This exam is worth 50 pts.
Exam I, Fall 2010
Evolutionary Biology
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Multiple Choice Questions. Choose the best possible answer. Use the bubble sheet. 1 pt. each
1. A medical scientist is designing an experiment to test the results of a new drug that she hypothesizes will
greatly reduce and possibly eliminate the side effects of a new cancer treatment. If this experiment is to be set
up correctly, she must
(A) divide the patients into two groups and give each group the same amount of the new drug.
(B) divide the patients into two groups and give one group the new drug and give the other group nothing.
(C) divide the patients into two groups and give one group the new drug and the other group a drug that has no
effect (for example, a tablet that only contains sugar).
(D) divide the patients into two groups and give one group the new drug for one week and the other group a
different drug for one week.
(E) divide the patients into two groups and give one group one-half of the dosage of the new drug and the other
group nothing.
2. As part of your research project, you travel to an island to learn more about the habitats and relationships of
spiders, centipedes and insects. You and your assistant plotted out five different areas of the island and counted
the numbers of spiders, centipedes, and insects living in each plot. Here are your results:
Plot
1
2
3
4
5
Spiders
300
426
147
739
79
Insects
25
17
15
78
13
Centipedes
4
10
21
0
93
The best explanation for the high number of spiders in plot 4 is
(A) there are too many insects.( B) there are no centipedes to eat the spiders and there are abundant insects
upon which to feed. (C) the spiders ate the centipedes and ignored the insects (D) the insects ate the centipedes
and avoided the spiders.
3. The plots that were staked out on the island were part of the (A) question.(B) observation.(C) hypothesis.
(D) experimental design. (E) conclusion.
4. One testable hypothesis that the investigators could examine is that (A) herbivorous insects prefer islands
where spiders and centipedes live. (B) herbivorous insects are not particular about where they live.
(C) the number of centipedes feeding on them influences herbivorous insects and spider numbers.
(D) spiders are effective at avoiding herbivorous insects. (E) All are equally testable hypotheses.
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5. According to radiometric dating, the (A) solar system is about 6,000 to 10,000 years old. (B) the earth is
about 4.5 years old and the solar system is 13 billion years old (C) the oldest fossils on earth are 4.6 billion
years old and the universe is 13 billion years old (D) the earth is 4.6 billion years old and the oldest fossils are
3.5 billion years old. (E) the solar system is 4.6 billion years old and the oldest fossil is 2.2 billion years old.
6. The scientific method involves making careful observations, asking questions, formulating hypotheses,
collecting data, testing, and making conclusions about the collected data. Of the following statements about
toxic wastes, select the choice that science cannot address. (A) Science can test for the presence of toxin in a
river. (B) Science can determine the level of toxin that is lethal to fish in the river. (C) Science can say that a
river should not be polluted. (D) Science can formulate hypotheses about how a river was polluted.
(E) Science can determine the rate of mutations caused by toxins in a river.
7. Evolutionary change will not take place in a population: (A) unless there is some form of natural selection.
(B) if there is a lit of genetic variability within the population. (C) in the absence of high mutation rates (D) if
all alleles are equal in their selective value. (E) if allele frequencies remain constant from one generation to the
next.
8. Evidence for evolution can be obtained by examining presently existing species through studies on each of
the following except one. Select the exception. (A) early development (B) vestigial structures (C) patterns of
distribution (D) convergence (E) analogous structures
9. The molecular record suggests that a series of evolutionary changes is tied to a progressive accumulation of
(A) extinctions. (B) alterations of DNA sequences. (C) modifications of the environment. (D) somatic
mutations. (E) structural modifications.
10. Which of the reasons does not explain why "scientific creationism" cannot be considered a science?
(A) It is not supported by any empirical observations. (B). It does not obtain its principles from observation, as
does science. (C) Its assumptions lead to no hypotheses that could be tested and possibly disproved. (D) The
idea of creation by a supernatural agency lies outside the realm of science. (E) Only non-scientists believe it.
