point mutations vs insertion mutations

[mango10]

Can anyone help me with this:


threonine (amino acid) : ACU, ACC, ACA, ACG implies that point mutations at the third postion will have no effect right? or is it insertion mutation?
can anyone confirm this? thank you :]

[Yggdrasil]

A point mutation at the third position will be a silent mutation.  Insertion mutations are different than point mutations.  Point mutations refer to nucleotide substitutions, while insertions refer to an extra nucleotide insterted into a sequence.