Question

Assess the biological impact of a single base substitution in a codon?

Answer 1

Single base substitutions(transition or transversion) can have a variety of biological effects. The silent mutation is an example of a base substitution, where the change in nucleotide base has no outward effect. A missense mutation refers to a base substitution when the change in nucleotide changes the amino acid coded for by the affected codon. A nonsense mutation refers to a base substitution in which the changed nucleotide transforms the codon into a stop codon. Such a change leads to a premature termination of translation, which can badly affect the formation of proteins and disturb cell metabolic process or change phenotypes in organism.