In a particular population, over the course of several dozen generations, an adenine was replaced by a guanine at a particular non-coding locus in the dna base sequence. the evolutionary mechanism responsible for this change was?

Mutation

Explanation:

A Mutation alters the genetic message carried by that gene as there are permanent changes in the nucleotide sequence of DNA or a DNA gene.

This can occur by base pairs substitution, deletion or insertion

d. organisms have cells with different shapes and functions.

answer; synapse; i believe this is correct,plz check first good luck;