Consider a true-breeding plant, AABBCC, crossed with another true-breeding plant, aabbcc, whose resulting offspring are AaBbCc. If you cross the F₁ generation, and independent assortment is operational, the expected fraction of offspring in each phenotypic class is given by the expression N!/M!(N−M)! where N is the total number of alleles (six in this example) and M is the number of uppercase alleles. In a cross of AaBbCc×AaBbCc, what proportion of the offspring would be expected to contain two uppercase alleles?

Key Concepts

Mendelian Genetics

Mendelian genetics is the study of how traits are inherited through generations based on the principles established by Gregor Mendel. It includes concepts such as dominant and recessive alleles, genotype, and phenotype. In this context, understanding how alleles segregate and assort independently during gamete formation is crucial for predicting offspring traits.

Independent Assortment

Independent assortment is a principle stating that alleles for different traits segregate independently of one another during gamete formation. This means that the inheritance of one trait does not affect the inheritance of another. In the given question, this principle allows us to calculate the expected proportions of offspring phenotypes when crossing two heterozygous plants.

Binomial Probability

Binomial probability is a statistical method used to determine the likelihood of a certain number of successes in a fixed number of trials, given a constant probability of success. In the context of the genetic cross, it helps calculate the expected proportion of offspring with specific combinations of alleles, such as two uppercase alleles, by applying the binomial formula to the outcomes of the cross.