Final answer:
When two heterozygous individuals are crossed, such as Bb x Bb for a trait where 'B' is dominant, the genotypic ratio in the offspring is expected to be 1 BB : 2 Bb : 1 bb, and the phenotypic ratio is typically 3:1, favoring the dominant trait. A Punnett square is a common tool used to predict these outcomes.
Step-by-step explanation:
Understanding Genotypic and Phenotypic Ratios
When examining the concepts of genetics, it's important to identify genotypic ratios and phenotypic ratios resulting from various crosses between organisms. When two heterozygous (Aa) individuals are crossed, the genotypic ratio for their offspring is typically 1 AA : 2 Aa : 1 aa, and the phenotypic ratio is 3:1, with the dominant trait being observed in a higher proportion of the offspring.
For example, a cross between two pea plants that are heterozygous for flower color (Bb x Bb) will result in approximately 75% of the offspring exhibiting the dominant phenotype.
The Punnett square is a useful tool for predicting these ratios. It presents a visual representation of the possible genotypes of the offspring and their corresponding phenotypes. Using this method, you can see that the genotypic ratio from a Bb x Bb cross is 1 BB : 2 Bb : 1 bb, while the phenotypic ratio is 3 (with the dominant trait) to 1 (with the recessive trait).