Name: _____________________________
Honors Biology
Final Exam, Fall 2007
105 points
Part 1: Fill in and short answer section:
Nature of Science and Scientific Inquiry
1.(2) Two tenets of the Nature of Science are “Scientific knowledge is durable” and “Scientific ideas are
subject to change.” Briefly describe a single example from the history we’ve studied (besides the
example given in the essay question) that illustrates both of these seemingly contradictory ideas
Several examples of ideas that both persist AND change would do here: Darwin’s
theory of Natural Selection persists, but has undergone changes from new
knowledge about genetics; Linnaeus’ system of classification is still the backbone
of modern classification, but has undergone modifications to fit modern
knowledge.
2. (3)Briefly describe the differences between a law, a theory, and a hypothesis.
Thirty lashes with a wet noodle if you didn’t get this one!
Law: An evidence-based description of a natural phenomenon.
Theory: An evidence-based explanation for a natural phenomenon.
Hypothesis: A tentative explanation for a specific observation.
3. (2)You hear about a great new herbal pill for treating colds. You decide you’re going to test this product
to see if it’s really effective. You and nine friends all take the pill twice daily as directed on the label
from October until May, which you figure is cold season. You have everyone keep track of the number
of colds they have and how severe they are. At the end of your study, you find that the average number of
colds among your study group was 3.5 per person, each cold lasted an average of 6 days, and the
symptoms were described as “moderate.” You show these results to your favorite biology instructor who
points out that the results mean little because something critical is missing from your study. What should
you have done differently?
The main thing I was looking for here was the lack of a control group. With nothing to
compare these results to, how do we know if they mean anything? It’s the wrong type of
inquiry for answering the underlying question.
/7
Cells and cell structures
1. (16) The diagram to the right shows a plant
cell. Using the hint below, fill in the table with
the name of each cell structure and its
function. The ones that were not on the study
guide are done for you as examples.
Hints:
A: Like a stack of hollow pancakes.
B: Large, membrane-bound sac.
C. Stains darkly with iodine.
D: Contain their own DNA, metabolize sugar.
E: Rigid, made of cellulose
F: Flexible, made of lipids and proteins.
G: It’s green.
H: Network of tubes.
I: Stains more darkly than J.
J: In the middle of the cell, takes up methylene
blue stain.
K: Fluid.
Label
A
Organelle
Function
Golgi Body
Packaging and delivery center for cell products.
B
Central Vacuole
Storage, water regulation, recycling of materials.
C
Leucoplast
Stores starch.
D
Mitochondria
Powerhouses of the cell; produce ATP.
E
Cell wall
Rigid structure that provides support for the cell.
F
Cell membrane
Outer boundary of the cell; controls what goes in and out.
G
Chloroplast
Carries out photosynthesis.
H
Endoplasmic Reticulum
I
Nucleolus
Rough E.R. = site of protein synthesis
Smooth E.R. = site of lipid synthesis
Manufactures ribosomes.
J
Nucleus
Contains DNA; controls cell processes.
K
Cytoplasm
Liquid inside of the cell where much of the chemistry of
life occurs.
/16
2. (3)Melvin, ace biology student, raises a hand in Ms. Fishhawk’s biology class and says, “I wouldn’t call
Hooke the discoverer of cells, considering what he saw and how he described it. I think that credit really
goes to Leeuwenhoek.” Put yourself in Ms. Fishshawk’s shoes and either support or refute Melvin’s
argument using what you know about these two scientists. (Credit is for how well you argue your
response, not whether you support or refute Melvin.)
Support Melvin: Hooke first used the
word “cell,” but only in connection with
the small holes he saw in cork.
Leeuwenhoek explored the cellular world
more thoroughly, first discovered
“animalcules,” and found that every living
thing he looked at had cells (eventually
leading to cell theory).
Refute Melvin: Hooke may have only
looked at cork, but he was the first person
to think of looking at tissue on the
microscale. His discovery is what inspired
Leeuwenhoek to make his own
microscopes and led to Leewenhoek’s
discoveries.
3. (2)Redi, Spallanzani, and Pasteur all set up experiments to test the theory of Spontaneous Generation.
Why was Pasteur successful at refuting the theory while Redi and Spallanzani were less convincing to
the scientific community?
Here I wanted some mention of experimental design – Redi and Spallanzani were
both criticized for not allowing air into their samples. What if air contained a necessary
“vital force” to cause spontaneous generation? Pasteur was the first to come up with a
design for a flask that allowed air in but prevented microbial contamination.
