ABSTRACT
Mutation is any heritable change in the genetic material which is transmitted to daughter cells and even to succeeding generations giving rise to mutant cells or mutant individuals. Chromosome mutations are structural changes of the particular chromosomes with gain, loss, or translocation of chromosome fragments. Chromosome mutations are either intrachromosomal or interchromosomal. The mutation rate depends on mutability of the particular gene, and the ability of mutation repair. The molecular mechanisms of mutations depend mainly on the intrinsic properties of nucleic acids. Mutations of the genetic code also may be caused by different irradiations. The most widespread mutagens are ionizing radiation, ultraviolet rays, base analogs and alkylating agents. Alkylating agents includes monofunctional alkylating agents, bisulfite, hydroxylamine and methoxyamine, hydrazine, formaldehyde, bifunctional alkylating agents, mustards, lactones, epoxides, vinyl halides, and alkyl carbamates. Naturally Occurring Mutagens are aflatoxins, and sterigmatocystin. The deoxyribonucleic acid (DNA) repair mechanisms include: photoenzymatic DNA repair, an excision repair mechanism and postreplicative mechanism.
