Directions: The table lists the hair color and genotype of six individuals where black hair is dominant over blond. Use the table to answer any questions that follow.

Question

Directions: The table lists the hair color and genotype of six individuals where black hair is dominant over blond. Use the table to answer any questions that follow.

HAIR COLOR
Name Hair color Alleles
Mr. Johnson black homozygous
Mrs. Johnson blond homozygous
Mr. Valdez blond heterozygous
Mrs. Valdez black heterozygous
Mr. Ellwood black heterozygous
Mrs. Ellwood blond homozygous

If Mr. and Mrs. Johnson had four children together, what color of hair would the children likely have?

a
All 4 of the children would have black hair.
b
Only 3 of the children would have black hair, and 1 child would have blond hair.
c
All 4 of the children would have blond hair.
d
Only 2 of the children would have black hair, and 2 of the children would have blond hair

Answer 1

The correct answer is d. Only 2 of the children would have black hair, and 2 of the children would have blond hair. This is because Mr. Johnson has black hair (homozygous) and Mrs. Johnson has blond hair (homozygous). When they have children, there is a 50% chance that each child will inherit the black hair allele from Mr. Johnson and a 50% chance that each child will inherit the blond hair allele from Mrs. Johnson. Therefore, half of the children are likely to have black hair and half are likely to have blond hair.