When there is a mutation in the DNA nucleotide sequence where GGC passes into GGA, the mutation is a point mutation of the silent type.
Explanation:
A point mutation of DNA, where the cytosine nucleotide is changed to adenine, GGC to GGA, the resulting triplet mRNA is CCU, instead of GCC.
Codons CCG and CCU encode the same amino acid, which is proline (Pro), so despite the existence of a mutation, the protein that is synthesized will not have alterations in its number or sequence of amino acids.
Silent mutations are characterized by changes in a nucleotide in the DNA base sequence that do not affect changes in the coding protein, as happens in the change of GGC to GGA.