Final answer:
An insertion or deletion of a single nucleotide is likely to cause a frameshift mutation, significantly altering the resulting protein by changing the reading frame in which codons are read. Missense mutations, which are a type of point mutation, lead to a change in a single amino acid and can vary in their impact on protein function.
Step-by-step explanation:
A frameshift mutation is likely to be caused by an insertion or deletion of a single nucleotide. Unlike a transversion or a transition, which are types of substitutions that replace one nucleotide for another, an insertion adds an extra nucleotide into the DNA sequence. This addition can change the way the sequence is read in groups of three nucleotides, called codons, thereby altering the resulting amino acid sequence drastically.
Insertions or deletions that are not in multiples of three nucleotides cause the reading frame to shift. As a result, this changes the grouping of the codons and can potentially change every subsequent amino acid in the protein sequence. It can also result in the creation of a premature stop codon, terminating translation prematurely. Frameshift mutations are more consequential early in the sequence and can result in a completely nonfunctional protein.
A missense mutation is a point mutation where a single nucleotide change results in a codon that codes for a different amino acid. This can have varying effects on the protein function, depending on the importance and position of the amino acid. Missense mutations are a contrast to silent mutations, which do not affect the amino acid sequence due to the redundancy in the genetic code.