THE CHI-SQUARE TEST Probability, Random Chance, and Genetics

Probability, Random Chance, and Genetics Why do we study random chance and probability during a unit on genetics? Genetics is the study of inheritance, but it is also a study of probability. Most eukaryotic organisms are diploid, meaning that each cell contains two copies of every chromosome, so there are two copies of each gene that controls a trait (alleles). In sexual reproduction, these two copies of each chromosome separate, and are randomly sorted into the reproductive cells (gametes). When gametes from two different parents combine in fertilization, new combinations of alleles are created. Thus chance plays a major role in determining which alleles, and therefore which combinations of traits end up in each new individual. The important point is that the inheritance of characteristics is the result of random chance. Therefore, it is important to understand the nature of chance and probability and the resulting implications for the science of genetics. In short, the genes that an individual organism inherits depends on the “luck of the draw,” and the luck of the draw is dependent on the laws of probability.