Diversity and Classification
1.(1) Both Linnaeus and Buffon worked on systems of biological classification. What was the fundamental
difference between their approaches?
Buffon thought only a natural system of classification was worth searching for. Linnaeus
admitted his system was artificial and a natural one would be ideal, but his system was
practical.
2. (1)From its inception, Kingdom Protista has been problematic. Why?
Protista is a polyphyletic group, so it does not reflect any natural relationship. From
the beginning it was kind of a “catch-all” category, originally for all unicellular
organisms (including prokaryotes), and later for anything that didn’t fit in the other
kingdoms.
3. (2)Name the three Domains of living things and their basic characteristics. Then list the four Kingdoms
within the one domain to which we humans belong.
Domain Archaea: prokaryotic domain containing unicellular extremophiles.
Domain Bacteria: prokaryotic unicellular organisms with a wide range of roles.
Domain Eukarya: eukaryotic multi- or uni-cellular organisms. Kingdoms are Protista,
Plantae, Fungi, and Animalia.
/9
4. (8)Buster and Bitsy are lab partners in Ms. Fishhawk’s biology class. In one lab, they must look down a
microscope and identify protists. Bitsy is writing down descriptions while Buster is looking up the
organisms in a textbook and identifying them. Help these two students match their descriptions with the
identification.
Bitsy’s descriptions:
Buster’s categories:
A. Fast-moving, torpedo-shaped, and covered in cilia. The
label on the jar says “Paramecium.”
__E__ Green algae
B. Multicellular, photosynthetic, has red pigments instead
of chlorophyll.
__B__ Red algae
C. It’s fast-moving, has a flagella, has no cell wall, but it
does have chloroplasts. It seems to be eating bacteria.
__H__ Brown algae (Stramenopiles)
D. It’s a small thing with a flagella in the middle that
makes it spin in the water. Seems to be photosynthetic.
__G__ Diatoms (Stramenopiles)
E. Ms. Fishhawk says it’s Volvox. It’s small, green, singlecelled photosynthetic organisms that form into a ball__D__ Dinoflagellates (Alveolates)
shaped colony. I think it has cell walls.
F. It’s a squishy-looking single-celled organism, no
__A__ Cilliates
symmetry, no chloroplasts. It extends pseudopods to
catch and eat things.
__F__ Amoebozoans
G. These are pretty little single-celled things with glasslike silica shells. They photosynthesize with some kind
__C__ Euglenozoans
of brown pigment.
H. This is a multicellular thing that looks like seaweed.
The cells have cell walls, and it uses brown pigments to
photosynthesize.
Genetics
1. (2) The following sequence represents one side of a strand of DNA. Below it, write in the matching
strand:
T A
A
T
T
G
A
C
T
A
A
C
T
G
A
T
T C
A
G
T
G
A
C
2. (2) If the following “strand” of DNA is the sense (or template) strand, write in the mRNA sequence that
is made from it:
A T
U
A
T
C
G
A
G
C
C T
G
A G
A
U
A
T
A
U
A
U
C
3. (2) The sequence below represents a strand of mRNA. Using the codon table provided, find the start
codon and write in the amino acids that are coded for. Stop at the stop codon. (If you don’t find a
stop codon, something’s wrong.)
U
A
U
Start
G
G
G U
Glycine
A
G
Serine
C
U
A
A U
C
Stop
/14
4. (4) Imogene, another student in Ms. Fishhawk’s class, has flat feet, and asks the class why she has flat
feet when her parents do not. Ms. Fishhawk notes that flat feet are the result of a recessive allele, which
she labels f. Melvin steps to the board and quickly works out a Punnett square showing how Imogene
inherited her flat feet. In the space below, fill in Melvin’s diagram:
Mom’s genotype ___Ff____
Dad’s genotype: ___ Ff____
Imogene’s genotype: ____ ff____
Punnett square:
F
f
F
FF
Ff
f
Ff
ff
Imogene
5. (8) Some people have bent little fingers, while others have straight little fingers. If you hold your hands
side by side, palms up, with little fingers side by side, you can see if you have straight little fingers (tips
are parallel) or bent little fingers (tips bend away from each other). This trait is controlled by a single
gene which has two alleles: the dominant allele and the recessive allele.
Sally has straight little fingers. Sally has a twin brother, Simon, who has bent little fingers. Sally’s parents
also have bent little fingers. Sally is married to Steve, who has straight little fingers. Their first two
children, Sadie and Sam, both have straight little fingers.
