In cats, curled ears (Cu) results from an allele that is dominant over an allele for
normal ears (cu). Black color results from an independently assorting allele (G) that
is dominant over an allele for gray (g). A gray cat homozygous for curled ears is
mated to a homozygous black cat with normal ears. All the F1 cats are black and
have curly ears.
(a) If two of the F1 cats mate, what phenotypes and proportions are expected in the
F2?
If F1 cats mated, GgCucu × GgCucu, then following proportions and
phenotypes are expected in the F2:
9/16 Black with curly ears
3/16 Black with normal ears
3/16 Gray with curly ears
1/16 Gray with normal ears
(b) An F1 cat mates with a stray cat that is gray and possesses normal ears. What
phenotypes and proportions of progeny are expected from this cross?
The mating of a F1 cat (GgCucu) with a gray cat with normal ears (ggcucu) is a
testcross in which we would expect to produce equal numbers of all the
different progeny classes:
¼ Black with curly ears
¼ Black with normal ears
¼ Gray with curly ears
¼ Gray with normal ears