Question

Posted this 3 times, please help ASAP!

In cats, fur color is X-linked. Black fur is dominant to yellow fur; he heterozygote produces tortoiseshell fur.

a. Cross a tortoise shell female with a yellow male.

b. Cross a black male with a yellow female.

Please show the steps!

Answer 1

Since black fur is dominant to yellow fur, represent them with X and x respectively.

(Ideally you would draw a Punnett square as part of your answer but it’s hard for me to do here.)

For part a:

They are saying the cross is Xx with xY. Taking one allele from each parent you have the following combinations:

1 Xx : 1 XY : 1 xx : 1 xY
1 tortoise female : 1 black male : 1 yellow female : 1 yellow male

For part b:

They are saying the cross is XY with xx. Taking one allele from each parent you have the following combinations:

2 Xx : 2 xY
2 tortoise female : 2 yellow male