An offspring receives a set of chromosomes from each parent's gamete. Both sets of chromosomes contain genes for each trait of that offspring, and it is the properties of those genes that determine what variation of that trait is exhibited. Mendel found that some forms of a given trait are dominant over others, and we know today that this is because some alleles of a given type of gene are dominant while others are recessive. In the case of some dominant traits, like polydactylism, the prevalence of that trait in a given population may be so low that it appears recessive. Mendel's experiments led the way for the field of genetics, where scientists study heredity and variation in genes and how they are expressed.

• When you have completed this lesson, you should be able to:
• describe the patterns of inheritance that Mendel's data revealed summarize Mendel's law of segregation explain how there can be many variations of one gene