Question

In cats, curled ears result from an allele, Cu, that is dominant over an allele cu, for normal ears. 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 with a homozygous black cat with normal ears. All the F1 cats are black and have curled ears.What phenotypes and proportions are expected from teh following two crosses?1 - Two of the F1 cats mate?2 - An F1 cat mates with a stray cat that is gray and possesses normal ears.a. 1/4 black cats, curled ears; 1/4 black cats, normal ears; 1/4 gray cats, curled ears; and 1/4 gray cats normal earsb. 9/16 gray cats, normal ears; 3/16 gray cats, curled ears; 3/16 black cats, normal ears; and 1/16 black cats, curled earsc. 9/16 black cats, curled ears; 3/16 black cats, normal ears; 3/16 gray cats, curled ears; and 1/16 gray cats, normal earsd. All gray cats, normal earse. All black cats, curled ears.

Answer 1

Answer:

Explanation:

Cross : ggCuCu X GGcucu --------Parents

F1 progeny : GgCucu

Two of the F1 cats mate :

Cross : GgCucu X GgCucu

Gametes :

Gg X Gg = GG, Gg, Gg, gg

Cucu X Cucu = CuCu, Cucu, Cucu, cucu

1/4 GG X 1/4 CuCu = 1/16 GGCuCu (black - curled ears)

1/4 GG X 2/4 Cucu = 2/16 GGCucu (black - curled ears)

1/4 GG X 1/4 cucu = 1/16 GGcucu (black - normal ears)

2/4 Gg X 1/4 CuCu = 2/16 GgCuCu (black - curled ears)

2/4 Gg X 2/4 Cucu = 4/16 GgCucu (black - curled ears)

2/4 Gg X 1/4 cucu = 2/16 Ggcucu (black - normal ears)

1/4 gg X 1/4 CuCu = 1/16 ggCuCu (gray - curled ears)

1/4 gg X 2/4 Cucu = 2/16 ggCucu (gray - curled ears)

1/4 gg X 1/4 cucu = 1/16 ggcucu (gray - normal ears)

Answer : (i). 9/16 black cats, curled ears; 3/16 black cats, normal ears; 3/16 gray cats, curled ears; and 1/16 gray cats, normal ears.

An F1 cat mates with a stray cat that is gray and possesses normal ears :

Cross : GgCucu X ggcucu

Gametes :

Gg X gg = Gg, Gg, gg, gg

Cucu X cucu = Cucu, Cucu, cucu, cucu

2/4 Gg X 2/4 Cucu = 4/16 GgCucu (black - curled ears)

2/4 Gg X 2/4 cucu = 4/16 Ggcucu (black - normal ears)

2/4 gg X 2/4 Cucu = 4/16 ggCucu (gray - curled ears)

2/4 gg X 2/4 cucu = 4/16 ggcucu (gray - normal ears)

Answer : (i). 1/4 black cats, curled ears; 1/4 black cats, normal ears; 1/4 gray cats, curled ears; 1/4 gray cats, normal ears.