11. The observation that different geographical areas sometimes exhibit plant and animal communities of
similar appearance, even though the individual plants and animals are not closely related, is called
(A) the fossil record. (B) homology. (C) convergent evolution. (D) divergent evolution. (E) adaptation.
12. The "scientific creationism" view includes all of the following beliefs except (A) biblical account of the
origin of the earth is literally true. (B) the earth is much younger than most scientists believe. (C) all species of
organisms were individually created. (D) the organisms did not change from their original appearance.
(E) extinct species are replaced with new ones.
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13. A friend is trying to understand the concept of convergent evolution. Which one of the following statements
best describes this concept? (A) Convergent evolution occurs when two species living in the same area become
reproductively isolated. (B) Convergent evolution occurs when two species living in different areas become
reestablished and are able to reproduce. (C) Convergent evolution occurs when two species living in the same
area are competing for the same resource thus causing one to evolve away from the other. (D) Convergent
evolution occurs when two species living in different areas evolve similarities through natural selection acting
on those characteristics.
14. In comparing artificial and natural selection, which of the following statements is true?
(A) Artificial selection is slower than natural selection. (B) Artificial selection is reversible; natural selection is
not. (C) Artificial selection can produce maladaptive structures, natural selection cannot.
(D) Artificial selection cannot produce changes as large as changes produced by natural selection.
(E) In artificial selection, the magnitude of the selection pressure can be varied; in natural selection, it cannot.
15. A rock contains 18 mg of the radioactive isotope carbon-14. The half-life of carbon-14 is 5,600 years. How
many half-lives and years will it take before the carbon-14 decays to less than 4 mg? (A) 1 half-lives; 5,600
years (B) 2 half-lives; 11,200 years (C) 3 half-lives; 16,800 years (D) 4 half-lives; 22,400 years (E) 9 half-lives;
50,400 years
16. Which one of the following statements about the evolutionary divergence of horses in North America is
false? (A) Most changes are seen as adaptations for life in grassland habitats. (B) The general trends during
horse evolution are increase in body size, lengthening of limbs, reduction of digits on both sets of limbs, and
tooth development for a grazing life style. (C) Global climate change during the Miocene and early Oligocene
epochs caused many of the changes in the evolution of horses. (D) Horse evolution is unusual in that rates of
change were uniform and constant throughout most lineages. (E) Living lineages of horses show much less
diversity than existed in the past.
17. Which one of the following is not important to the concept of homology? (A) Homologous features must be
found in a common ancestor. (B) It can include anatomical, physiological, or molecular features. (C) Features
must share a common developmental pattern. (D) Species with homologous features must be related. (E) None
of the features being compared can be vestigial.
18. Down syndrome is a genetic condition resulting from (A) aneuploidy (B) gene mutation (C) polyploidy
(D) crossover (E) none of the above.
19. Let P = purple flowers and p = white, and T = tall plants and t = dwarf. What combinations of gametes
could be produced by a heterozygote for both the traits? (A) PpTt only. (B) Pp, Tt. (C) P, p, T, t. (D) PT, Pt,
pT, pt. (E) infertile, no gametes produced.
20. Let P = purple flowers and p = white, and T = tall plants and t = dwarf. Of the 16 possible gamete
combinations in the dihybrid cross, how many would be the phenotype white, tall? (A) none (B) 1
(C) 3 (D) 9 (E) 16.
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21. When Mendel crossed two purple-flowered pea plants with each other, he obtained a phenotypic ratio of 3:1
(purple-flowered pea plants to white-flowered pea plants). His results are consistent with which of the following
sets of parents? (A) homozygous dominant purple pea plant and homozygous recessive white pea plant
(B) homozygous dominant purple pea plant and heterozygous white pea plant (C) heterozygous purple pea plant
and homozygous recessive white pea plant (D) heterozygous purple pea plant and homozygous dominant purple
pea plant (E) heterozygous purple pea plant and heterozygous purple pea plant.
