Question

We can find out whether an organism is homozygous or heterozygous for a trait by carrying out a ______.

Answer 1

We can find out whether an organism is homozygous or heterozygous for a trait by carrying out a test cross.

Explanation:

A test cross is performed by crossing an individual showing the dominant phenotype (but unknown genotype) with a homozygous recessive individual. If any offspring show the recessive phenotype, this indicates that the tested organism is heterozygous. If all offspring show the dominant phenotype, the organism is homozygous dominant. Thus, a test cross helps determine the genotype of an organism with a dominant trait by analyzing the phenotypes of its offspring.