Worksheet Unit 13 BIO1020

Gene frequencies

1. If yellow seed color is dominant to green seed color in pea plants and a population of 100 plants includes 16 individuals with green seeds, what is the gene frequency of the allele for green seed color? (You may assume that the population is in Hardy-Weinberg equilibrium)

If 16% of the population has green seeds (homozygous recessive), then q2=0.16 q (Frequency of the allele for green seed) =√q2 = 0.4

2. If a population is in Hardy-Weinberg equilibrium with a gene frequency of 0.2 for the dominant allele, what frequency would you expect for the recessive allele in the F2 generation?

p =0.2, then p + q = 1, q = 1- pq = 1 - 0.2 = 0.8

3. If straight hair is dominant in humans to curly hair and 64% of a population has straight hair, what proportion of the population would you expect to be heterozygous, provided the population meets the assumptions of the Hardy-Weinberg Law?

If 64% of the population has straight hair (dominant trait), then the balance of the population (36%) has curly hair (recessive trait). If 36% is q2= 0.36, then q=0.6 and the heterozygote are represented by 2pq, or 2(0.4) (0.6) =0.48

4. In yellow perch, an orange dorsal fin is dominant to yellow. Imagine a population of perch where 36% of all individuals have orange fins. If all of the assumptions of the Hardy-Weinberg Law are met, what is the frequency of homozygous dominant individuals in this population?

q2 = 1 – p 2= 1 - 0.36 = 0.64, so √0.64 = 0.8, q = 0.8, p = 0.2, then p 2= 0.04 or 4%

5. What does “q2” represent in the Hardy-Weinberg Law (p2 + 2pq + q2 = 1)?Frequency of homozygous recessive genotype

Worksheet Unit 13 Name________________________Gene frequencies

1. If yellow seed color is dominant to green seed color in pea plants and a population of 100 plants includes 16 individuals with green seeds, what is the gene frequency of the allele for green seed color? (You may assume that the population is in Hardy-Weinberg equilibrium)

2. If a population is in Hardy-Weinberg equilibrium with a gene frequency of 0.2 for the dominant allele, what frequency would you expect for the recessive allele in the F2 generation?

3. If straight hair is dominant in humans to curly hair and 64% of a population has straight hair, what proportion of the population would you expect to be heterozygous, provided the population meets the assumptions of the Hardy-Weinberg Law?

4. In yellow perch, an orange dorsal fin is dominant to yellow. Imagine a population of perch where 36% of all individuals have orange fins. If all of the assumptions of the Hardy-Weinberg Law are met, what is the frequency of homozygous dominant individuals in this population?

5. What does “q2” represent in the Hardy-Weinberg Law (p2 + 2pq + q2 = 1)?