Question

Assume that hair color can only be brown or red and follows the principles of simple dominant recessive inheritance. The dominant allele (B) corresponds to the color brown, and the recessive allele (r) corresponds to the color red. If the mother is heterozygous, and the father is homozygous for brown hair, What is the probability of having a child with the red hair phenotype?

A) 0%
B) 25%
C) 50%
D) 75%

Answer 1

The probability of having a child with the red hair phenotype is 0%.

Step-by-step explanation:

In simple dominant recessive inheritance, the dominant allele (B) for brown hair color is expressed over the recessive allele (r) for red hair color. If the mother is heterozygous (Bb) and the father is homozygous for brown hair (BB), then the Punnett square can be used to determine the probability of having a child with the red hair phenotype:

Bb (mother) x BB (father)

The possible genotypes of the offspring are:

• BB (brown hair)
• Bb (brown hair)

Therefore, there is a 0% probability of having a child with the red hair phenotype (rr), making option A) 0% the correct answer.