The following points highlight the three types of point mutation. The types are: 1. Non-Sense Mutations 2. Missense Mutation 3. Silent Mutation. Type # 1. Non-Sense Mutations: Non-sense mutation is one type of point mutation. There are 64 codons that code for amino acid out of which three codons (UAA, UAG, UGA) are known as termination codons that do not [...]
In this article we will discuss about the chemical and physical types of mutagens. 1. Chemical Mutagens: Singer and Kusmierek (1982) have published an excellent review on chemical mutagenesis. Some of the chemical mutagens and mutagenesis are given in Table 9.3, and described below: i. Base Analogues: A base analogue is a chemical compound similar to one of the four [...]
In this article we will discuss about:- 1. Origin of Spontaneous Mutations 2. Evidence for Spontaneous Mutation 3. Random Nature 4. Mutation Rates. Origin of Spontaneous Mutations: Mutation involves changes in DNA. Several mechanisms are known that bring about alterations in DNA. These modifications may arise from error in DNA replication, damage to DNA from radiation. Errors occur during replication [...]