A Punnett square is a diagram that is used to predict the genotype and phenotype combinations of offspring from parental alleles. When dealing with a dihybrid cross, which involves two traits, the dimensions of the Punnett square are determined by the number of possible allele combinations for each parent.
In a dihybrid cross, each parent has two alleles for each of the two traits. This means each parent can produce 4 different combinations of alleles (2 alleles for the first trait × 2 alleles for the second trait). Therefore, the Punnett square for a dihybrid cross will have 4 rows and 4 columns, resulting in a 4 × 4 grid.
So, the correct answer is:
c) 4 × 4
This 4 × 4 Punnett square allows for the visualization of all 16 possible genotype combinations that can result from the cross of two heterozygous parents for two traits.