Epistasis is observed when the allele of one gene masks the effects of another gene. Use the Punnett square to answer the question.

AB Ab aB ab
AB
AABB

black

AABb

black

AaBB

black

AaBb

black

Ab
AABb

black

AAbb

brown

AaBb

black

Aabb

brown

aB
AaBB

black

AaBb

black

aaBB

yellow

aaBb

yellow

ab
AaBb

black

Aabb

brown

aaBb

yellow

aabb

?

What color would a dog's fur be if its genes are aabb?

(1 point)
Responses

yellow
yellow

brown
brown

white
white

black

1 answer

To determine the fur color of a dog with the genotype aabb, we refer to the given Punnett square and the outcomes it describes.

In the table, the combination of alleles leads to the following fur colors:

  • AABB: black
  • AABb: black
  • AAbb: brown
  • AabB: black
  • Aabb: brown
  • AaBB: black
  • AaBb: black
  • aaBB: yellow
  • aaBb: yellow
  • aabb: ?

From the phenotypes available, we can see that the aabb genotype corresponds to the last combination which is not explicitly listed, but based on the pattern observed (and other combinations leading to yellow), we can deduce that:

  • The presence of the recessive bb in combination with the recessive aa leads to yellow fur based on what is typically seen from dihybrid crosses in genetics.

Therefore, the color of a dog's fur with the genotype aabb would be:

yellow