<unk> on a chromosome In genetics, a<unk> (also called gene<unk>  deficiency, or<unk> mutation) (sign: Δ) is a mutation (a genetic aberration) in which a part of a chromosome or a sequence of DNA is left out during DNA replication. Any number of nucleotides can be deleted, from a single base to an entire piece of chromosome. The smallest single base<unk> mutations occur by a single base flipping in the template DNA, followed by template DNA strand slippage, within the DNA polymerase active site.<unk>  can be caused by errors in chromosomal crossover during meiosis, which causes several serious genetic diseases.<unk>  that do not occur in multiples of three bases can cause a frameshift by changing the 3-nucleotide protein reading frame of the genetic sequence.<unk>  are representative of eukaryotic organisms, including humans and not in prokaryotic organisms, such as bacteria.
Deletion 
Flagging 
Mutation
Efference copy
Aplasia
Honeycombing
Exon shuffling
ConFusion