Gregor Mendel is known as the father of genetics since he first worked on the inheritance studies in the pea plant. He is also the founder of modern genetics. He deeply got involved in studying the hereditary patterns in the Pisum sativum plant and discovered various traits. We need to understand certain basic concepts before proceeding with Mendel's scientific work. The characteristics of an individual get transmitted from generation to generation. These characteristics are known as hereditary traits. These traits come under the influence of genes. Before knowing the word gene, Mendel used the word factors. Hence the genes or the factors determine the expression of the trait. The observable characteristic or the trait is known as the phenotype. The genetic constitution is also known as the genotype. The expression of a phenotypic trait not only depends on the genotype of the individual but also depends on the actions of the other genes or their products accompanied by the influence of the environmental factors.