Question

What is the mutation caused by the addition of a nucleotide to an already existing gene sequence called?
A.
deletion
B.
duplication
C.
insertion
D.
inversion

Answer 1

A deletion mutation occurs when part of a DNA molecule is not copied during DNA replication. This uncopied part can be as small as a single nucleotide or as much as an entire chromosome. The loss of this DNA during replication can lead to a genetic disease.

Duplication is a type of mutation that involves the production of one or more copies of a gene or region of a chromosome. Gene and chromosome duplications occur in all organisms, though they are especially prominent among plants. Gene duplication is an important mechanism by which evolution occurs.


In genetics, an insertion (also called an insertion mutation) is the addition of one or more nucleotide base pairs into a DNA sequence. This can often happen in microsatellite regions due to the DNA polymerase slipping.

An inversion is a chromosome rearrangement in which a segment of a chromosome is reversed end to end. An inversion occurs when a single chromosome undergoes breakage and rearrangement within itself.