The Offspring of Two Heterozygous Gray-Bodied, Normal-Winged Flies Should Be

Multiple Choice

The offspring of two heterozygous gray-bodied, normal-winged flies should be 50% gray-bodied/normal wings (BbRr) and 50% black-bodied/vestigial wings (bbrr) because these alleles are linked. Suppose a small number, say 15%, of the offspring are instead black-bodied with normal wings. This is most likely the result of

A) crossing-over.
B) incomplete dominance.
C) codominance.
D) an error in meiosis.
E) mutation.