Which mutation feature describes a substitution?

Which mutation feature describes a substitution?

• A. Insertion
• B. Deletion
• C. Translocation
• D. Substitution

Answer: (D)

Substitution is a mutation in which a single nucleotide in the DNA sequence is replaced with a different nucleotide. This differs from an insertion, which adds extra bases; a deletion, which removes bases; and a translocation, which relocates a piece of DNA to another position or chromosome. For example, changing the sequence ATCG to AGCG substitutes the second base T with G, keeping the overall length the same. Because the change is a replacement rather than an addition, removal, or relocation of DNA, this description matches substitution. Such a change can affect the encoded protein depending on where it occurs and which amino acid is encoded.

Substitution is a mutation in which a single nucleotide in the DNA sequence is replaced with a different nucleotide. This differs from an insertion, which adds extra bases; a deletion, which removes bases; and a translocation, which relocates a piece of DNA to another position or chromosome. For example, changing the sequence ATCG to AGCG substitutes the second base T with G, keeping the overall length the same. Because the change is a replacement rather than an addition, removal, or relocation of DNA, this description matches substitution. Such a change can affect the encoded protein depending on where it occurs and which amino acid is encoded.