Question

explain the various types of mutagens with the help of example?

Answer 1

Agents which bring about mutations are known as mutagens. Nitrogenous bases in DNA are changed due to physical mutagens like radiations i.e. X-rays, UV rays, and gamma rays and some chemical mutagens. By chemical mutations following changes are expected:-

1. Deamination of bases:- chemicals like nitrous oxide deaminate from nitrogenous bases and therefore change codon.
2. Incorporation of base analogue:- 2 common base analogues are 5-Bromouracil (5 BU) and 5 Fluorouracil (5 FU). Both are analogous bases to thymine in DNA.
3. Methylating agents:- Nitrogen mustard cause addition of methyl group to the nitrogenous bases of DNA.
4. Acridine dyes:- Acridine orange and proflavin dyes causes insertion or deletion of nitrogenous bases in a gene and may lead to frame shift type of mutations.