The answer to the question stated above is Duplication.
Duplication is one of the chromosomal mutation whereby a segment of chromosome is copied twice, resulting in extra allele.
Chromosomal mutation involves the change in chromosome structure which changes the composition or location allele.
Other chromosomal mutation includes:
Deletion - occurs when a segment of chromosome is broken off and lost.
Inversion - happens when a segment of chromosome is broken off and reattach itself in inverted position.
Translocation - takes place when a segment of chromosome is broken off and reattach at different point.
