Definition for Deletion
From Biology Forums Dictionary
1) A missing region of a chromosome.
2) In genetics, a deletion is a mutation (a genetic aberration) in which a part of a chromosome or a sequence of DNA is missing. Deletion is the loss of genetic material. Any number of nucleotides can be deleted, from a single base to an entire piece of chromosome. Deletions can be caused by errors in chromosomal crossover during meiosis. This causes several serious genetic diseases. Deletion also causes frameshift.