Final answer:
A frameshift mutation could be an insertion or deletion in a gene sequence that changes the reading frame, altering the subsequent amino acids coded. Frameshift mutations are unlikely to be silent because they change codon groupings, often resulting in a drastically different and usually nonfunctional protein.
Step-by-step explanation:
Examples of Frameshift Mutations and Their Consequences
a) An example of a frameshift mutation on the gene with the base sequence CGTAT would be the insertion of a base, such as an A, resulting in the sequence CGTAAT. Alternatively, a deletion, such as removing the G, would result in the sequence CTAT. Both of these would cause a shift in the reading frame, altering the entire sequence of coded amino acids beyond the point of mutation.
b) It is very unlikely for a frameshift mutation to be a silent mutation because frameshifts usually result in a complete change of the amino acid sequence. Since the nucleotide bases are read in groups of three (codons) during translation, the insertion or deletion of a base changes the grouping of the bases and thus changes the codons that are read afterward. This typically alters the resulting amino acids and can introduce premature stop codons, leading to a nonfunctional protein or truncated protein that usually differs from the original protein's function significantly.