K.C.S.E Biology Q & A - MODEL 2019PP2QN04

K.C.S.E Biology Q & A - MODEL 2019PP2QN04

In cats, the gene for fur colour is sex-linked. Letter G represents the gene for ginger fur colour while letter B represents the gene for black fur colour in a given cat species. These genes are co-dominant. Heterozygous females have ginger and black patches of fur and their phenotype is described as tortoise-shell.

​(a) With reference to the information given above, what is meant by the term co-dominance? 
(b) Explain why male cats with a tortoise-shell phenotype do not usually occur. 
(c) A tortoise-shell female was crossed with a black male. Determine the genotypes and phenotypes of the offspring.

answers