Modern concept of gene

Genes are units of inheritance.

A gene is a segment of DNA that provides instructions for synthesis of a specific protein or a particular type of RNA.

It may be defined as a segment of DNA which is responsible for inheritance and expression of a particular character.

 

Cistron, Muton and Recon.

Seymour Benzer (1955), introduced the terms: cistron, muton and recon

Cistron (Unit of function)

It is a segment of DNA having information for synthesis of a particular protein or RNA. It can be several hundred bp (base pairs) long.

It is responsible for expression of a trait.

 

Muton (Unit of mutation)

It consists of a few nucleotides, (one to few bp long.)

It is segment of DNA that can undergo mutation.

 

Recon (Unit of recombination)

It is segment of DNA that participates in recombination through crossing over during meiosis. It consists of few to many base pairs.