Cross of two yellow mice will give _____________ normal mouse.

cross-of-two-yellow-mice-will-give-normal-mouse

Cross of two yellow mice will give _____________ normal mouse.

A. 1/4

B. 2/4

C. 1/3

D. 2/3

This question was addressed to me by my college professor while I was bunking the class.

I’m obligated to ask this question of Lethal Alleles in section Extension and Deviation from Mendelian Genetic Principles of Cytogenetics

Correct option is C. 1/3

Explanation: Homozygous condition of the yellow allele will lead to lethality thus the living yellow mouse are heterozygous. Their cross will give 1/4^th of homozygous yellow allele mice which will die changing the proportion of normal mice to 1.3^rd of the living ones.