. Freeman and Company, San
Francisco.
Acadia University. 1982. Unpublished Introductory Biology Laboratory Outlines, Wolfville, Nova Scotia.
Arms, K. and P. Camp. 1982. Biology Laboratory Manual to Accompany "Biology". Second Ed.; Saunders, College
Publishing, New York.
Audesirk, G. and T. Audesirk. 1989. Biology. Life on Earth, 2nd Edition. MacMillan Publishing. New York.
Campbell, Neil A. 1990. Biology. 2nd Edition. The Benjamin/Cunnings Publishing Company, Inc.
Dean, H.L. 1978. Laboratory Exercises, Biology of Plants. Fourth Edition; Wm. C. Brown Company Publishers,
Dubuque, Iowa.
Enger, E.D., A.H. Gibson, J.R. Kormelink, F.C. Ross, R.J. Smith and C.H. Borgman. 1979. Concepts in Biology.
Laboratory Manual, Second Edition, Wm. C. Brown Co. Pub., Iowa.
Goodenough, J.E. 1987. Laboratory Collection for Campbell's Biology. Benjamin/Cummings Publishing,
California.
Helms & Helms. 1989. More Biology in the Laboratory. Worth Publishers, Inc. New York.
Keeton, W.T. and J.L. Gould. 1986. Biological Science. Fourth Edition; W.W. Norton & Company, New York.
Kimball, J.W. 1982. Biology. Fifth Edition, Addison-Wesley Pub. Co., Don Mills, Ontario.
Lytle/Wodsedalek. 1990. General Zoology Lab Manual. Eleventh Edition: Wm. C. Brown, Dubuque, Iowa.
Mader, S.S. 1985. Laboratory Manual. Evolution, Diversity, and the Environment. Wm. C. Brown Publishers,
Dubuque, Iowa.
McCourt, Richard M. 1988. Laboratory Manual to Accompany Biology, Wessels/Hopson. Random House. New
York.
Saunders, G.P. 1981. Biology, the Science of Life, Laboratory Manual. Scott, Foresman and Company, Glenview,
Illinois.
University of Victoria, 1981-82, Biology 150 Lab Manual.