Question

F₁ offspring of the monohybrid cross AA × aa are ______.

Options

• all AA

• all Aa

• all aa

• 1/2 AA and 1/2 aa

Answer 1

F₁ offspring of the monohybrid cross AA × aa are all Aa.

Explanation:

When a monohybrid cross is done between homozygous dominant (AA) and homozygous recessive (aa) individuals, all the F₁ offspring will be heterozygous (Aa). This is because each offspring receives one dominant allele (A) from the AA parent and one recessive allele (a) from the aa parent. As a result, the genotype of all F₁ offspring will be Aa, expressing the dominant trait but carrying the recessive allele as well.