mutations

• a mutation is a random change in an organism's DNA
• the chance of a genetic mutation happening is increased by exposure to certain substances or some types of radiation
• mutations change the sequence of the DNA bases in a gene, producing a genetic variant
• as the sequence of DNA bases codes for the sequence of amino acids that make up a protein, mutations to a gene sometime lead to changes in the protein that it codes for
• most mutations have very little or no effect on a protein. some will change it to a very small extent
• in some cases, mutations can seriously affect a protein, causing it to no longer function properly
• if there's a mutation in non-coding DNA, it can alter how genes are expressed
• there are three main types of mutations that can occur in a gene: insertions ; deletions and substitutions
• insertions are where a new base is inserted into the DNA base sequence where it shouldn't be
• insertions can change more than one amino acid as they have a knock-on effect on the bases further on in the sequence
• deletions are when a random base is deleted from the DNA base sequence
• substitution mutations are when a random base in the DNA base sequence is changed to a different base