mutations

• a mutation is a change in the DNA sequence that happens spontaneously when DNA is replicated.
• certain types of radiation or carcinogens (harmful chemicals) increase the risk of mutations
• a mutation can change the complimentary amino acid in a gene, which can lead to a change in the protein produced - potentially meaning its no longer fit for its function.
• most of the time mutations have no effect on the organism as most of them occur in non-coding DNA
• substitution mutations are when one of the bases in a DNA sequence is replaced by another
• an insertion mutation is when an extra base is inserted into the DNA sequence. This is worse than substitution mutations as it can cause a frameshift, and lots of codons are changed.
• deletion mutations are when one of the bases are deleted from the gene meaning all lots of codons are shifted back.