Which mutation occurs when one nucleotide base is replaced with another base

The correct answer is a substitution mutation.  

A mutation, which substitute’s one base for another, that is, a change in a solitary chemical letter like switching an A to a G is known as a substitution mutation. This kind of substitution can modify a codon to something, which encrypts a distinct amino acid and leads to a small modification in the generated protein.  

the "dirty dozen" chemicals banned in an international treaty are formally known as persistent organic pollutants, or pops. the united nations environment program provided this background on what they are and what they can do to humans and wildlife.

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