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Unformatted text preview: cus (Y) having two alleles (Y, y): yellow (yy) and green (YY, Yy). The fitness of the morphs is frequency-dependent, as indicated in the graph above. If the frequency of the yellow morph in a population is 0.70 and individuals are randomly mating, then the expected equilibrium population due to natural selection is (A) monomorphic for yellow morphs (B) monomorphic for green morphs (C) polymorphic with a stable ratio of about 1:1 of yellow to green morphs (D) polymorphic with oscillating frequencies of yellow and green morphs (E) polymorphic, but always with a higher frequency of yellow morphs than green morphs 116. The fitness of a genotype is higher when it is rare in a population than when it is common. Which of the following types of selection is most likely operating? (A) (B) (C) (D) (E) Density-independent selection Frequency-dependent selection Directional selection Stabilizing selection Disruptive selection 112. When exposed to a cold environment for several weeks, many small mammals dramatically increase their capacity for heat production primarily by means of (A) (B) (C) (D) (E) decreased insulation increased insulation increased renal function shivering thermogenesis nonshivering thermogenesis 113. Plant species A has a diploid number of 12, while species B has a diploid number of 16. Which of the following would be the diploid number of an allotetraploid derived from a hybrid between these two species? (A) (B) (C) (D) (E) 14 28 40 44 56 114. If two parents that are heterozygous (Aa) at a single locus give rise to offspring that are 25 percent AA, 50 percent Aa, and 25 percent aa, then all of the following are true EXCEPT: (A) (B) (C) (D) (E) The parents are diploid organisms. The a allele is recessive lethal. The alleles assort independently. The gametes combine at random. The probability that a given gamete will receive allele A is one-half. GO ON TO THE NEXT PAGE. Unauthorized copying or reuse of any part of this page is illegal. 37 117. The mating system in which a female defends a large, multipurpose territory within which several males defend smaller, exclusive territories is known as (A) (B) (C) (D) (E) polygynandry resource defense polygyny resource defense polyandry resource defense promiscuity harem defense polygyny 120. When numbers of organisms and amounts of living material in successively higher trophic levels are compared, the values usually take the form of a pyramid, with the largest numbers and greatest biomass in the producer trophic level. However, in some marine ecosystems, the consumer trophic levels contain significantly greater amounts of living material than does the primary-producer trophic level. The best explanation for this is which of the following? (A) The main primary producers in marine ecosystems are microscopic algae with extremely high rates of population turnover. (B) Most consumers in marine ecosystems are filter feeders that must maintain large basketlike structures for extracting food from the water. (C) The increased availability of solar radiation in marine ecosystems means that fewer primar...
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This document was uploaded on 03/16/2014 for the course BIO 1434 at UT Arlington.
- Spring '14