Question

grey horse cat is governed by the dominant gene G and non-grey coat by its recessive allele g. black horse coat is governed by an independently assorting gene E and chestnut by its recessive gene e. when dihybrid horses (multiple pairs) were crossed over a number of years, 620 offspring had a grey coat, 138 with black coat and 52 with chestnut coat.

a) what phenotypic ratio can be deduced from the above data?

b) what type of epistatic interaction (if any) is operative? explain in words, and show a Punnett square to back up your explanation.

Answer 1

a) what phenotypic ratio can be deduced from the above data?

The ratio almost fit to 12 : 3 : 1.

b) what type of epistatic interaction (if any) is operative? explain in words, and show a Punnett square to back up your explanation.

The epistatic interaction is Dominant epiststis.

In dominant epistatis one gene masks the expression of other gene. the gene which masks the expresson of other gene is reffered as epistatic gene. The epiststic gene can express itself but the other gene expresses only when the epistatis gene is in recessieve condition.

Instead of chisquare test, we have provided the punnet square to give a clear idea...