Question

Some coat colour in cats are sex-linked and are associated with X-chromosome.Blck coat colour is codominant to ginger.Tortoiseshell coat colour is phenotypic expression to heterozygous condition.
A female ginger mates with an unknown male and whose daughter mates with a different unknown male to produce black coated female kitten and two male kitten, one with all black fur and other with all ginger fur

Explain the genetics associated with the generation of cats given by using Punnett square

Answer 1

X^G – ginger allele,

X^B – black allele,

X^BX^B – black female

X^GX^G – ginger female

X^GX^B - tortoiseshell female

X^GY – black male

X^BY – ginger male

The mother genotype is X^GX^G. As daughter inherits one X chromosome from mother, it has at least one X^G allele. However, as daughter offspring include black female, it also has X^B allele that was inherited from father.