Download hardy-weinberg principle problems

HARDY-WEINBERG PRINCIPLE PROBLEMS
1. In a given population of organisms, the dominant allele (p) has a frequency of 0.7, and
the recessive allele (q) has a frequency of 0.3. Use the Hardy-Weinberg formula to
determine the genotype frequencies within the population.
2. In Tanzania, 4% of the population are homozygous for the sickle-cell anemia gene and
32% are heterozygous. From this data, calculate the proportion of alleles that are
recessive and dominant.
3. Ten percent of the genes for coat colour in a rabbit population are albino (b) while 90
percent code for black coat (B). What percentage of the rabbits are heterozygous if the
Hardy-Weinberg principle holds true?
4. In a population with two alleles for a particular trait, B and b, the allele frequency of B is
0.7. What would be the frequency of the three possible genotypes in the population?
5. In a population that is in equilibrium, 16% of the individuals show the recessive
phenotype. What is the frequency of the dominant allele in the population? What
proportion of the population is heterozygous for this trait?
6. The proportion of homozygous recessives of a certain trait in a large population is 0.09.
Assuming the gene pool is in equilibrium and all genotypes are equally successful in
reproduction, what proportion of heterozygous individuals would you expect to find in the
population?
7. Assume that Rh blood types are controlled by a single pair of alleles. Further, assume
that Rh-neg. individuals (rr) comprise 15% of a stable population of 1000 individuals.
Calculate the frequency of the alleles R and r and the expected genotype distribution.
8. In a small population, 30% is blood group M, 50% is blood group MN, 20% is of blood
group N. What are the gene frequencies??
9. In England the frequency of the i allele of the ABO blood group series is 0.6. What is the
frequency of the I allele (IA and IB combined)? What proportion of the population has
type O blood?
10. Among black Americans, the frequency of sickle cell anemia is about 0.0025. What is the
frequency of heterozygotes if sickle cell anemia is created by a recessive allele?
11. In a group of 812 individuals, 91% are tasters. The ability to taste PTC paper is dominant.
What are the gene frequencies in this population? What are the genotype frequencies?
12. Two pirates and three Polynesian beauties settled on a previously uninhabited tropical
island. All five of these settlers had brown eyes, but one man carried the recessive allele
for blue eyes. No new vagabonds arrive on the island and no one leaves this tropical
paradise. When the island population reaches 20,000 individuals, approximately how
many people would you expect to have blue eyes if you assume the population to be in
Hardy-Weinberg equilibrium?
13. Approximately one child in 10,000 is born with the recessive disease PKU
(phenylketonuria). What is the frequency of this allele in the population? What percent of
the population are carriers of this defective gene?