DNA is a long double-strand of molecules, called nucleotides, that code for specific proteins in a cell. The code of DNA can be disturbed by environmental factors. A gene mutation is a sequence of DNA that has been damaged.
A deletion occurs when one or more nucleotides is removed from a string of DNA.
An insertion occurs when extra nucleotides are added to a string of DNA.
Because the exact sequence of nucleotides in a strand of DNA are required to code for specific proteins, a deletion disrupts the ability for proteins to be synthesized. Mutated DNA is unable to code for the correct proteins.
