What type of mutation occurs due to a base-pair substitution that results in a codon coding for a different amino acid?

What type of mutation occurs due to a base-pair substitution that results in a codon coding for a different amino acid?

• A. Missense mutation
• B. Silent mutation
• C. Deletion
• D. Duplication

Answer: (A)

A missense mutation occurs when a base-pair substitution in the DNA sequence leads to the incorporation of a different amino acid in the resulting protein. This happens because the altered codon, formed due to the substitution, encodes for an amino acid different from the one that would be produced by the original codon. Such changes can impact the structure and function of the protein, depending on the specific amino acid that has been substituted and its role in the protein's overall structure. This is distinct from a silent mutation, which does not lead to a change in the amino acid sequence, thus having no effect on the protein. Other types of mutations, such as deletion and duplication, involve the loss or addition of nucleotides and affect the reading frame or sequence in different ways, rather than simply changing a single amino acid.

A missense mutation occurs when a base-pair substitution in the DNA sequence leads to the incorporation of a different amino acid in the resulting protein. This happens because the altered codon, formed due to the substitution, encodes for an amino acid different from the one that would be produced by the original codon. Such changes can impact the structure and function of the protein, depending on the specific amino acid that has been substituted and its role in the protein's overall structure. This is distinct from a silent mutation, which does not lead to a change in the amino acid sequence, thus having no effect on the protein. Other types of mutations, such as deletion and duplication, involve the loss or addition of nucleotides and affect the reading frame or sequence in different ways, rather than simply changing a single amino acid.