Question

A pure-breeding strain of guinea pig with black fur is crossed to a pure breeding strain with white fur. A number of possible progeny phenotypes are listed below. What would each phenotype indicate about the dominance relationship between alleles of this locus?

(i) All the progeny are white [1 mark]

(ii) All the progeny are black [1 mark]

(iii) All the progeny are grey [1 mark]

(iv) All the progeny have patches of white and black fur [1 mark]

Answer 1

Answer:

(i) All the progeny are white: It indicates complete dominance of white allele over black allele

(ii) All the progeny are black: It indicates complete dominance of black allele over white Allele.

(iii) All the progeny are grey: it indicates the incomplete dominance. Neither allele is dominant or receive.

(iv) All the progeny have patches of white and black fur: It indicates codominance of the two alleles. Each allele is equally dominant.