Question

Assume a population of purple and white flower pea plants (2000 total plants) is in Hardy-Weinberg equilibrium. The frequency of white flower plants is 0.16. On the basis of this information, determine the following:
a. The frequency (decimal form) of heterozygous purple plants. Round to 2 significant digits.

b. The frequency (decimal form) of the dominant allele (1 significant digit).

c. The number of homozygous purple flower plants.

I tried to take 2pg = 2(0.84)(0.16) for part A and got 0.268 (approximately 0.27) for the heterozygous purple flower but that was incorrect.4

Answer 1

Answer:

a) $0.48$

b)

$p= 0.4\\q=0.6$

c) $720$

Explanation:

Given ,

Frequency of white flower plant ($p^2$) is $0.16$

Thus, frequency of dominant white allele ($p$) is equal to $\sqrt{0.16} \\= 0.4$

As we that, as per  Hardy-Weinberg equilibrium equation

$p+q=1$

Substituting the value of $p$ in above equation, we get

$0.4+q=1\\q=1-0.4\\q=0.6$

a) As per Hardy-Weinberg equilibrium equation

$p^2+q^2+2pq=1$

Substituting the given and calculated values in above equation, we get -

$0.4^2+0.6^2+2pq=1\\0.16+0.36+2pq=1\\2pq=1-0.16-0.36\\2pq=0.48$

b) The frequency (decimal form) of the dominant allele

$p= 0.4\\q=0.6$

c) number of homozygous purple flower plants

$=$ frequency of purple flower plants ($q^2$) $*$ Number of flowers

$= q^2 * 2000\\= (0.6^2)*2000\\= 0.36 * 2000\\= 720$