In this article we will discuss about the discovery and evolution of split genes. Discovery of Split Genes: During 1970, in some mammalian viruses (e.g. adenoviruses) it was found that the DNA sequences coding for a polypeptide were not present continuously but were split into several pieces. Therefore, these genes were variously named as split genes or introns, interrupted genes [...]
In this article we will discuss about the concept and units of genes. Concept of Gene: Although the role of hereditary units (factors) in transfer of genetic characters over several generations in organisms was advocated by Gregor John Mendel, yet the mystery of the 'hereditary units' was un-ravelled during early 1900s. In 1909, W. Johanson coined the term 'gene' that [...]
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 [...]