Which statement is true about Punnett squares?

• A. They predict possible genetic outcomes of a cross
• B. They show the exact maturation of an offspring
• C. They determine the age of a fossil
• D. They map the genome sequence

Answer: (A)

Punnett squares organize the alleles from each parent to predict the possible genetic outcomes of a cross. By laying out all possible gamete combinations, each box shows a potential offspring genotype, and counting how often each genotype appears gives the chances or probabilities of those outcomes. This is useful for understanding inheritance patterns and what traits might appear in offspring, but it doesn’t guarantee what will happen in any single birth.

It doesn’t tell us how an organism will mature, since development timing is influenced by many genes and environmental factors. It isn’t used to determine the age of fossils, which is done through dating methods like radiometric dating and stratigraphy. And it isn’t a way to map an entire genome sequence, which requires DNA sequencing and assembly rather than cross-breeding patterns.