Answer: 0.49
Explanation: In Hardy-weinberg, the population is in equilibrium, which means the expected proportions for the genotype is expressed as:
(p+q)² = 1 or p²+2pq+q² = 1, where
p is the frequency of the dominat allele;
q is the frequency of the recessive allele;
If the frequency of the allele a is 0.70, it means q=0.70.
To find the percentage who is recessive homozygous:
q² = (0.70)² = 0.49
Therefore, the percentage of population homozygous for allele a is 0.49