The word 'heredity' is simply the name given to the means by which living organisms reproduce their kind. It is understood merely as reproduction of like by like. It is an operation of the passing of characteristics from parents to off-spring. All living things human beings, plants and animals-pass on their traits from one generation to other generation Men have always known that wheat grows from wheat seed and millet from millet seed. Although the terms heredity has vast connotation and covers all living organism including animals and plants, but more emphasis will be on human beings and animals. This will include the process of reproduction-chemical transformation and physical forces that provide for continuation of life; and what factors contribute to the resemblance of off-springs to their parents.