To dissect genetic processes or create organisms with novel suites of traits, scientists can perform genetic crosses, or the purposeful mating of two organisms. The recombination of parental genetic material in the offspring allows researchers to deduce the functions, interactions, and locations of genes.

This video will examine how genetic crosses were influential in developing Mendel's three laws of inheritance, which form the basis of our understanding of genetics. One genetic crossing technique that was first developed for single-celled organisms such as yeast, known as tetrad analysis, will then be presented in detail, followed by some examples of how this classical tool is used in genetic studies today.