A. The Hardy–Weinberg principle says that <span>genotype or allele frequencies in a population is constant from generation to generation as long as there isn't any evolutionary influences such as mutations, genetic drift, mate choice, etc. When such influences are not present, the genotype or allele frequencies will tend to an equilibrium - the number of the different alleles will be balanced. The </span>Hardy–Weinberg equation is p²+ 2pq+q²=1 where p is the dominant allele and q is the recessive allele. (p² represents homozygous dominant, 2pq represents heterozygous, and q² represents homozygous recessive.)<span>
B. Homozygous dominant=p</span>²=0.8²=0.64 500(total number of plants in the population)×0.64(percentage of homozygous dominant)=320 It would be expected to have 320 homozygous dominant plants.
Heterozygous=2pq=2×0.8×0.2=0.32 500(total number of plants in the population)×0.32(percentage of heterozygous)=160 It would be expected to have 160 heterozygous plants.
Homozygous recessive=q²=0.2²=0.04 500(total number of plants in the population)×0.04(percentage of homozygous recessive)=20 It would be expected to have 20 homozygous recessive plants.
Violet flowers correspond to the sum of all the homozygous dominant plants and the heterozygous plants, once the violet colour is dominant over the white colour. Violet flowers=320+160=480 White flowers correspond to the homozygous recessivet plants, once the violet colour is dominant over the white colour. White plants=20
