Final answer:
A Punnett square shows all of the possible outcomes of a genetic cross, including the potential genotypes and phenotypes of offspring, by combining the alleles of two parents in a grid.
Step-by-step explanation:
The answer to the question is (d) all of the possible outcomes of a genetic cross. A Punnett square is a tool developed by British geneticist Reginald Punnett to visualize the possible genotypes of offspring from a genetic cross. It utilizes a grid to combine the possible gametes of two parents to predict the potential genetic makeup and therefore possible phenotypes of their offspring. The alleles from one parent are listed across the top, and those from the other parent are listed down the side. The inside of the grid shows all the possible combinations when these alleles merge, representing the genotypic ratios and, if the dominant and recessive traits are known, the phenotypic ratios as well. This can be exemplified through a monohybrid cross, such as crossing pea plants with yellow seeds (YY) and green seeds (yy), where the offspring would all have yellow seeds (Yy) due to the dominance of the yellow seed trait.