Gene Interaction - The elegance of Mendel's experiments was partly due to the complete consistency between his observations and the hypothesis he developed.

Mendel was lucky that in his studies the characteristics he chose were governed by a single gene. However after Mendel's work was rediscovered, it became clear that simple Mendelian model is not sufficient to predict experimental observations in all situations.

Two or more genes govern the expression of many characters in almost all organisms. These genes affect the development of the concerned characters in various ways.The phenomena of two or more genes governing the development of a single character in such a way that they affect the expressions of each other in various ways is known as gene interaction.