BioCoach Activity

Concept 1: Reviewing Mendel's Laws

An analysis of genetic crosses depends upon an understanding of Mendel's two laws:

In practice, the manifestation of Mendel's laws is seen by characteristic ratios of phenotypic classes, such as 3:1 and 9:3:3:1. Further, the Mendelian principles just stated include the simple assumption that one allele is dominant to the other allele.

In the time since Mendel's original experiments, we have come to learn that there are extensions to Mendelian principles, including the fact that some alleles are incompletely dominant, that some genes are sex-linked, and that some pairs of genes do not assort independently because they are physically linked on a chromosome.