Which trait's probability can be determined using a Punnett square?

A Punnett square is a predictive tool used in genetics to determine the probability of specific traits being inherited from one generation to the next. When considering traits, the Punnett square allows one to visualize the potential combinations of alleles from the parent organisms.

In the context of the correct answer, the likelihood of specific alleles appearing in offspring is assessed by inputting the genotypes of the parents into the Punnett square. Each cell in the square represents a possible genotype of the offspring, allowing for a clear understanding of the ratio of different allele combinations. This is particularly useful in studying traits governed by Mendelian inheritance patterns, such as dominant and recessive traits.

The other options do not pertain directly to the function of a Punnett square. The exact number of offspring produced is not something that can be predicted solely by the genotypes of the parents and may depend on various biological and environmental factors. Similarly, the lifespan of the offspring and the health of the parents are influenced by a range of genetic and environmental variables, and while they may relate to genetic factors, they cannot be determined simply through a Punnett square analysis. Thus, the focus of the Punnett square remains on the probabilities of allele inheritance.