Problem:
Question: What is a testcross?
A) a mating between an individual of unknown genotype and an individual homozygous recessive for the trait of interest
B) a mating between an individual of unknown genotype and an individual homozygous dominent for the trait of interest
C) a mating between an individual of unknown genotype and an individual hterozygous for the trait of interest
D) a mating between two individuals hterozygous for the trait of interest
E) None of the choices are correct.
Provide the correct answer and justification for your choice.