Question

In guinea pigs, the allele for black eyes (B) is dominant over the allele for red eyes (b). Which Punnett square correctly predicts the outcome of a cross between a purebred black-eyed parent and hybrid black-eyed parent? A. BB. B. Bb. C. BB. D. Bb .

Answer 1

A Punnett square predicts genetic outcomes. For parents with genotypes BB and Bb, black eye color being dominant, all offspring would be black-eyed but half will be purebred (BB) and half will be hybrids (Bb).

Step-by-step explanation:

The student is asking about the genetic outcome of cross-breeding two guinea pigs, where the allele for black eyes (B) is dominant over the allele for red eyes (b). The parents involved are a purebred black-eyed parent (BB) and a hybrid black-eyed parent (Bb). To predict the outcome of their offspring's eye color, we use a Punnett square, a graphical representation of possible genetic outcomes.

In this case, the Punnett square would be arranged as follows: the alleles of the purebred parent (BB) are written along the top, and the alleles of the hybrid parent (Bb) are written along the side. The potential offspring combinations are then recorded within the square: BB, Bb, BB, and Bb.

Therefore, all offspring would inherit at least one dominant allele (B) for black eyes, resulting in a 100% probability of having black eyes. However, the Punnett square also demonstrates a 50% chance of the offspring being hybrid black-eyed (Bb) and a 50% chance they will be purebred black-eyed (BB).

Learn more about Punnett Square