Download Part 1 - Evolutionary Biology

This exam is worth 100 points
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Evolutionary Biology
Exam II Part I
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A. Multiple Choice Questions. Choose the best possible answer. Use the bubble sheet
1. Humans and chimpanzees diverged about 6 million years ago. If 12 nucleotide substitutions have occurred between
human and chimpanzee lineages in a sequence of mitochondrial DNA, and 48 have occurred between humans and rhesus
monkeys, then humans and rhesus monkeys, according to the molecular clock hypothesis, separated _______ million
years ago. A) 6 B) 12 C) 24 D) 48 E) None of the above
2. Suppose a population of flour beetles has 1,000 individuals. Normally the beetles are red; however, this population is
polymorphic for a mutant autosomal body color, black, designated by bb. Red is dominant to black, so BB and Bb
genotypes are red. Assume the population is at Hardy–Weinberg equilibrium, with equal frequencies of the two alleles.
What would be the allele frequencies if a population bottleneck occurred and only four individuals survived: one female
red heterozygote and three black males?
A) 0.125 red; 0.875 black B)0.875 red; 0.125 black C) 0.25 red; 0.75
black D) 0.75 red; 0.25 black E) 0.5 red; 0.5 black
3. What would be the expected frequencies of the red and black phenotypes in the original population of beetles? A) 0.5
red; 0.5 black B) 0.75 red; 0.25 black C) 0.25 red; 0.75 black D) All red E) Insufficient information is given to answer
the question.
4. Given the original population data and a Hardy-Weinberg equilibrium, what are the frequencies of the homozygous
dominant, heterozygous, and homozygous recessive (in that order) after 100 generations, assuming that no selection or
other evolutionary processes are operating?
A) 0.25; 0.5; 0.25
B) 0.75; 0.20; 0.05 C) 0; 0.5; 0.5
D.) 0; 0; 1
E) None of the above
5) Sperm compete to fertilize an egg. What type of competition is this? A) interspecific B) intraspecific C) female choice
D) threat display E) Mullerian
6. Which of the following statements concerning genetic information in most cells is true? A) The entire DNA molecule
is copied to RNA during DNA replication. B) A single DNA nucleotide codes for a single amino acid. C) The flow of
information in a cell is from DNA to RNA to protein. D) The flow of information in a cell is from protein to RNA to
DNA. E) The flow of information in a cell is from DNA to protein to RNA.
7. Which of the following mutations would be considered the most significant in terms of evolution? A) an individual
experiences a point mutation in its intestinal cells B) a population experiences inversion of 3 chunks of DNA in the bone
cells C) an individual experiences a nucleotide addition in its gametic cells D) an individual experiences a nucleotide
subtraction in its somatic cells E) an individual experiences a nucleotide substitution in its brain cells
8. Humans and African apes (chimpanzees, bonobos, and gorillas) share traits, such as elongated skulls and shortened
canine teeth, which other related species do not have. These shared characteristics are called A) homoplasies. B)
synapomorphies. C) cladistics. D) parsimonies. E) heteroplasies.
9. In cocker spaniels, black color (B) is dominant over red (b), and solid color (S) is dominant over spotted (s). Suppose
the genes are unlinked and the offspring of BBss and bbss individuals are mated with each other, and their offspring in
turn are mated. What fraction of the latter’s offspring will be black and spotted? A) 1/16 B) 9/16 C.) 1/9 D) 3/16
E) 3/4
10. Which of the following statements is true? A) DNA is partially replicated but completely transcribed. B) DNA is
completely replicated but only partially transcribed. C) RNA is completely replicated but only partially translated. D)
DNA is completely replicated and completely translated. E) DNA is partially replicated but completely translated.
11. Fireflies are able to distinguish between their own species and other species by the rate and brightness of their flashing
patterns and they choose only to mate with their own species. What reproductive isolating mechanism is in operation?
