The results of a test cross reveal that all the offspring resemble the parent being tested. This parent must be
A) self-pollinated.
B) recessive.
C) haploid.
D) homozygous.
E) heterozygous.

Question

Quizplus · Accepted Answer

In a test cross, one parent is crossed with another parent that is homozygous recessive for the trait in question. If all offspring resemble the parent being tested, it indicates that the tested parent must also be homozygous (either dominant or recessive) for that trait, as no variation is observed in the offspring.

The Results of a Test Cross Reveal That All the Offspring