BIOLOGY 1B-Evolution_Practice questions

BIOLOGY 1B-Evolution_Practice questions Practice questions for the Evolution midterm 01) The recessive phenotype of a trait occurs in 16% of a population. What is the frequency of the dominant allele? a) 0.16 b) 0.36 c) 0.40 d) 0.48 e) 0.60 02) In a large population of randomly reproducing rabbits, a recessive allele r comprises 80% of the alleles for a gene. What percentage of the rabbits would you expect to have the recessive phenotype? a) 4% b) 32% c) 64% d) 80% e) 100% 03) A population of flowers is in Hardy-Weinberg equilibrium with an allele frequency for white flowers (w) of 40%. What percentage of the flowers will have the colored (Ww) or dominant (WW) phenotype? a) 16% b) 25% c) 40% d) 60% e) 84% 04) A fur color gene in mice has a white dominant allele (W) and a brown recessive allele (w). Imagine that the environment changes suddenly and none of the white mice survive. In a population of 10,000 mice the initial frequency of W in the pool was 0.7. How many generations would be required to eliminate all W alleles from the population? Assume that there is no mutation and the population meets all other Hardy-Weinberg conditions. a) 1 b) 2 c) 5 d) 20 e) the W alleles can never be eliminated 05) The genetic preservation of the features that increase the likelihood of survival and reproduction of some individuals within a population is called the process of: a) evolutionary resistance b) outcrossing c) speciation d) natural selection e) genetic drift 2 06) Some flowering plants cannot self-pollinate which increases their tendency to mate with phenotypically different individuals, a process called disassortative mating. What effect would this have on a population in Hardy-Weinberg equilibrium? a) No change in genotype frequencies would be observed. b) An increase in homozygotes would be observed. c) A decrease in heterozygotes would be observed. d) An increase in heterozygotes would be observed. 07) Certain small towns in the western United States have remained isolated and inbred since their settlement many years ago. Some alleles are more common in these communities as compared to the rest of the population. This effect is known as: a) directional selection b) disruptive selection c) founder effect d) Hardy-Weinberg effect 08) The California populations of the Northern elephant seal are descendants from a very small population of seals that was over-hunted in the 1890s. Heterozygosity in this population would be expected to be _____due to _____. a) high; disruptive selection b) high; assortative mating c) low; the founder effect d) low; a bottleneck effect e) this cannot be determined from the information given 09) Two parents who do not have sickle cell anemia have a child that has the disease. The parents are both: a) Homozygous for the sickle cell allele b) Heterozygous for the sickle cell allele c) Homozygous for the normal allele d) Epistatic for the sickle cell allele e) Pleiotropic for the sickle cell allele 10) Animals that select mates that are phenotypically similar will have _____ when compared with Hardy-Weinberg predictions. a) more mutations b) more homozygotes c) more heterozygotes d) fewer homozygotes e) less natural selection 3 11) Gene flow, defined as the movement of genes from one population to another, can take place by migration, as well as: a) mating between individuals with similar traits.. b) mating between individuals of adjacent populations. c) mating between individuals with dominant phenotypes. d) movement of genes within individuals by transposons (horizontal gene transfer). e) removal of the physical barriers between populations. 12) Environmental