In a testcross, an organism with a dominant phenotype, but unknown genotype, is crossed with an organism that is
A) homozygous dominant.
B) heterozygous.
C) homozygous recessive.
D) heterozygous dominant.
E) monohybrid dominant.

Question

Quizplus · Accepted Answer

In a testcross, the unknown genotype organism is crossed with a homozygous recessive organism. This allows for the determination of the unknown genotype by observing the phenotype of the offspring. If the unknown organism is homozygous dominant, all offspring will have the dominant phenotype. However, if the unknown organism is heterozygous, only half of the offspring will have the dominant phenotype.

In a Testcross, an Organism with a Dominant Phenotype, but Unknown