In the same mouse species, a third unlinked gene (gene C/c) also has an epistati
ID: 18276 • Letter: I
Question
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.
agouti
solid color
solid color
agouti black
albino
AaBbcc
AaBBCC
Aabbcc
AAbbCc
aaBbCc
AABBcc
Explanation / Answer
Since the presence of two recessive alleles (cc), prevents any pigment from being formed, the mouse with their genotypes containing (cc) will result in an albino (white) mouse.
AaBbcc - albino
Aabbcc - albino
AABBcc - albino
The presence of the dominant allele C (for color), allows the A/a and B/b genes to be expressed normally. Therefore,
AaBBCC - agouti black
AAbbCc - agouti brown
aaBbCc - solid color, black