Final answer:
A base substitution in DNA that leads to a change in the amino acid sequence is termed a missense mutation. This is different from a silent mutation, which causes no change, a nonsense mutation.option c is correct answer.
Step-by-step explanation:
Understanding Mutations in DNA
A base substitution in DNA that ultimately leads to a change in the encoded amino acid is called a missense mutation. This type of mutation results when a single nucleotide change alters the codon so that it encodes a different amino acid. One classic example of a missense mutation is sickle cell disease, where a substitution leads to the amino acid valine replacing glutamic acid, causing the hemoglobin protein to function improperly. Contrastingly, a nonsense mutation occurs when a substitution results in a premature stop codon, terminating protein synthesis too early and often producing a shortened, non-functional protein.
A silent mutation is a change that does not cause a change in the amino acid sequence of the resultant protein, which may have no effect on the organism. Lastly, a frameshift mutation happens due to the insertion or deletion of nucleotides that shifts the reading frame of the sequence, potentially causing extensive changes to the protein or creating a non-functional protein.
When comparing these mutations, it's clear that each has different potential impacts on protein synthesis. Silent mutations may go unnoticed within the organism, whereas missense and nonsense mutations can have severe or even lethal consequences if they result in a dysfunctional protein that plays a crucial role in the body. Frameshift mutations tend to be the most severe because they usually alter the entire amino acid sequence downstream of the mutation.