This is an example of A) seasonal isolation B) mechanical isolation C) ecological isolation D) geographic isolation E)
behavioral isolation
12. A group that includes the common ancestor and all of its descendants is considered to be A) paraphyletic. B)
polyphyletic. C) synapomorphous. D) monogamous. E) monophyletic.
13. A new planet is forming and scientists monitor it to see if life develops. After several years of winds, heat, and
atmospheric turmoil, a scientist at UB discovers small peptides and nucleotides in the water on the planet. Which theory
best explains what might be going on? A) Panspermia because we are talking about a planet different than Earth. B)
Primary abiogenesis because this seems like the Miller and Urey experiments. C) Spontaneous generation because these
organic molecules seemed to develop seemingly from nowhere. D) Devine Creation E) Degeneracy Hypothesis
14. Which tissue in a human is analogous to the antheridium in moss? A) ovary/uterus B) digestive tract C) liver D) testes
E) pancreas
15. Suppose that a pharmacologist discovers a chemical she thinks might have antibiotic properties. She decides to test
this by exposing 100 colonies of E. coli bacteria to the chemical and finds that 5 colonies survive. How were these
colonies able to survive when the other colonies weren’t? A) by chance they had a physiology that could resist the
chemical B) during the course of the experiment they evolved the capacity to resist the chemical C) they learned to resist
the chemical D) they developed mutations that were targeted toward attacking the chemical E) they had horizontal transfer
of alleles from resistant bacteria.
16. There are two species of macaws that occupy the same forest in the Amazon. Their Linnean Nomenclature suggests
that they are different species; one is Ara macao and the other is Anodorhynchus hyacinthinus. Field researchers find
however, that though the two are different is many respects they still try to mate with each other. What would you
conclude about these macaws? A) They are actually the same species B) They are actually the same species because their
names say so. C) They are creating a situation of runaway selection. D) The male competition keeps the scarlet macaws
from mating with the hyacinth macaws. E) Nothing. The scientist would have to wait and see if viable offspring are
produced.
17. In what part of the human cell does the breakdown of glucose to pyruvic acid occur? A) nucleus B) Cytoplasm C)
mitochondrion D) Golgi apparatus E) none of the above
18. Consider the following double-stranded DNA region:
5’-TTCCAT-3’
3’-AAGGTA-5’
If the upper strand is transcribed, which of the following strands will result? A) AAGGTA
CODON D) UUGGTA E) AAGGUA
B) TTCCAT C) STOP
19. Males of a species of a lizard that lives on an island are red and the females are brown. Recently, introduced rats have
been noted to eat the males that are brightest in color. After many generations the male lizards all look brown. This is an
example of A) disruptive selection B) exaptation C) sexual selection D) divergent evolution E) natural selection
20. Suppose Mendel had an assistant who sometimes forgot to remove the anthers of the short plants before placing
pollen from the homozygous tall plants on the pistils of the short plant flowers. As a result, about 2/3 of the pollen that
fertilized the short flowers came from short plants. What fraction of the progeny from this cross would have been tall?
(Recall that the trait of tall is dominant to short.) A) 1/3 B) 1/2 C) 2/3 D) 3/4 E) All of them
21. Which of the following traits would be least useful in a phylogenetic analysis? A) A trait that is altered easily by
small changes in temperature B) A trait that involves genetically inherited behaviors C.) A trait that is detectible only
in observations of early development D.) A trait that can be studied only in museum specimens E) All of the above
traits would be equally useful in a phylogenetic analysis.
