What is the outcome of a nonsense mutation?

A nonsense mutation occurs when a single nucleotide change in the DNA sequence results in the formation of a premature stop codon. This premature stop codon signals the translation machinery to end protein synthesis earlier than it normally would, leading to a truncated protein. The truncated protein is typically shorter than the full-length functional protein and may lack important functional domains, which often results in a loss of function.

This is why the outcome of a nonsense mutation is significant; the protein produced is not complete and can be nonfunctional or have drastically altered functionality compared to the intended protein. The other choices do not accurately describe the effects of a nonsense mutation. For example, if a mutation produced a functional protein, that would suggest the change did not disrupt the coding sequence, which is not the case here. Similarly, if it had no effect on protein synthesis or only changed one amino acid, those would not align with the characteristics of a nonsense mutation that leads to early termination of the protein coding sequence.