Question

In rats, hair color is either gray (G), black (g), or white. The white color is produced due to an epistatic recessive allele of gene "a". Two heterozygous Gray rats are crossed. Both rats are also heterozygous for the epistatic gene. Predict the probability that an offspring of this cross will:

a. Express the gray phenotype
b. Express the black phenotype
c. Express the white phenotype

Answer 1

The probability of offspring expressing gray, black, or white phenotype in the given cross can be predicted using Punnett square analysis. The white phenotype will not be expressed in this cross.

Step-by-step explanation:

To predict the probability of offspring expressing different hair color phenotypes in the given cross, we need to use Punnett square analysis. Since both parent rats are heterozygous for the gray coat color (Gg), we can set up a Punnett square using Gg as the genotype for both parents.

When we cross the heterozygous gray rats, the possible genotypes and phenotypes of the offspring are:

• Gray (GG) genotype - gray phenotype
• Gray (Gg) genotype - gray phenotype
• Gray (Gg) genotype - gray phenotype
• Black (gg) genotype - black phenotype

Since the white phenotype is produced by the epistatic recessive allele of gene 'a', it will not be expressed in this cross. Therefore, there is no chance of an offspring expressing the white phenotype.