Question

In sweet pea a white substance is first converted to a ___________ substance by 1^st gene and that to a ______________ substance by 2^nd gene to give a purple flower.

(a) Yellow, purple

(b) Green, purple

(c) Purple, yellow

(d) White, yellow

I have been asked this question during an internship interview.

I want to ask this question from Duplicate Epistasis in chapter Extension and Deviation from Mendelian Genetic Principles of Cytogenetics

Answer 1

Right answer is (d) White, yellow

The explanation is: It is expected that in case of duplicate recessive epistasis of sweet pea plant a white substance is 1st converted to another white substance that is converted to purple substance in case of presence of two dominant genes. If any of these genes are absent this would give white flower.