Question

In a random mating population frequency of dominant allele is $0.7$. What will be the frequency of homozygous dominant phenotype?

• A. $0.49$
• B. $0.09$
• C. $0.3$
• D. $0.21$

Answer 1

The correct option is B $0.09$

The basic formulas: 𝑝*𝑝 + 2𝑝𝑞 + 𝑞*𝑞and 𝑝 + 𝑞 = 1

q = frequency of the recessive allele in the population

p = frequency of the dominant allele in the population

q*q = frequency of homozygous recessive individuals

p*p = frequency of homozygous dominant individuals

2pq = frequency of heterozygous individuals

Thus, frequency of recessive allele: 𝑞 = 1 − 𝑝 = 1 − 0.7 = 0.3.

Frequency of recessive phenotype: 𝑞*𝑞 = 0. 3*0. 3 = 0.09.

So, the correct option is '0.09'.