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.
Inversion mutations occur when a section of DNA breaks away from a chromosome during the reproductive process and then reattaches to the chromosome in reversed order.
Translocation is a type of chromosomal abnormality in which a chromosome breaks and a portion of it reattaches to a different chromosome.