Cross of two yellow mice will give _____________ normal mouse.

Question

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&#8217;m obligated to ask this question of Lethal Alleles in section Extension and Deviation from Mendelian Genetic Principles of Cytogenetics

fahmy · Accepted Answer

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.