Question

In mice, agouti coloration (A) is a dominant trait for fur color over black fur

(aA Punnett square diagram is provided. A particular generation of
offspring has a ratio of three agouti individuals to one black individual.
Which of the following genotype combinations is possible for the parent



A: aa x aa

B: AA x Ar

C:Aa x Aa

D: AA x AA

Answer 1

Answer: C) Aa x Aa

I got it right!

Answer 2

C. Aa x Aa

Step-by-step explanation:

According to this question, one gene coding for fur coloration in mice is involved. The allele for agouti coloration (A) is a dominant trait over black fur (a). This means that a heterozygote mouse will have an agouti coloration.

Based on this question, two parents were crossed to produce offsprings that have a ratio of three agouti individuals (3) to one black individual (1). Based on this phenotypic ratio, only parents that are both heterozygous for the fur color gene can produce it. That is, a cross between Aa and Aa mice parent. Hence, the genotype combination of Aa × Aa is possible for the parent to produce offsprings with 3 Agouti : 1 black.