This exam is worth 50 pts. Evolutionary Biology . . Exam I, Fall 2010
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 / Spiders / Insects / Centipedes1 / 300 / 25 / 4
2 / 426 / 17 / 10
3 / 147 / 15 / 21
4 / 739 / 78 / 0
5 / 79 / 13 / 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.
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.
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.
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
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
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.
A B C D E F G
A B C D E F G
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.