In the space below, draw a family tree for these people and indicate the genotypes of each person. You
must determine which is the dominant trait: bent or straight little fingers. Use F and f as your symbols in
the genotypes. There is one genotype that will be uncertain.
Mom
Ff
Simon
F?
Dad
Ff
Sally
ff
Steve
ff
Sadie
ff
Sam
ff
Bent little fingers must be dominant (F) and straight must be
recessive (f), because Sally has straight fingers while her parents
have bent fingers. That can only happen if her parents are
carriers for the trait (so they don’t show it, but can pass it on) and
Sally inherits a recessive allele from both of them.
/12
6. (5) Fiona is red-green color blind. This kind of color blindness is a recessive X-linked trait. Her husband,
Angus, has normal vision. For each of the questions below, show your work by drawing a Punnett square
or a family tree that includes genotypes (you need just one Punnett square or family tree for all four
questions). In this question, carrier refers to someone who has one recessive and one dominant allele
(that is, has the allele and can pass it on to their own children, but does not show the trait).
XC
y
Xc
Xc XC
Xc y
Xc
Xc XC
Xc y
a. What are the chances that a son of their could be color blind?
100% -- all of the boys are color-blind (boys always get their
X chromosome from their mother)
b. What are the chances that a daughter of theirs could be color blind?
0% -- none of the girls can be color blind (girls all get one normal
X from their father)
c. What are the chances that a daughter of theirs could be a carrier for color blindness?
100% -- all girls will get an affected X chromosome from their mother.
d. What are the chances that a son of theirs could be a carrier for color blindness?
0% -- a boy can never be a carrier for an X-linked trait, since he only has one X
chromosome.
7. (5) Watson and Crick used data discovered by Oswald Avery, Ernest Chargaff, and Rosalind Franklin
as they developed their model of the structure of DNA. List the contributions made by each of the
three scientists that informed the model that Watson and Crick developed.
Avery was the scientist who identified DNA as the hereditary molecule.
Chargaff created Chargaff’s rule: that A and T always pair, C and G always pari.
Franklin’s X-ray crystallography photograph suggested a helical structure, probably a
double helix.
Watson and Crick knew from these scientists that DNA must control traits. Chargaff’s
pairing rule suggested that A and T were always paired, as were C and G. This supported
the idea of a double helix – two intertwined molecules with the bases paired across from
each other.
/10
Evolution
1. (6) In the 1950s a Florida theme park began a new promotion to attract visitors from New England.
Ads were published in New England newspapers saying that the park would give away free baby
alligators to visitors if they booked a visit of at least three days between March and October at one of
the resort hotels. Thousands of families took up the offer and carried their baby alligators back home.
By the following spring, most of the pet alligators were too large to keep at home. Many people simply
released the alligators into local rivers and streams. Newspapers warned against this, predicting that the
alligators would naturalize and become a problem. However, five years later the rivers were still
alligator-free. Newspaper reporters in New England, none of them well-versed in evolutionary biology,
offered explanations for the lack of alligators in the rivers. Read their explanations below and
determine whether any are valid, using what you have learned about population genetics and evolution.
Then explain why you consider each statement valid or invalid.
a. Adaptive radiation is responsible for lack of alligators in the rivers. The rapid change in environment
for these creatures caused new selective pressures. Most gathered into small, isolated populations
where change is more rapid. The alligators needed new traits to survive, and developed them over the
first winter. Most of them learned to hibernate in the winter, and to live on the land and forage in the
woods, and these were the most successful.
Invalid: While change is rapid in small populations, “rapid” generally means
tens of thousands instead of millions of years. Selection that produces
adaptation over time is only going to happen if there are survivors from each
generation. If the environmental change is too rapid, the organisms will die.
b. Alligators encountering their first New England winter were chilled, and had to change their habits to
survive. They learned to move rapidly to stay warm. Those that exercised the most developed warmer
body temperatures, and they passed their developed warm-bloodedness on to their offspring. The
exercise also changed their body shape, so their offspring looked less like alligators, and so most
people don’t recognize them when they see them.
Invalid: No matter how much the alligators exercise and build up muscle mass, even
if they could keep their body temperatures up (which they cannot, since they have
no fur or feathers for insulation), they cannot pass acquired muscularity on to their
offspring.
c. Alligators brought from Florida to New England experienced an environmental change that was so
rapid there was no time to adapt. Harsh, cold winters killed the released alligators, and consequently
they weren’t able to pass any traits on to their offspring, since none lived long enough to have
offspring.
Valid: If the environmental change is too rapid, a population will most likely go
extinct.
