Question

In a population of wild squirrels, most of them have gray fur, but an occasional squirrel is completely white. If we let P and p represent dominant and recessive alleles, respectively, of a gene that encodes an enzyme necessary for pigment formation, which of the following statements do you think is most likely to be correct?

A. The white squirrels are pp, and the p allele is a loss-of-function allele.
B. The gray squirrels are pp, and the p allele is a loss-of-function allele.
C. The white squirrels are PP, and the P allele is a loss-of-function allele.
D. The gray squirrels are PP, and the P allele is a loss-of-function allele.

Answer 1

The most likely correct statement is that the white squirrels are homozygous recessive (pp) and the p allele is a loss-of-function allele, resulting in no pigment formation and therefore white fur.

Step-by-step explanation:

Based on the principles of genetics and allele interactions, the description of gray and white fur in a population of wild squirrels corresponds to pigmentation inheritance patterns similar to what is seen in other organisms.

The statement that is most likely to be correct is A. The white squirrels are pp, and the p allele is a loss-of-function allele. This is because if an organism has two recessive alleles (homozygous recessive), and the trait in question requires a functional enzyme that the recessive allele does not produce, the resulting phenotype will express the recessive trait, in this case, the white fur.

Gray squirrels would have either the genotype PP or Pp, where the presence of at least one P allele provides the necessary enzyme for pigment formation resulting in the dominant phenotype - gray fur. Modeling this situation using punnett squares would show a typical Mendelian 3:1 phenotypic ratio of gray to white offspring if two heterozygous squirrels (Pp) were to mate.