Question

If you cross two walnuts, which of the following is impossible?

(a) Progeny to be a walnut

(b) Progeny to be a single

(c) Progeny to be a homozygous Rose

(d) Progeny to have a phenotype other than rose, single, pea or walnut

The question was asked in an online interview.

This interesting question is from Gene Interactions topic in division Extension and Deviation from Mendelian Genetic Principles of Cytogenetics

Answer 1

Right option is (d) Progeny to have a phenotype other than rose, single, pea or walnut

Easiest explanation: The gene interactions in case of chicken comb can only produce these four phenotypes in the ratio 9:3:3:1.