Question

Which of the following is not true for yellow mice?

(a) The homozygous yellow mice die

(b) A normal ice crossed to yellow mice will always give normal probabilities of F1

(c) In yellow mice the yellow coloring allele is under control of Raly promoter

(d) The homozygous mouse dies as the yellow allele is produced in excess

I have been asked this question in quiz.

I'd like to ask this question from Lethal Alleles in chapter Extension and Deviation from Mendelian Genetic Principles of Cytogenetics

Answer 1

The correct answer is (d) The homozygous mouse dies as the yellow allele is produced in excess

The best I can explain: In homozygous condition the mice die not due to over expression of agouti, or yellow coloring gene but due to absence of expression of Raly gene.