Final answer:
The assertion that a Punnett square does not show the law of segregation is false. Both the law of segregation and the law of independent assortment can be demonstrated using Punnett squares, for monohybrid and dihybrid crosses respectively.
Step-by-step explanation:
The statement is false. A Punnett square does, in fact, show the law of segregation as well as the law of independent assortment. The law of segregation states that allele pairs separate or segregate during gamete formation, and randomly unite at fertilization. A monohybrid cross, which tracks one gene, can be represented in a simple 2x2 Punnett square and demonstrates how alleles segregate into the gametes. This square predicts the genotype of offspring with respect to one particular gene. On the other hand, a Punnett square can also demonstrate the law of independent assortment through a dihybrid cross, which tracks the inheritance of two different genes. In this larger 4x4 square, the assortment of alleles for the two different genes into gametes is shown to be independent of each other. Both genetic principles are foundational to understanding Mendelian genetics and can be predicted with a Punnett square.