In the mouse,gene A allows pigmentation to be deposited in the individual coat hairs; its allele a prevents such deposition of pigment,resulting in an albino.Gene B gives agouti wild- type fur ; its allele b gives black fur.What would the expected ratio of the progeny be in a cross of a doubly heterozygous agouti mouse mated with a doubly homozygous recessive white mouse?
A)1 agouti :1 black :1 albino
B)9 black : 27albino
C)1 agouti :1 black : 2 albino
D)3 agouti :4 black : 9 albino
E)9 agouti :3 black : 4 albino

Question

In the mouse,gene A allows pigmentation to be deposited in the individual coat hairs; its allele a prevents such deposition of pigment,resulting in an albino.Gene B gives agouti wild- type fur ; its allele b gives black fur.What would the expected ratio of the progeny be in a cross of a doubly heterozygous agouti mouse mated with a doubly homozygous recessive white mouse?
A)1 agouti :1 black :1 albino 
B)9 black : 27albino 
C)1 agouti :1 black : 2 albino 
D)3 agouti :4 black : 9 albino 
E)9 agouti :3 black : 4 albino

Quizplus · Accepted Answer

The doubly heterozygous agouti mouse (AaBb) crossed with a doubly homozygous recessive white mouse (aabb) would produce a 1:1:2 ratio of agouti:black:albino offspring. This is because the A allele is necessary for any pigmentation, and without it (aa), the mouse will be albino regardless of the B gene's status. The B gene then determines the color of the pigmented mice, with B resulting in agouti and b resulting in black.

In the Mouse,gene a Allows Pigmentation to Be Deposited in the Individual