A child is born with dwarfism (tt). His parents are of normal height. Which of the following must be TRUE of the parents?
A) They are both homozygous recessive dwarf.
B) They are both heterozygous tall.
C) They are both heterozygous dwarf.
D) They are both homozygous dominant tall.

Question

Quizplus · Accepted Answer

Since the child has dwarfism and is homozygous recessive (tt), each parent must have contributed one recessive allele (t). This means both parents are carriers of the dwarfism allele but do not express the trait themselves, indicating they are heterozygous tall (Tt).

A Child Is Born with Dwarfism (Tt)