In what way could mutations contribute to the number of bases in a gene?

Mutations can indeed increase the number of bases in a gene by introducing additional nucleotides into the genetic sequence. This can occur in various ways, such as through insertion mutations, where one or more base pairs are added into the DNA strand. When this happens, the overall length of the gene increases, and potentially, its function can also be altered, leading to changes in the resulting polypeptide.

In this context, mutations can play a significant role in genetic diversity and evolution, as they can result in new traits or functions that may be beneficial or detrimental to an organism. The alteration in the gene sequence due to these mutations can also have implications for protein synthesis, as the added bases may affect the reading frame or introduce premature stop codons.

Other options suggest scenarios that don't accurately represent how mutations generally function or their impact on gene structure. For example, they do not account for the variability and potential complexity of mutation effects on a gene's nucleotide sequence.