Question

Explain inheritance of fruit colour in Cucurbita pepo.

Answer 1

Inheritance of fruit colour in Cucurbita pepo is an example of dominant epistasis.

Dominant epistasis- it happens when dominant allele of one gene masks the expression of all alleles of other genes.

Fruit and flower colour in cucurbita plant is a common example to illustrate dominant epistasis. As shown in the figure squash comes in three colours. Yellow(AA, Aa) is dominant over green(aa). However, since squash colour polygenic, Or detemined by more than one gene, gene B also determines squash colour. Because gene B shows epistatsis, it is more important than gene A in determining squash colour. This is an example of a bully masking the expression of another gene.