Genes have several crucial functions.

• Carry hereditary information from one generation to another
• Control the functions of DNA and RNA
• Control the morphology or phenotype of individuals
• Play a role in protein synthesis
• Facilitate cell division 
• Control the development of different stages in the life history of the organism
• Regulate the organism’s structure and metabolism
• Generate variations by reshuffling at the time of sexual reproduction
• Change expression by undergoing mutation
• Cross over to produce different linkages