In
biology, a mutation is an alteration in the
nucleic acid sequence
A nucleic acid sequence is a succession of Nucleobase, bases signified by a series of a set of five different letters that indicate the order of nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. By convention, sequence ...
of the
genome of an
organism,
virus, or
extrachromosomal DNA
Extrachromosomal DNA (abbreviated ecDNA) is any DNA that is found off the chromosomes, either inside or outside the nucleus of a cell. Most DNA in an individual genome is found in chromosomes contained in the nucleus. Multiple forms of extrachromo ...
. Viral genomes contain either
DNA or
RNA
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...
. Mutations result from errors during
DNA or
viral replication,
mitosis
In cell biology, mitosis () is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis gives rise to genetically identical cells in which the total number of chromosomes is mainta ...
, or
meiosis or other types of
damage to DNA (such as
pyrimidine dimers caused by exposure to
ultraviolet radiation), which then may undergo error-prone repair (especially
microhomology-mediated end joining), cause an error during other forms of repair,
or cause an error during replication (
translesion synthesis). Mutations may also result from
insertion
Insertion may refer to:
*Insertion (anatomy), the point of a tendon or ligament onto the skeleton or other part of the body
*Insertion (genetics), the addition of DNA into a genetic sequence
*Insertion, several meanings in medicine, see ICD-10-PCS
...
or