31. The processes of ____ and ____ generate variation, and____ produces adaptation to the environment.
(a) sexual recombination . . . natural selection . . . mutation
(b) mutation . . . sexual recombination . . . genetic drift
(c) genetic drift . . . mutation . . . sexual recombination
(d) mutation . . . sexual recombination . . . natural selection
32. Birds with average-sized wings survived a severe storm more successfully than other birds in the same population with longer or shorter wings. This illustrates
(a) the founder effect (b) stabilizing selection
(c) artificial selection (d) gene flow
33. Which of the following scenarios would most likely result in microevolution of a population of humans?
(a) Only random mating took place in all people that reproduced in North America
(b) A colony of humans on the moon was isolated from earth
(c) The incidence of skin cancer in adults over age 40 rose significantly
(d) Both a and c
34. Which of the following is the best example of gene flow.
(a) A polyploid plant develops
(b) Genes are shuffled by crossing over of chromosomes during meiosis
(c) An earthquake results in the formation of a canyon splitting a population of
toads apart
(d) Wind blows pollen from one population of plants to another and cross fertilization
occurs
35. Stabilizing selection
(a) favors intermediate variants in a population
(b) prevents mutations from occurring
(c) occurs when some individuals migrate to an area with different environmental
conditions
(d) can only take place in species exhibiting sexual dimorphism
36. According to the Hardy-Weinberg theorem, the frequencies of alleles in a population would remain constant if ______________ is the only process that affects the gene pool.
(a) mutation (b) genetic drift
(c) sexual reproduction (d) microevolution
37. In the Hardy-Weinberg theorem p2 represents
(a) the total alleles in the gene pool
(b) the heterozygous dominants in the gene pool
(c) the homozygous recessives in the gene pool
(d) the homozygous dominants in the gene pool
38. In the Hardy-Weinberg theorem, 1 represents
(a) The total alleles in the gene pool
(b) the heterozygous dominants in the gene pool
(c) the homozygous recessives in the gene pool
(d) all the possible phenotypes in the gene pool
39. Two animals are considered of different species if they
(a) look different (b) cannot interbreed
(c) live in different h (d) are geographically isolated
40. Which of the following is the first step in allopatric speciation?
(a) genetic drift (b) geographical isolation
(c) polyploidy (d) hybridization
Answer
31. (d) 32. (b) 33. (b) 34. (d) 35. (a) 36. (c) 37. (d) 38. (a) 39. (b) 40. (b)
