Question

Fruit color in squash is an example of?

• A. Recessive epistasis
• B. Dominant epistasis
• C. Complimentary genes
• D. Inhibitory genes

Answer 1

The correct option is B Dominant epistasis

Dominant epistasis is a condition when a dominant gene masks the effect of the other non-allelic gene. In summer squash, the fruit color may be white, yellow, or green. White fruits are produced by a domain epistatic allele 'W'. At another locus, Y for yellow fruits is dominant to its allele y for green fruits. Dominant white hides the effect of yellow or green. A consequence of this dominant epistasis is that the hybrid ratio is modified into 12 white: 3 yellow: 1 green. So, dominant epistasis suppresses the expression of a non-allelic gene (dominant or recessive). Thus, the correct answer is option B.