1.In a Hardy-Weinberg population with two alleles, A and a, the frequency of allele “a” is 0.05. What is the frequency of individuals with AA genotype?

2.In a hypothetical population of 1000 people, tests show that 640 have the genotype RR, 320 have the genotype Rr, and 40 have the genotype rr.

• What is the frequency of the R allele? The r allele?

3. A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several generations, 2.25% of the animals display a recessive phenotype (aa), the same percentage as at the beginning of the

breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants.

• What is the most reasonable conclusion that can be drawn from the fact that the frequency of the recessive trait (aa) has not changed over time?

–A) The population is undergoing genetic drift.

–B) The two phenotypes are about equally adaptive under laboratory conditions.

–C) The genotype AA is lethal.

–D) There has been a high rate of mutation of allele A to allele a.

–E) There has been sexual selection favoring allele a.

•What is the estimated frequency of allele a in the gene pool?

•What is the estimated frequency of allele A in the gene pool?

•What is the estimated percentage of individuals that are homozygous dominant in this population?

•What is the estimated percentage of individuals that are heterozygous in this population?

4. Assume that it has been determined within a particular ethnic group, 1 out of 32 births will have a serious autosomal recessive genetic disease.

• What is the percentage of children with this disease?

• What is the frequency of the normal allele?

• What percent of the population will be carriers for this recessive disease?