Final answer:
Punnett squares are most accurately described as tools used to predict all possible allele combinations and their frequencies in offspring by using the principles of probability applied to genetic crosses.
Therefore, option A is corrrect
Step-by-step explanation:
The statement that best describes why Punnett squares are useful is:
A. Punnett squares are used to predict all possible allele combinations and their frequencies in offspring.
Punnett squares, conceived by the British geneticist Reginald Punnett, are tools that utilize the principles of probability and meiosis to predict how genes will interact in the progeny. They are drawn to represent all potential outcomes of genetic crosses, showing the combination of alleles that come together in fertilization. By listing one parent's alleles across the top and the other's down the side of the square, they visualize the resulting genotypic ratios of zygotes as a product of random gamete combination. In cases such as a monohybrid cross with true-breeding parents, a Punnett square exhibits that each parent will contribute a single allele type, leading to specific genotypic and, following Mendelian inheritance patterns, phenotypic outcomes. These tools are not only limited to predicting traits in pea plants but apply to many genetic contexts, including human genetic disorders.