Question

When a mutation is limited to the substitution of one nucleotide pair for another, it is called a ______.

Options

• point mutation

• base inversion

• translocation

• sugar-phosphate deletion

Answer 1

When a mutation is limited to the substitution of one nucleotide pair for another, it is called a point mutation.

Explanation:

A point mutation refers to a gene mutation where a single nucleotide pair in the DNA sequence is substituted by another nucleotide pair. This substitution alters the base sequence at one fixed point on a chromosome without affecting the rest of the sequence. Other types of mutations include insertion, deletion, inversion, or translocation, which involve larger-scale changes in the DNA or chromosome structure. Point mutations specifically involve the replacement of one nucleotide pair with another, commonly seen in genetic disorders such as sickle cell anemia where a single base substitution causes an amino acid change in hemoglobin.