The fact that fur colour can be tortoise means that both phenotypes are expressed, as a result of codominance of the genotypes black and orange.
Since we are given that fur colour is controlled by X-linked alleles, it means that tortoise can only be inherited in females (XX) where there are two X-alleles. In males (XY), the only X-allele will control the fur colour, namely black or orange.
If
O=orange
B=black
Y=Y-allele (from male only), irrelevant in fur colour.
Then the male parent is OY (orange), and the female parent is OB (tortoise).
Resulting in F1 as
OY (orange male)
BY (black male)
OB (tortoise female)
OO (orange female)
exactly as given in the question above.
In cats fur colour can be black, orange or tortoise (patched orange and black). A mating
between two cats produces the kittens indicated below.
P: tortoise female X orange male
F1: orange females
tortoise females
black males
orange males
What are the genotypes of the parents and F1 progeny, if fur colour is controlled by X-linked
alleles?
1 answer