[Campbell Biology P.540] In a population in Hardy-Weinberg equilibrium, if the frequency of ... | Practice Question

In a population in Hardy-Weinberg equilibrium, if the frequency of the CR allele p is 0.8 and the CW allele q is 0.2, what are the expected frequencies of the CRCR, CRCW, and CWCW genotypes in the next generation, respectively?

  • A: 80% CRCR, 20% CWCW, 0% CRCW
  • B: 64% CRCR, 32% CRCW, 4% CWCW
  • C: 64% CRCR, 16% CRCW, 4% CWCW
  • D: 32% CRCR, 64% CRCW, 4% CWCW

Explanation

According to the Hardy-Weinberg principle, the genotype frequencies are calculated as: CRCR = p² = 0.8 ² = 0.64 64% ; CRCW = 2pq = 2 0.8 0.2 = 0.32 32% ; CWCW = q² = 0.2 ² = 0.04 4% .