Question

In peas, a gene controls flower color such that R = purple and r = white. In an isolated pea patch, there are 75 purple-flowering plants and 25 white-flowering plants. Assuming Hardy-Weinberg equilibrium, what is the value of q for this population? Group of answer choices

0.75

0.25

0.50

0.05

Answer 1

The correct answer is 0.50.

Explanation: In the Hardy- Weinberg equilibrium, the sum of the dominant allele frequency (p) and the recessive allele frequency (q) is equal to 1.

p + q = 1

R= purple, means 'RR' (pp, homozygous dominant)

r = white, means 'rr' (qq, homozygous recessive)

Here, the question says that 25 white flowering plants with homozygous recessive gene, therefore, the recessive genotype frequency is equals to 0.25

But, the question asked is recessive allele frequency. So q² = 0.25 then q will be 0.50