Gene:

Definition:
The fundamental unit of heredity, formed as a sequence of bases in DNA.

Characteristics Of Genes:
• Each gene has a definite position at the chromosome and may occur as alleles.
• The name gene was introduced by Johannsen in 1909 and the structure of DNA was elaborated by Watson and Crick in 1953.
• Genes determine all the structural and functional characters of an individual, like eye colour, skin colour, height, weight, blood group, hair, intelligence, temperament and all others.
• The characters from one generation to other are taken by genes.
• They sometimes change through the process of mutation. This gives variety in characters.
• The accurate structure of the proteins and enzymes in the body is determined by genes.