The results of a testcross reveal that all offspring resemble the parent being tested. That parent necessarily is
A) heterozygous.
B) polygenic.
C) homozygous.
D) recessive.
E) pleiotropic.

Question

Quizplus · Accepted Answer

A testcross involves crossing an individual with a homozygous recessive individual. If all offspring resemble the parent being tested, it indicates that the parent is homozygous, as there are no recessive alleles to produce different phenotypes.

The Results of a Testcross Reveal That All Offspring Resemble