In mice, agouti fur is a dominant trait resulting in individual hairs having a l

Question

In mice, agouti fur is a dominant trait resulting in individual hairs having a light band of pigment on an otherwise dark hair shaft. A mouse with agouti fur is shown here, along with a mouse with solid color fur, which is the recessive phenotype (A = agouti; a = solid color).
A separate gene, which is not linked to the agouti gene, can result in either a dominant black pigment or a recessive brown pigment (B = black; b = brown).

A litter of mice from the mating of two agouti black parents includes offspring with the following fur colors:
solid color, black
solid color, brown (sometimes called chocolate)
agouti black
agouti brown (sometimes called cinnamon)
In the same mouse species, a third unlinked gene (gene C/c) also has an epistatic effect on fur color. The presence of the dominant allele C (for color), allows the A/a and B/b genes to be expressed normally. The presence of two recessive alleles (cc), on the other hand, prevents any pigment from being formed, resulting in an albino (white) mouse.

Match the phenotypes on the labels at left to the genotypes listed below. Labels can be used once, more than once, or not at all.
?Label - Albino, Agouti brown, Sold color black, Agouti black, Solid color brown.
AaBbcc - ?
AaBBCC -?
Aabbcc -?
AAbbCc -?
aaBbCc -?
AABBcc-?

Explanation / Answer

The matching of the phenotypes with their respective labels are: AaBbcc - As the c allele is homozygous recessive, it does not allow the A/B genes to be expressed. Hence the phenotype is albino.
AaBBCC -As the c allele is homozygous dominant, it allows the A/B genes to be expressed. Hence the phenotype is Agouti black.
Aabbcc -As the c allele is homozygous recessive, it does not allow the A/B genes to be expressed. Hence the phenotype is albino.
AAbbCc -As the c allele is heterozygous, it allows the A/B genes to be expressed. Hence the phenotype is Agouti brown/cinnamon. aaBbCc -As the c allele is heterozygous, it allows the A/B genes to be expressed. Hence the phenotype is solid color black.
AABBcc-As the c allele is homozygous recessive, it does not allow the A/B genes to be expressed. Hence the phenotype is albino.

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