22. Mullerian mimicry is also a form of…. A) mutualism B) ammensalism C) Competition D) Parasitism E)
commensalism
23. Tay-Sachs disease is an autosomal recessive disorder that destroys nerve cells in the brain and spinal cord. What is
the probable reason that the recessive allele is not eliminated from the population? A) The recessive allele will in fact be
rapidly eliminated because it has no benefit B) The disease is not that harmful to the individual so the recessive allele will
stay in the population C) There is a high mutation rate of the normal allele to the Tay-Sachs condition. D) There may be a
benefit for the heterozygous condition such as protection against tuberculous. E) All of the above
24. In Netherlands dwarf rabbits, a gene showing incomplete dominance produces three phenotypes. Rabbits that are
homozygous for one allele are small; individuals that are homozygous for the other allele are deformed and die;
individuals that are heterozygous are dwarf. If two dwarf rabbits are mated, what proportion of their surviving offspring is
likely to be dwarf? A ) 1/4 B) 1/3 C) 1/2 D) 2/3 E) 3/4
25. What happens to pyruvic acid that is produced in anaerobic bacteria A) forms alcohol B) is excreted C) is converted
to lactic acid D) forms acetic acid E) any of the above can occur
26. Mikayla has germ cells. What does that mean? A) Some of her cells are infected with a virus B) Some of her cells are
infected with bacteria C) Some of her cells can pass on genetic information to offspring D) Some of her cells that pass on
genetic information to offspring are infected with a virus E) Some of her cells are carrying epigenetic tags.
27. Assume you have just discovered a new antibiotic. Suppose in lab you expose 10,000 colonies of the bacterium E.
coli to the new chemical and only 5 survive. How were the five E. coli colonies able to survive when all others failed? A)
By chance they had natural immunity to the “antibiotic.” B) They evolved to be able to resist the “antibiotic” C) They
were able to destroy the attacking “antibiotic.” D) They learned to resist the “antibiotic.” E) The need to survive was
obviously present.
28. Based on their chlorophyll, which organism is the best candidate to be the Protist ancestor of land plants? A) blue
green bacteria B) green bacteria C) green algae D) mosses E) liverworts
29. Octopus and fish both have similar eye structures due to A) Divergent evolution B) Convergent evolution C)
Evolutionary reversal D) Allopatric speciation E) Sympatric speciation
30. What is the proportion of alleles most likely to be shared by a brother and sister? A) all B) 3/4 C) 1/2 D) 1/4 E) 1/8.
31. Mutations A) are never passed on to offspring B) must occur in the gonads in order to be passed on to offspring C)
must occur in somatic cells to order to be passed on to offspring D) are limited to somatic cells E) B and C
32. Which of the following was required for sympatric speciation in species like the apple maggot fly? A. Genetic drift
B. Stabilizing selection C. Disruptive selection D. Allopatry E. Polyploidy
33. The biological species definition is not applicable to A) plants B) parasites C) asexual organisms D) sympatric
species E) endemic populations
34. A parent cell divides to form two genetically identical daughter cells in the process of mitosis. For mitosis to take
place: (A) the parent cell must first be fertilized (B) the parent cell must replicate its entire genome prior to mitosis
(C) the parent cell must reproduce its DNA during telophase (D) the parent cell must divide its DNA in half so each
daughter cell gets only the genes needed to carry out its functions. E) The parent cell must replicate its DNA twice in
order that the daughter cells will have a full complement of chromosomes.
35. In a population of tree swallows, 18 individuals are homozygous for the c4 allele, 22 individuals are heterozygous for
the allele, and 10 individuals lack the allele. What is the frequency of the c4 allele
A) 0.29 B) 0.36 C) 0.40 D)
0.58 E) 0.80
36. The half-life of carbon-14 is 5,700 years. If 5% of the original carbon-14 is left in a structure, that structure is
_______ years old. A ) less than 2,850 B) about 5,700 C) between 11,400 and 17,100 D) between 17,100 and
22,800 E) about 25,000
37. Chromatin is a series of entangled threads composed of
proteins. D) cytoskeleton. E) membanes.
A) microtubules. B) DNA and protein.
C) fibrous
38. In a certain population of snails we discover that disruptive selection is occurring. In this population, which
organisms are most likely to survive? A) those with average traits B) those with extreme traits C) those that are sexually
selective D) those that are small E) those with a high mutation rate.
