How does gene C/c affect the expression of gene A/a in pigmentation of mice?
It enhances the expression of gene A/a
It masks the expression of gene A/a in homozygous recessive condition
It masks the expression of gene A/a in homozygous dominant condition
It has no effect on the expression of gene A/a
Option b is correct because
In pigmentation of mice, gene C/c is epistatic to gene A/a. This means that the expression of gene A/a is masked by gene C/c in homozygous recessive condition. When gene C/c is homozygous recessive, it masks the formation of any color and albino/white coat is produced, regardless of the allele present at locus A. Therefore, option B is the correct answer.
Option A is incorrect because gene C/c does not enhance the expression of gene A/a.
Option C is incorrect because gene C/c masks the expression of gene A/a in homozygous recessive condition, not homozygous dominant condition.
Option D is incorrect because gene C/c does have an effect on the expression of gene A/a, as it masks its expression in homozygous recessive condition.