BIOL IF90 December 12, 2011 Page 2 of 17
PART A - Multiple Choice Section
1. Which of the following is an important feature of carbon and that makes life possible?
A. Carbon can form a maximum of 8 covalent bonds.
B. Carbon can form a maximum of 6 covalent bonds.
C. Carbon can form a maximum of 4 covalent bonds.
D. Carbon can form a maximum of2 covalent bonds.
E. None ofthe choices are possible for carbon.
2. Water held behind a dam would best reflect __ ----:
A. potential energy
B. kinetic energy
C. chemical energy
D. heat energy
E. mechanical energy
3. A chemical reaction that has a positive AG is correctly described as
4. Which of the following is NOT a product of the light reactions of photosynthesis?
D. carbon dioxide
E. energy intermediates
5. During noncyclic linear electron flow of the light reactions of photosynthesis, which molecule is
the final acceptor of the high-energy electron?
E. A TP synthase
6. During photosynthesis, the energy given up by electrons as they move through the electron
transport chain is used to
A. produce glucose.
B. fix CO 2.
C. generate an electrochemical H+ gradient across a membrane.
D. oxidize water.
E. boost energy levels of pigment electrons.
BIOL IF90 December 12,2011 Page 3 of 17 7. What is the main role of the pigment molecules within the antenna or light-harvesting complex?
A. Oxidize water and release oxygen to the reaction center chlorophyll.
B. Absorb photons and transfer light energy to the reaction center chlorophyll.
C. Synthesize NADPH.
D. Pass electrons to the electron transport chain and then to NADPH.
E. Increase H+ concentration in the stroma.
8. What was the most significant conclusion that Gregor Mendel drew from his experiments with
A. There is considerable genetic variation in garden peas.
B. Traits are inherited in discrete units, and are not the results of "blending."
C. Recessive genes occur more frequently in the F 1than do dominant ones.
D. Genes are composed of DNA.
E. An organism that is homozygous for many recessive traits is at a disadvantage.
9. A cross between homozygous purple-flowered and homozygous white-flowered pea plants
results in offspring with purple flowers. This demonstrates
A. the blending model of genetics.
D. a dihybrid cross.
E. the mistakes made by Mendel.
10. Mendel accounted for the observation that traits which had disappeared in the F1 generation
reappeared in the F2 generation by proposing that
A. new mutations were frequently generated in the F2 progeny, "reinventing" traits that had
been lost in
B. the mechanism controlling the appearance of traits was different between the F I and the
C. traits can be dominant or recessive, and the recessive traits were obscured by the dominant
ones in the
D. the traits were lost in the FI due to blending ofthe parental traits.
E. members of the FI generation had only one allele for each character, but members of the
F2 had two
alleles for each character.~.
11. In snapdragons, heterozygotes have pink flowers, whereas homozygotes have red or white
flowers. When plants with red flowers are crossed with plants with white flowers, what proportion
of the offspring will have pink flowers?
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The following statement pertains to the next two questions (#12 and #13). A tall plant is crossed
with a short plant, and the progeny are all intermediate in size between the two parental plants.
12. This could be an example of
A. incomplete dominance.
B. polygenic inheritance.
C. complete dominance.
E. B orC
13. Ifthe intermediate Fl progeny were allowed to self-pollinate, and the F2 progeny were also
int~rmediate in size, but with some variation which followed a "normal" or "bell curve"
distribution, this would suggest
A. incomplete dominance.
B. polygenic inheritance.
C. complete dominance.
D. a strong environmental influence.
14. In certain plants, round seed shape is dominant to wrinkled seed shape.Ifa heterozygous
plant is crossed with a homozygous round seed plant, what is the probability that the offspring
will have wrinkled seeds?
15. The fact that aU seven of the pea plant traits studied by Mendel obeyed the principle of
independent assortment means that
A. none of the traits obeyed the law of segregation.
B. the diploid number of chromosomes in the pea plants was 7.
C. all of the genes controlling the traits were located on the same chromosome.
D. all of the genes controlling the traits behaved as if they were on differmt chromosomes.
E. the formation of gametes in plants occurs by mitosis only.
16. In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes
orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from
cross of a black female and an orange male?
