[Campbell Biology P.341] A plant that is heterozygous for three independently assorting gene... | Practice Question

A plant that is heterozygous for three independently assorting genes flower position, stem length, seed shape with genotypes AaBbCc is allowed to self-fertilize. What proportion of the offspring would be expected to be homozygous for all three recessive traits aabbcc ?

  • A: 1/64
  • B: 1/32
  • C: 1/16
  • D: 1/8

Explanation

For each gene, the cross is Aa x Aa. The probability of getting a homozygous recessive offspring aa from this cross is 1/4. Since the three genes assort independently, we can use the multiplication rule. The probability of getting aabbcc is P aa P bb P cc = 1/4 1/4 1/4 = 1/64.