22. Height and intelligence are two examples of continuous variation in humans. Whereas in pea plants the tall
allele is dominant over the short allele, there are no intermediate heights in peas. Which of the following is the
best explanation for the differences described above? (A) Humans are more advanced than pea plants; thus, the
genetics of peas is much simpler than humans. (B) The intermediate size pea plant seeds are aborted within the
seedpod and thus will never develop. (C) The intermediate size pea plant seeds have deleterious alleles that
prevent them from germinating. (D) Many genes, rather than one gene for a characteristic, control some
variations in species. (E) These variations in humans are affected by lack of dominance in the alleles that
control these traits.
23. Children born in areas where proper nutrition is not available to them do not always realize their full growth
potential. These children have the genes for normal growth of bones. Which of the following statements can
best explain this situation? (A) There is a lack of dominance in the alleles for normal bone growth; as a result,
the genotype is directly affected. (B) Since nutrition is necessary for proper development and is a part of the
environment, it is a clear case of environmental effect on the phenotype. (C) Since nutrition is necessary for
proper development and is a part of the environment, it is a clear case of environmental effect on the genotype.
(D) There will always be examples that reflect this condition in human populations because of the continuous
variation that exists for this characteristic. (E) The children's parents did not obtain the proper nutrients when
they were young and thus were not able to pass on the alleles for normal growth and development.
24. Irene and William are having their first child. Irene knows her blood type is A, but William does not know
his blood type. However, William knows that his mother and father were B. Their first child is a boy named
Gregory. Gregory has type O blood. Of course, Irene and William do not understand how this happened. You
could explain this to them using which of the following choices?
A. Irene's genotype is AA, and William's genotype is OO; thus, Gregory expresses the phenotype of O.
B. Irene's genotype is AO, and William's genotype is BO; thus, Gregory expresses the phenotype of O.
C. Because his parents were both type B, William could not be the father of Gregory.
D. Gregory's blood type will need to be checked after his first month of life if the parents want to know his
blood type. It takes about a month for the blood type to develop in a newborn child.
E. Since Irene is type A, there had to be a mix-up in the lab report. Gregory should have been type A.
25. How many different types of gametes can be formed by plants with a genotype of PpYYrrTt?
(A) one (B) 2 (C) 4 (D) 8 (E)16
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26. In white tigers, the absence of fur pigmentation is caused by a recessive allele. This allele also causes the
tigers to be cross-eyed. If two tigers heterozygous for this allele mate and produce offspring, what percentage
can be expected to be white and/or cross-eyed? (A) 25% will be white and the same 25% will be cross-eyed.
(B) 25% will be white and 25% will be cross-eyed, but not necessarily the same 25% due to independent
assortment. (C) 50% will be both white and cross-eyed. (D) Because it is a recessive allele, none of the
offspring in the F1 generation will be white or cross-eyed.
27. Let Y = yellow and y = green, and R = round and r = wrinkled. You cross YYRR peas with yyrr peas. All of
the F1 individuals are yellow and round with a genotype of YyRr. You then perform a F2 cross and get the
expected 9:3:3:1 phenotypic ratio. Which of the following is the correct genotypic ratio for yellow, round F2
individuals? (A) 1/16 YYRr, 2/16 YYRR, 2/16 YyRR, 4/16 YyRr
(B) 1/16 YyRr, 2/16 YYRr, 2/16 YyRR, 4/16 YYRR (C) 1/16 YYRR, 1/16 YYRr, 1/16 YyRR
(D) 1/16 YYRR, 2/16 YYRr, 2/16 YyRR, 4/16 YyRr
28. In humans, the male has an X and Y sex chromosome. The human female has two X chromosomes. In birds,
the female has a Z and a W sex chromosome while the male has two Z chromosomes. Which of the following
statements is accurate about which parent controls the gender of the offspring? (A) In humans and birds the
male controls the gender of all the offspring. (B) In humans and birds the female controls the gender of all the
offspring. (C) In humans the male controls the gender of the offspring, and in birds the female controls the
gender. (D) In humans the female controls the gender of the offspring, and in birds the male controls the gender.