39. The “RNA world” hypothesis is supported by evidence that A) RNA molecules spontaneously form spheres in
water. B) RNA can act as both genetic material and a catalyst. C) amino acids can form RNA in particular chemical
environments. D) RNA can act as genetic material but not as a catalyst. E) RNA monomers can form proteins.
40. A dog has 78 chromosomes. After Meiosis II is completed, how many chromosomes will each daughter cell have and
how many total daughter cells will be created? A) 2 daughter cells with 78 chromosomes each. B) 4 daughter cells with
78 chromosomes each. C) 2 daughter cells with 39 chromosomes each. (D) 4 daughter chromosomes with 39 cells each.
E) none of the above.
41. The Kuna Indian population on islands off Panama have a high proportion of albinos. These moon children as they are
called are highly prized as mates hence the alleles for albinism are more frequent in the tribe then might be expected. This
is an example of A) artificial selection B) natural selection C) genetic drift D) flounder effect E) sexual selection
42.Connor’s father is color blind and his mother is not. We know that his mother is not a carrier for color blindness. What
is the probability that Connor is color blind? A) 0% but he is a carrier B) 0% but he is not a carrier C) 25% but he is not a
carrier D) 50 % and he is a carrier E) None of the above.
43. Down Syndrome is an example of what kind of mutation? A) polyploidy B) aneuploidy C) addition D) substitution E)
translocation
44. Which is the best way to estimate the length of time that two species have been separated evolutionarily? A) compare
pieces of DNA coding for a structural protein that is present in both species B) studying the many nucleotide sites in both
species and taking an average differences between DNA and RNA C) comparing pieces of DNA for a functional enzyme
that is present in both species D) comparing the DNA differences between two species in non-coding regions E)
Comparing fitness levels
45. What is the function of the nucleolus? A) synthesizes ribosomes B) produces protein C) generates ATP D) forms
spindle fibers for chromosome movement E) none of the above
46.Co-dominance could be considered as supporting evidence for A) Fleming Jenkins blending hypothesis argument B)
Mendel’s particulate theory C) Darwin’s theory of Natural Selection D) Cuvier’s catastrophe hypothesis E) None of the
above.
47. According to the endosymbiotic theory, why was it adaptive for the larger (host) cell to keep the engulfed cell alive,
rather than digesting it as food? (A) The engulfed cell provided the host cell with ATP. (B) The engulfed cell provided the
host cell with carbon dioxide. (C) The engulfed cell allowed the host cell to metabolize glucose. (D) The host cell was
able to survive anaerobic conditions with the engulfed cell alive. (E) The host cell would have been poisoned if it had
digested the engulfed cell.
48. Chloroplasts are believed to have evolved by A) an eukaryotic cell forming a mutualistic relationship with
cyanobacteria B) horizontal gene transfer of chlorophyll genes from a green alga C) two prokaryotic cells forming a
symbiotic relationship D) infolding of the endoplasmic reticulum to form grana E) evolution of chlorophyll within a
eukaryotic cell
49. You discovered 3 different species of insects with very similar color patterns. What evidence would you consider
relevant to determine if they are displaying Mullerian or Batesian mimicry? A) test the DNA of the 3 species, then
compare them against the most recent ancestor(s). B) evaluate if all 3 species display traits that are harmful or undesirable
to their predators C) classify the patterns and colors based on Mullerian and/or Batesian index and calculate the ratio
between the two D) Observe if their interaction with the environment was harmful E) none of the above
50. Again: this is an experiment being run by one of the lecture TA’s. We are not interested in your personal data, but the
total combined class data. You will get credit for any answer you choose.
So far in this semester, how often have you used your cell phone for non-course related activities during class for BIO
200? Please be honest. All answers will be counted as correct. A) Never B) about 5% per class C) about 10% per class
D) about 20% per class E) more than 20% per class
5.