Question

What is point mutation?

Answer 1

Hint: Mutations are the errors made during cell division, exposure to ionizing radiation, exposure to chemicals called mutagens, or infection by viruses may result in mutations. A point mutation is a form of mutation that causes the genetic material, DNA or RNA, to substitute a single base nucleotide.

Complete Answer:
The mutation in the single nucleotide base of the DNA segment is called a point mutation. It may insert a premature stop codon, or a nonsense codon, into the transcribed mRNA (nonsense mutation) by addition or deletion of the base, or alter a codon specifying a different amino acid by replacing a single base amino acid (missense mutation).

For example, the substitution of A by T in the 17th nucleotide of the Hbb gene changes the codon GAG (glutamic acid) to GTG (which encodes valine) and causes sickle cell anemia.

There are two forms of point mutations: transition mutations and transformation mutations. Transitional mutations occur when the base of pyrimidine (e.g. thymine [T] or cytosine [C]) replaces another base of pyrimidine or when a purine foundation (e.g. adenine [A or guanine [G]) replaces a second basis of purine.

Additional information:
Some of the mutations have been found to have a beneficial effect and are called beneficial mutations. These mutations are responsible for contributing new versions of proteins which help the species to adapt and survive in the changing changes. Beneficial mutations are important for the purpose of evolution to occur.

Note: In one set of methods, mutations are analyzed after PCR amplification of the target sequence. The base substitutions are identified by various techniques called allele-specific hybridization and restriction digestion. PCR is part of the detection scheme and is an alternative collection of methods.