Question

which of the following describes mutations? neutral mutations depend on the degeneracy of the genetic code. point mutations can occur in any dna sequence. frameshift mutations can occur in any dna sequence. deleterious mutations occur only in protein - coding sequences of dna.

Explanation:

• For the option "Neutral mutations depend on the degeneracy of the genetic code": The genetic code is degenerate (multiple codons can code for the same amino acid). A neutral mutation is a change in DNA that doesn't change the encoded amino acid (due to degeneracy), so this statement is correct.
• For "Point mutations can occur in any DNA sequence": Point mutations are changes in a single nucleotide. However, not all DNA sequences are equally prone, and some regions (like highly conserved regulatory regions) have mechanisms to prevent mutations, so this is incorrect.
• For "Frameshift mutations can occur in any DNA sequence": Frameshift mutations (insertions/deletions not in multiples of 3) affect the reading frame. But they require a sequence where insertions/deletions can happen, and non - coding or certain structured DNA may not be as likely, and also, if the DNA sequence length is not suitable (e.g., very short), frameshift may not be possible in the way implied, so this is incorrect.
• For "Deleterious mutations occur only in protein - coding sequences of DNA": Deleterious mutations can occur in non - coding DNA (e.g., regulatory regions that control gene expression) and harm the organism, so this is incorrect.

Answer:

A. Neutral mutations depend on the degeneracy of the genetic code.