/6
2. (3) Both Lamarck and Darwin developed theories of organic change. What are the fundamental
differences between Lamarck’s model of progressive development and Darwin’s model of natural
selection? Why was Darwin’s model later accepted by science while Lamarck’s was not?
Lamarck’s theory relied on spontaneous generation to put new organisms on the
“evolutionary escalator,” and the inheritance of acquired characteristics to cause
them to change over time. Lamarck’s theory was progressive and goal-oriented.
Darwin’s theory relied on natural variation in populations. Selection favored certain
variants over others, and those with favorable variations tended to survive and
reproduce over time. Experiments to test the inheritance of acquired characteristics
refuted this idea, as did the rise of modern genetic science. Genetics supported
Darwin’s model by showing that traits were caused by genes (not by blending of
liquid factors), and that organisms that survived and reproduced each generation
passed their genes on to their offspring.
Ecology
1. (3) The food chain in the illustration below is taken out of an activity book for elementary teachers that
is published by the National Science Teachers Association Press. The publishers will soon receive a
letter from your fearless leader complaining about the misconceptions perpetuated by the diagram.
Explain what is wrong with the diagram and sketch in the corrections that should be made.
The diagram showed something like this, in pictures:
grass mouse snake hawk
A food chain is a model of energy flow from one trophic level to another. The biggest
error in this diagram is the arrows: they’re pointing the wrong direction, and in doing so
they’re saying that energy passes from the hawk to the snake to the mouse and to the
grass. But since grass doesn’t eat mice and mice don’t eat snakes and snakes don’t eat
hawks, this cannot be correct. The arrows need to be reversed to show a proper food
chain.
There was coloring page for the same activity which showed the same “food chain” in a
circular pattern, suggesting that energy cycles – which it does not.
NSTA will be hearing from me.
/6
2. (5) Edward O. Wilson used the acronym “HIPPO” to describe the threats to biological diversity.
Briefly describe the threats posed by each of these HIPPO factors:
The minimum of concepts I wanted to see:
a. Habitat loss
Loss of habitat takes away food sources and nesting sites, severely limiting populations.
b. Introduced species
Non-native species may out-compete native species, since they often have no natural
predators in the new environment.
c. Pollution
Pollutants can kill organisms outright, or reduce their ability to reproduce.
d. Population, human
Humans destroy natural habitats to build houses, farms, shopping malls, roads, etc. The
more humans, the more destruction.
e. Overconsumption
Humans must use natural resources to survive. When we overconsume, we use natural
resources that we don’t really need, and increase environmental destruction.
/5
Essay portion (20 points):
Choose one of the following questions to answer in class. Write 1-2 pages on this subject (extra paper is
provided if needed). Be sure to include historical events and scientific information in your response. The
points will be divided between:
• Historical accuracy (8)
• Scientific accuracy (8)
• Tying historical events together to create a convincing argument. (2)
• Did you answer the question? (2)
1. Many evolutionary biologists reject the use of comparative terms such as higher and lower, or
primitive and advanced, when describing and comparing groups. Such comparisons are value-laden
and may mislead readers into misconceptions about evolution. Discuss the social origins of these
hierarchical terms, and what misconceptions they can lead someone into who is not familiar with the
Modern Synthesis theory of evolution. Then discuss Whittaker’s 5-kingdom system diagram from the
handout. Does the diagram have hierarchical evolutionary implications? How could the diagram be
drawn so that it does not suggest progressive evolution?
2. A little more than a century ago, women wore bird parts or entire birds on their hats and wore fur coats
as a sign of affluence. In addition, songbirds were hunted and sold in public markets for food. Today,
many people view the wearing of animal fur and animal parts as cruelty, and most Americans are
repulsed by the idea of eating sparrows or robins. Discuss the roles that science and society played in
these changes of thought. Include an explanation of the Tragedy of the Commons concept. Then
choose another biological “commons” today that is threatened by over-exploitation, and discuss the
roles that science and society are playing in the conservation or preservation of that “commons.”
3. Hereditary factors were once thought to be liquid factors carried in the blood. Mendel introduced the
idea of hereditary factors as individual particles that control individual traits in an organism, such as
flower color or plant height. With the discovery of the relationships between genes, proteins, and
enzymes, this concept has changed dramatically. Further, Mendel established three laws of heredity
which are still in use in textbooks today, but are apply to different structures than Mendel proposed.
Discuss how discoveries in the 20th century led to the modern concept of the gene and new
understandings of the laws of heredity. Then discuss how these illustrate both the durability and
tentativeness of scientific knowledge.