Explanation:
Here,a gene controls flower color:
R= purple flower color gene
r= white flower color gene
Number of purple flowering plants= 64
Number of white flowering plants= 36
Total number of flowering plants= 64+36=100
In this case it is clearly visible that purple color is dominant and white color is recessive(number of purple colored flowers are more)
According to Hardy Weinberg equilibrium sum of frequency of alleles(both dominant and recessive) is constant and given by,
p+q= 1
p is frequency of dominant allele(purple color of flower)
q is frequency of recessive allele(white color of flower)
Sum of frequency of genotypes (both dominant and recessive) is constant and given by
is frequency of dominant genotype(purple colored flowers)
is frequency of recessive genotype(white colored flowers)
2pq is frequency of heterozygous genotype
Frequency of dominant genotype() can be calculated as:
number of purple flowering plants/total number of flowers
=64/100
= 0.64
=
= 0.8
hence value of p will be 0.8