(E) Control of the gender of any human or bird offspring is related to the environmental conditions at the time
of conception.
29. You are a herpetologist studying snapping turtles. You house the turtles in an incubator set at 22ºC. After a
period of time you find that some new baby turtles have hatched. Interestingly, all of the baby turtles are
male. Based on this observation (A) you conclude that sex-determination is temperature dependent. (B) you
hypothesize that only male turtles survive at room temperature. (C) you hypothesize that sex-determination in
turtles in influenced by temperature, but you need more data to be sure. (D) you realize that it was a coincidence
that only males were born since gender is always determined by sex chromosomes.
30. Consider the following sequence:
5'AUGGCUACAGAUAGCUGGGGCUGAAAAAAAAAAAAAAAA3' Translated, the corresponding protein
contains how many amino acids? (A) one (B) 6 (C) 7 (D) 8 (E) 13B.
31. Given the sentence "THE FAT CAT ATE THE RED RAT," which of the following would represent a
frameshift mutation? (A) THE FAT CAT ATE THE RED RAT (B) THE CAT ATE THE RED RAT
(C) THE FAC ATA TET HER EDR AT (D) THE FAT RAT ATE THE RED RAT
32. If a cell has 32 chromosomes and undergoes mitosis followed by cell division, each new daughter cell will
have how many chromosomes? (A) 64 (B) 32 (C) 16 (D) 8 (E) 4
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33. A biologist is examining reproductive cells at the end of meiosis I. She notices that each of the two resulting
cells are haploid. She also knows that meiosis II will produce haploid cells. How can her observations be
explained? (A) There must be an error and she needs to refocus her microscope and look again. (B) The cells
that resulted from meiosis I are in fact haploid, but are composed of two sister chromatids. The sister
chromatids will be pulled apart during meiosis II, producing haploid gametes. (C) The cells that resulted from
meiosis I are in fact diploid and this explains her observational error and also her knowledge of the meiosis II
resulting in haploid cells. (D) The cells that resulted from meiosis I are in fact haploid, but her knowledge of the
result of meiosis II is not accurate, at least for this particular cell type. (E) The cells that she observed are
abnormal and will require further observations.
34. Meiosis also has been called reduction division because (A) new somatic cells are produced but with a
reduction in the required amount of time, which promotes faster wound healing. (B) new gametes are produced
but their numbers are reduced. (C) there is a reduction in the chromosome number during two separate nuclear
and cell divisions to produce gametes. (D) there is a reduction in the chromosome number during two separate
nuclear and cell divisions to produce somatic cells.
E. there is an initial reduction in the chromosome number during the first division followed by an increase in
chromosome number, the second division quickly follows the increase in number of chromosomes.
35. Consider the following representation of four chromatids during undergoing meiosis I shown below. The
paternal chromosome is in upper case, while the maternal chromosome is in lower case.
ABCDEFG
ABCDEFG
abcdefg
abcdefg
If there was a single crossing over event between the second and third chromosomes from the top, the resulting
chromosomes (in order) would be
A. A B C D E F G; A B C D E F G; a b c d e f g; a b c d e f g.
B. A B C D E F G; A B c d e f g; A B C D E F G; A B c d e f g.
C. A B C D E F G; A B c d e f g; a b C D E F G; a b c d e f g.
D. A B C D E F G; A B c d e F G; a b C D E f g; a b c d e f g.
36. Which of the following statements regarding reduction division is false? (A) Paired homologous
chromosomes segregate to different nuclei thus reducing the chromosome number by one half.
(B ) eduction division occurs refers to both meiosis I and II. (C) It occurs with an absence of centromere
division. (D) The daughter nuclei each have one-half as many centromeres as the parental nucleus.
