Question

Self crossing a white flower of sweet pea would give a ____________________

(a) White flower only

(b) Equal probability of white or purple

(c) More white flower than purple

(d) Purple flowers only

I got this question in an international level competition.

Asked question is from Duplicate Epistasis topic in section Extension and Deviation from Mendelian Genetic Principles of Cytogenetics

Answer 1

Correct choice is (a) White flower only

To explain I would say: The white flower arises due to a homozygous recessive condition in atleast one of the two gene locus. In this case self crossing can never yield a combination of heterozygous or homozygous dominant at that gene locus, so it will only give white flowers.