What kind of mutation is this ugu-ccg-GAA-cga to ugc-cgg-GAA-cga?

The sequence TGA-GCC-ATG-A is changed in 2 places to become TGA-GCA-CAT-GA.

When one base is changed, it is called a point mutation.

In this case, a GCC in the DNA has been changed to a GCA. This would mean the mRNA codon (coded for by this DNA) would change from CGG to CGU.

Both of these codons code for the same amino acid - Arginine. Therefore this type of point mutation is known as a silent mutation.

The extra C that appears would be called an addition mutation, which is a type of frameshift mutation.