What is the purpose of a test cross?

A test cross is a genetic breeding method used specifically to determine the genotype of an individual that exhibits a dominant phenotype. More specifically, it assesses whether this individual is homozygous (having two identical alleles for a trait) or heterozygous (having two different alleles for a trait). This is accomplished by crossing the individual in question with another individual that is homozygous recessive for the trait being studied.

When the offspring are analyzed, if any of the offspring express the recessive phenotype, it indicates that the tested individual is heterozygous because it has contributed a recessive allele. Conversely, if all the offspring exhibit the dominant phenotype, it suggests that the individual is homozygous. This method is fundamental in genetics as it helps to reveal the genetic composition behind observable traits.

The other choices present different concepts that do not align with the primary objective of a test cross. While producing offspring is certainly a result of any cross, it is the information gained about the genotype that is crucial. Observing dominant traits and identifying male and female offspring are outcomes of breeding experiments but do not specifically pertain to the purpose of conducting a test cross.