Final answer:
A 1 base substitution mutation occurs when a single base nucleotide in DNA is replaced by another nucleotide, potentially impacting the function of the protein.
Step-by-step explanation:
A 1 base substitution mutation is a type of mutation that occurs when a single base nucleotide in DNA is replaced by another nucleotide. This can result in changes to the amino acid sequence during protein synthesis, potentially impacting the function of the protein.
For example, if a DNA sequence contains the base adenine (A) and it is substituted with guanine (G), this is a 1 base substitution mutation.