Final answer:
A Punnett square is a chart that helps determine the expected genotypes in the offspring of two parents. In the example given, the Punnett square shows that the offspring will have a genotypic ratio of 1 BB: 1 bb: 2 Bb.
Step-by-step explanation:
A Punnett square is a chart that allows you to easily determine the expected percentage of different genotypes in the offspring of two parents. In the example given, both parents are heterozygous for flower color (Bb). The different possible combinations of alleles in their offspring are determined by filling in the cells of the Punnett square. In this case, one out of four offspring will have the genotype BB, one out of four will have the genotype bb, and two out of four will have the genotype Bb.