Question

In a beetle, a substitution point mutation occurs in a DNA segment between two genes. One of the genes controls antennae length, with more expression leading to longer antennae. The other gene controls body color, with more expression leading to darker color. What is the most likely effect of this mutation?

Answer 1

Substitution point mutations are silent mutations and does not cause any significant change in the protein or the phenotype.

Explanation:

A substitution point mutation is a silent mutation resulting from base substitution (one base is substituted for another base on a codon in a DNA sequence) occurring only between two gene points.

The amino acids coding for a protein are formed by codons or the bases grouped together.

When only a single base is substituted, the resulting protein formed will not change since the substitution causes only very mild undetectable changes which cannot bring about strong mutation to change the nature of a protein.

Proteins formed are responsible for the various characters or phenotypes formed in an organism. Hence, the phenotypes of the beetle like the antennae length or the dark color also do not change due to substitution point mutations.