37. Most viruses form a capsid around their nucleic acid core. This capsid is composed of a(n)
(A) protein. (B) monosaccharide. (C) antigen. (D.) glycoprotein. (E) lipoprotein.
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38. Which of the following is a unique feature of viruses that separates them from bacteria?
(A) They are generally smaller. (B) They are often highly toxic. (C) They lack proteins. (D) They have
different nucleotides in their hereditary material. (E) They cannot exist outside of a host cell.
39. If we had the opportunity to analyze the DNA of Archaeopteryx, which of the following animals’ DNA
would likely be most similar? (A) bat (B) ostrich (C) frog (D) flying fish (E) snake.
40. Archaeopteryx only appears to be found in a certain area of Europe around Bavaria. Which term would
biogeographers use for this type of distribution? (A) Disjunct (B) Endemic (C) Cosmopolitan (D) Continuous
(E) None of the above.
41. Suppose you were to find an organism with cells having ribosomes, endoplasmic reticulum, cell wall, DNA,
and it lacked chlorophyll, which taxonomic group would you most likely be holding? (A) Archea (B) Bacteria
(C) Animalia (D) Fungi (E) Plantae
42. If in rhinos the horn length phenotype were produced by the accumulative effect of four genes from different
loci, this would be an example of….(A) polygene inheritance (B) partial dominance (C) conditional gene
expression (D) multiple alleles (E) codominance
43. What is the best example of the phrase “ontogeny recapitulates phylogeny”? (A) the parallel evolution of the
wing pattern of two closely related butterfly species (B) the homeobox expression in Drosophila (C) the
development of the blowhole of whales (D) the progressive size increase seen during horse evolution (E) the
formation of petrified wood during the process of permineralization.
44. The greatest value of plate tectonics to the field of evolution is to (A) indicate the true age of the earth.
(B)explain how barriers such as the Himalayan Mountains are formed. (C) explain the volcanic origin of the
Galapagos Islands (D) explain the distribution of many organisms (E) show how continental drift promotes
evolution.
45. “A substitution point mutation is less likely to cause a serious disruption in cell function than an addition
mutation.” What is the reasoning behind this statement? (A) A substitution will change only one amino acid but
an addition will lead to multiple amino acid changes (B) A substitution will not produce a stop codon and an
addition will. (C) A substitution will not lead to a silent mutation but an addition will likely do so. (D) A
substitution may lead to a new start codon while an addition will usually not do so. (E) None of the above.
46. Assume R (round) is dominant to r (smooth) and T (tall) is dominant to t(short). Suppose an individual who
is homozygous for both traits breeds with an individual who is heterozygous for both traits. What would be the
difference in the results if there were independent assortment compared to the situation where RT was linked and
rt were linked? (A) If independent, there would be four types of gametes; if linked, there would be only three.
(B) If independent, there would be four types of genotypes; if linked, there would be three. (C) If independent,
there would be one type of phenotype and the same would be true if they were linked. (D) If independent, there
would be one type of phenotype; if linked, there would be four types of genotypes. (E) None of the above.
47. The increase of DNA copies prior to reproduction of the cell is called: (A) DNA transduction (B) DNA
transversion (C) DNA transcription (D) DNA translation (E) none of the above.
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48. In comparing the two diagrams below, which organism is the most closely related to whales and
porpoises? (A) perissodactyls in diagram A and hippopotamids in diagram B. (B) mesonychians in
diagram A and hippopotamids in diagram B. (C) mesonychains in diagram A and ruminants in diagram
B. (D) None of the above. (E) You cannot determine degree of relatedness from these diagrams.
49. From the diagrams below, the immediate ancestor of all of the species is a (A) hippopotamid
(B) mesonychain (C) cetacean (D) none of the above (E) You cannot determine relatedness from these
diagrams.
50. According to diagram B, the ancestor of the “Artiodactyla” belongs to the (A) camel family (B) is a
horse-like animal (C) a pig-like animal (D) is a hippopotamid (E) none of the above.
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