What is the primary function of a Punnett square?

The primary function of a Punnett square is to determine the probability of expressed phenotypes in offspring resulting from a cross between two parents. It achieves this by providing a visual representation of how alleles from each parent can combine. By outlining the possible combinations of alleles in a grid format, educators and geneticists can easily see the potential genotypes and phenotypes that might result from a particular genetic cross.

For example, if one parent is homozygous dominant for a trait (AA) and the other is homozygous recessive (aa), the Punnett square clearly shows that all offspring will inherit the dominant allele from the first parent and the recessive allele from the second, leading to a genotype of Aa. Consequently, understanding this outcome allows one to predict that all offspring will display the dominant phenotype, thereby demonstrating the Punnett square's utility in visualizing genetic inheritance.

Other choices may touch on aspects of genetics, but they do not focus on the primary function of a Punnett square, which is specifically to illustrate the inheritance patterns of traits and the likelihood of specific phenotype expressions in the offspring.