Why is the Hardy-Weinberg principle useful to biologists?

Why is the Hardy-Weinberg principle useful to biologists?
  a. It describes most populations.
  b. It proves that Mendel was correct for populations.
  c. It explains the existence of variation in populations.
  d. It explains the existence of a large number of species.
  e. It identifies those factors that can change allele or genotype frequencies

Question 2

What does p2 represent within the Hardy-Weinberg equation?
  a. The total alleles in a gene pool
  b. The heterozygotes in a population
  c. The recessive allele at a given locus
  d. The dominant alleles in a given population
  e. The homozygous dominant genotype at a given locus