GENERAL ZOOLOGY LECTURE EXAM 2. FALL 2006. NAME ________________
1. Both members of a pair of homologous chromosomes are:
a. similar in size, in shape, and carry the same genes
b. identical in the sequence of their bases
c. found in gametes
d. linked to one another by a structure called a centromere
e. linked to one another by a structure called a centriole
2. How many chromosomes are present in a human somatic cell during anaphase?
a. 23
b. 46
c. 69
d. 92
e. 184
3. On the leading strand, DNA elongates in the ___________ . On the lagging strand, DNA
elongates in the _________.
a. 3’ to 5’ direction, but only in relatively short stretches; 3’ to 5’ direction.
b. 3’ to 5’ direction; 3’ to 5’ direction, but only in relatively short stretches
c. 5’ to 3’ direction, but only in relatively short stretches; 5’ to 3’ direction,
d. 5’ to 3’ direction; 5’ to 3’ direction, but only in relatively short stretches
e. 5’ to 3’ direction, but only in relatively short stretches; 5’ to 3’ direction, but only in relatively short
stretches.
4. In order for DNA polymerase to function on a single strand of DNA, it requires a short piece of
ribonucleic acid referred to as a:
a. mRNA
b. tRNA
c. rRNA
d. small subunit of the ribosome
e. primer
5. During which phase do the centrosomes of a cell duplicate?
a. G1 of interphase
b. S of interphase
c. G2 of interphase
d. prophase
e. telophase
6. In animal mitosis, the cleavage furrow forms as the result of the action of which of the following?
a. constriction of a ring of actin microfilaments
b. addition of tubulin subunits to microtubules
c. removal of tubulin subunits from microtubules
d. the interaction of a kinetochore and a microtubule
e. movements of the spindle apparatus
7. During meiosis, homologous pairs of chromosomes assort randomly into daughter cells. This
means that:
a. The combination of maternal and paternal chromosomes will vary among daughter cells.
b. Daughter cells will always contain either maternal or paternal chromosomes, but not a mix of
both.
c. Daughter cells will always contain a mix of maternal and paternal chromosomes, but never just
maternal or just paternal.
d. Daughter cells will always contain one maternal and one paternal chromosome from each
homologous pair.
e. In any right triangle, the area of the square whose side is the hypotenuse is equal to the sum of
the areas of the squares of the other two sides.
8. When unequal crossing over occurs, what will you find in the resulting cells?
a. half will be missing a chromosome, half will have an extra chromosome
b. half will experience deletions, the other half will experience duplications
c. all will have stop codons inserted in locations where they do not belong
d. all will have frameshift mutations
e. none of the above will occur
9. The _______ of tRNA is ____________ to the ________ of mRNA.
a. codon, identical, anticodon
b. codon, complimentary, anticodon
c. anticodon, identical, codon
d. anticodon, complimentary, codon
e. knee bone, connected, thigh bone
10. During crossing-over, non-sister chromatids exchange DNA at locations called:
a. chiasmata
b. synapsis
c. centromeres
d. kinetochores
e. equatorial plate
11. What was the most significant result Gregor Mendel drew from his experiments with pea plants?
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 F1 than do dominant genes.
d. Genes are composed of DNA.
e. An organism that is homozygous for many recessive traits is at a disadvantage.
12. If an organism's 2n number is 12, how many chromosomes will be present in each daughter cell
at the end of meiosis II?
a. 2
b. 6
c. 12
d. 24
e. 48
13. Can Mendel’s law of independent assortment be expected to hold true when the two sets of traits
being examined are located on two different pairs of chromosomes?
a.
yes
b.
no
c.
there is no way to tell
14. Which of the following would be the best example of microevolution?
a. An animal species that was once large, like the Wooly Mammoth, evolves over time into a
species that is very much smaller than the original.
b. A structure like a well-developed tail evolves over time into a much smaller structure, such as the
vestigial tailbone found in humans.
c. In a certain species of animal, an evolutionary change occurs in the structure of a microscopic
organelle, such as the mitochondrion.
d. Some sort of evolutionary change, such as the evolution of eyes, occurs in a species that is
microscopic in size, like a tiny roundworm found in the soil.
e. The frequency of a recessive allele for albinism in a population of Bald Eagles increases by 15%
over the course of 100 years.
15. Darwin was influenced by Lyell’s concept of uniformitarianism. What does uniformitarianism
refer to?
a. The belief that events that affect an organism during its lifetime can cause changes that are
passed along to the organism’s offspring.
b. The belief that events that affect an organism during its lifetime generally DO NOT cause
changes that are passed along to the organism’s offspring.
c. The belief that natural processes observable on Earth today, like erosion, were probably
physically the same in the geologic past.
d. The believe that natural processes observable on Earth today, like mountain-building, probably
behaved according to a different set of physical laws in the past.
e. The belief that the human population tends to be held in check by a variety of factors, including
war, disease and starvation.
