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Unformatted text preview: Your Name: ANSWER 1 Midterm 1, BISC120L, Fall 2008 A. Multiple Choice (2 pts x 15 = 30 pts). Select the most appropriate answer and write in CAPITAL LETTERS ONLY in the accompanying box. 1. In a cross AaBbCc x AaBbCc , what is the probability of producing the genotype AABBCC? A. 1/4 B. 1/8 C. 1/16 D. 1/32 E. 1/64 2. Black fur in mice ( B ) is dominant to brown fur ( b ). Short tails ( T ) are dominant to long tails ( t) . What fraction of the progeny of the cross BbTt x BBtt will have black fur and long tails? A. 1/16 B. 3/16 C. 3/8 D. 1/2 E. 9/16 3. In humans, males are more often affected by sex-linked traits because A. males have only one copy of the X chromosome. B. male hormones such as testosterone often alter the effects of mutations on the X chromosome. C. female hormones such as estrogen often compensate for the effects of mutations on the X. D. X chromosomes in males often have more mutations than X chromosomes in females. E. mutations on the Y chromosome often worsen the effects of X-linked mutation. 4. Natural selection is based on all of the following except A. genetic variation exists within populations. B. the best adapted individuals tend to leave the most offspring. C. individuals who survive longer tend to leave more offspring than those who die young. D. populations tend to produce more offspring than the environment can support. E D A E Your Name: ANSWER 2 E. individuals adapt to their environments and, thereby, evolve. 5. Which of the following statements about Darwin's finches is false? A. They are a classic example of an adaptive radiation. B. They were critical to the development of Darwin's theory of natural selection. C. They are believed to descend from a single, mainland species. D. Their beaks have been selected to become deeper during dry years. E. They include a species of 'vampire finch' that feeds on blood. 6. Which of the following indicates a population is not in Hardy-Weinberg equilibrium? A. p + q 1. B. p 2 + 2 pq + q 2 1. C. The allele frequencies are not 50:50. D. The observed allele numbers match the expected allele numbers. E. The observed genotype numbers do not match the expected genotype numbers. 7. In a certain group of African people, 9% are born with sickle-cell disease (homozygous recessive). If this group is in Hardy-Weinberg equilibrium, what percentage of the group has the selective advantage of being more resistant to malaria (heterozygous) than those individuals who are homozygous for normal hemoglobin or for sickle-cell disease? A. 18% B. 21% C. 30% D. 42% E. 81% 8. A population has the following genotypes: 10AA, 2BB, 5CC, 12AB, 9AC, 12BC. What is the frequency of the A allele?...
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This note was uploaded on 12/01/2010 for the course BIO 120 taught by Professor Staff during the Spring '07 term at USC.
- Spring '07