Monohybrid Cross Quiz 2

In a monohybrid cross, an organism must have __________ recessive alleles to express a recessive trait.

• both (aa)

• only one (Aa)

• None (AA)

Which genotype would result in an organism showing a recessive trait?

• AA

• Aa

• aa

• AA or Aa

In pea plants, yellow seeds (Y) are dominant to green seeds (y). A heterozygous plant is crossed with a homozygous recessive plant. What percentage of offspring will have green seeds?

• 0%

• 25%

• 50%

• 75%

In horses, black coat color (B) is dominant to chestnut coat color (b). Two horses with chestnut coats are crossed. What percentage of the offspring are expected to have black coats?

Widow’s peak hairline (W) is dominant to a straight hairline (w). If a person who is heterozygous for a widow’s peak has children with a person who has a straight hairline, what percentage of their children are expected to have a widow’s peak?

In tomato plants, red fruit (R) is dominant to yellow fruit (r). If both parents were heterozygous for this trait, What percentage of the offspring are expected to produce yellow fruit?