Final answer:
Using a Punnett square, we can find that the probability of obtaining an offspring with the genotype bb from two Bb parents is 25%.
Step-by-step explanation:
The question involves predicting the genotype of offspring from a genetic cross, which is a key concept in Mendelian genetics. When crossing two individuals with the genotype Bb, we are dealing with a monohybrid cross where both parents are heterozygous for a single gene.
A Punnett square is a graphical way to predict all possible genotypes of offspring from parents with known genotypes. In this case, each parent has a 1 in 2 chance of passing on either allele B or b.
To calculate the probability of obtaining bb offspring, multiply the probability of one parent passing on b (1/2) by the probability of the other parent also passing on b (1/2), which equals 1/4 or 25%. Therefore, the probability of an offspring having the genotype bb is 25%.