16. Darwin’s most influential work, “The Origin of Species” was first published during which time
period?
a. the latter half of the 1700’s
b. the earlier half of the 1800’s
c. the latter half of the 1800’s
d. the earlier half of the 1900’s
e. the latter half of the 1900’s
17. One of the most important ideas in Darwin’s work was the concept that “all organisms have
descended, with modification, from ________________ .
a. more complex ancestors
b. simpler ancestors
c. common ancestors
d. rare ancestors
e. monkeys
18. The other arguably most important idea in Darwin’s work was the concept that the “chief agent
of evolution is the action of natural selection on ______________ “
a. the fittest organisms
b. weak organisms
c. extinct species
d. variation
e. rare recessive alleles
19. Which of the following has been used to suggest that Archaeopteryx was a poor flier, compared
to modern birds?
a. the structure of its sternum (breast bone)
b. the fact that its wings were very small relative to modern bird wings
c. the claws on its wings, which must have allowed it to climb trees, from which it could then launch
itself and glide to the ground
d. Archaeopteryx had no tail.
e. None of the above. All indications suggest that Archaeopteryx was an excellent flier.
20. Both bumblebees and hummingbirds have wings that move in much the same way, allowing
them to hover in midair. The wings of the hummingbird are modifications of its bony forelimb,
something that does not exist in the bee or in its insect ancestors. The wings of the bumblebee are
modifications of its shell-like chitinous exoskeleton, something that does not exist in the
hummingbird or its vertebrate ancestors. The relationship between the wings of these two animals
is an example of:
a. homology
b. ontogeny
c. analogy
d. phylogeny
e. self-directed evolution
21. I examine a population of wildebeest and notice that for one particular trait, horn-length, the
population does not exhibit Hardy-Weinberg equilibrium. Which of the following could easily explain
my observation.
a. The population of Wildebeests I examined was very large.
b. Some natural selection for length of horn could be taking place.
c. No mutations were occurring in the horn-length alleles.
d. There was an absence of gene flow (migration).
e. Wildebeests with long and short horns were mating with one another randomly.
22. What name is given to the process that restores the diploid number of chromosomes following
reductive division?
a.
mitosis
b.
meiosis
c.
cytokinesis
d.
anaphase
e.
fertilization
23.
While modern birds have no teeth, their ancestors did. In the embryonic development of modern
birds, stages can be observed where teeth are present. The teeth are lost later in development.
This is an example of:
a. the inheritance of acquired characters
b. self-directed evolution
c. convergent evolution
d. differential survival and reproduction
e. ontogeny recapitulating phylogeny
24. When first formed, the mRNA molecule may contain bases that will be removed during the
editing process. Which of the following best describes this process?
a. introns are removed, and exons are left
b. exons are removed, and introns are left
c. junk DNA is removed, and introns and exons are left
d. introns and exons are removed, and coding RNA is left
e. exons are removed, and coding DNA is left
25. You are genetically unique compared to your biological siblings (unless you happen to be an
identical twin). This uniqueness is a result of:
a. random fertilization
b. crossing over
c. independent assortment of chromosomes
d. both A and B
e. A, B, and C
26.
The main reason inbreeding is considered to be such a bad idea is that it:
a. causes an increase in the number of individuals who are homozygous rare recessive alleles
b. causes an increase in the number of individuals who are heterozygous for rare recessive alleles
c. causes a decrease in the number of individuals who are homozygous for rare recessive alleles
d. causes an increase in the number of individuals who are homozygous for rare dominant alleles
e. causes mutations that can be deleterious to the organism.
27. Is the increase in numbers of pesticide-resistant insects considered an example of
evolution?
a. Yes, because anything that involves a change over time is considered evolution.
b. Yes, because there has been a change in allele frequency.
c. Yes, because insects pass these traits on to their offspring.
d. No, because the non-resistant and the resistant individuals are still the same species.
e. No, because not enough time has passed since the invention of pesticides for evolution
to have taken place. Evolution requires millions of years.
28. The incredible display of male peafowl tail feathers can be explained by which of the following?
a. the sexy son hypothesis
b. the handicap principle
c. zuk’s assessment hypothesis
d. all of the above
e. none of the above
29. An instinctive behavior is:
a. learned
b. unlearned
c. one that increases the fitness of an organism
d. one that decreases the fitness of an organism
e. none of the above
30. Biston betularia is often used as an example of:
a. adaptive radiation into unfilled niches
b. the evolution of an individual as a result of changes in the environment
c. changes in allele frequency due to changes in natural selection pressures
d. the risks of too much asexual reproduction
e. the risks of not enough asexual reproduction
31. 10 points. SHOW YOUR WORK.
In M&Ms, melting in your mouth, not in your hand, is determined by the hard candy shell, a
dominant trait (MM or Mm). The messy and unfortunate absence of the hard candy shell is
determined by a pair of recessive alleles (mm). In a population of 100 candies, 49 individuals lack
the hard shell, the remainder possess it. Assuming the population is in Hardy-Weinberg
equilibrium, how many of the candies are homozygous dominant MM?
32. Use the table provided to determine the amino acid sequence coded for by the following DNA
sequence. (Assume that the strand you are given is the coding strand.) 10 points. Show your
work.
TACGAACTTGGGTCC
ANSWER:
ESSAY QUESTIONS
Choose one of the following, and write a well-organized essay answer. 20 points.
a. Use Mayr’s facts and inferences to explain the evolution of cave organisms that results in such
a high level of albinism. Clearly state each of Mayr’s facts and inferences, and explain how
each relates to the cave organisms.
b. Describe the steps in protein synthesis, beginning with the DNA in the nucleus, and ending with
the production of the polypeptide that the DNA coded for.