Question

how the point mutation occur

Answer 1

A point mutation occurs in one nucleotide molecule in its triplet codon of 3 nucletides. One of the base pairs is change. For example adenine could become thymadine. This would result in a change of one codon. which if not corrected would change the paticular amino acid of the codon and could affect the protein that the amino acid is a part of. For example a codon coding for a particular amino acid could chacnge to a stop codon and chop off (truncate), the protein at that point resulting in a shortened useless protein.Such mutations cause certain types of mucular dystrophy etc. Point mutations are a sources of genetic change. and a minority of those chacnges are positive althogh most are neutral ir deleterious. Cosmic rays can cause point mutations. Also carcinogenic chemicals, old age ionising radiation and certain chemicals. (e.g. 5 fluoro uracil etc.)