A. tortoiseshell female; tortoiseshell male
B. black female; orange male
C. orange female; orange male
D. tortoiseshell female; black male E. orange female; black male
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17. What is genetic cross between an individual showing a dominant phenotype (but of unknown
genotype) and a homozygous recessive individual called?
A. a self-cross
B. a testcross
C. a hybrid cross
D. an FI cross
E. a dihybrid cross
18. A recessive allele on the X chromosome is responsible for red-green color blindness in
humans. A woman with normal vision whose father is color-blind marries a color-blind male.
Whpt is the probability that a son of this couple will be color-blind?
19. How would one explain a testcross involving Fldihybrid flies in which more parental-type
offspring than recombinant-type offspring are produced?
A. The two genes are linked.
B. The two genes are unlinked.
C. Recombination did not occur in the cell during meiosis.
D. The testcross was improperly performed.
E. Both of the characters are controlled by more than one gene.
20. What does a frequency of recombination of 50% indicate?
A. The two genes are likely located on different chromosomes.
B. All of the offspring have combinations of traits that match one ofthe two parents.
C. The genes are located on sex chromosomes.
D. Abnormal meiosis has occurred.
E. Independent assortment is hindered.
21. A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for
tail length (T). Its genotypeHhTt. Which of the following genotypef' is possible in a gamete from
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22. When crossing a homozygous recessive with a heterozygote, what is the chance of getting an
offspring with the homozygous recessive phenotype?
23. PP = purple, Pp= purple, pp= white. The offspring of a cross between two heterozygous
purple-flowering plants(PP x PP) results in
A. all purple-flowered plants.
B. ''purple-flowered plants and white-flowered plants.
C. two types of white-flowered plants: PP and Pp.
D. all white-flowered plants.
E. all pink-flowered plants
24. Black fur in mic(B) is dominant to brown fur(b).Short tail(T)are dominant to long tails
(I)What fraction of the progeny of the cross BbTt x BBtt will have black fur and long tails?
25. What is the mechanism for the production of genetic recombinants?
A. X inactivation
B. methylation of cytosine
C. crossing over and independent assortment
E. deletions and duplications during meiosis
26. The frequency of crossing over between any two linked genes is
A. higher if they are recessive.
B. different between males and females~'
C. determined by their relative dominance.
D. the same as ifthey were not linked.
E. proportional to the distance between them.
27. A man, who carries an X-linked allele will pass it on to
A. all of his daughters.
B. half of his daughters.
C. all of his sons.
D. half of his sons.
E. all of his children.
BIOL IF90 December 12, 2011 Page 7 of 17
28. Which of the following statementstrue regarding genomic imprinting?
A. It explains cases in which the gender of the parent from whom an allele is inherited affects
expression of that allele. B. Itis greatest in females because of the larger maternal contribution of cytoplasm.
c. Itmay explain the transmission of Duchenne muscular dystrophy.
D. Itinvolves an irreversible alteration in the DNA sequence of imprinted genes.
E.All of the above are correct.
29. The recombination frequency between genA and gene B is20%,,'the recombination
frequency between gene A and gene C is 12%, and the recombination frequency between gene B
and gene Cis 8%. Which is the correct arrangement of these genes?
The following pertains to the next two questions (#30 and #3Drosophila the gene for wobbly
leg, a recessive trait, has two alleles, "w" for wobbly leg and "W" for wild type leg. The gene for blue
nose, a recessive trait, has two alleles, "b" for blue nose and "B" for wild type nose. To begin a
mapping procedure, a cross between WWBB and wwbb was made and the resulting progeny WwBb
were then test-crossed with wwbb. In this test cross the progeny were as follows; 465 wild type, 472
wobbly leg and blue nose, 35 wobbly leg and wild type nose, 28 wild type leg and blue nose.
30. In this example which one of the following genotypes would be described as recombinant?