Exonuclease III degrades which of the following?

Exonuclease III is an enzyme that specifically degrades DNA from the 3' end, and notably, it exhibits a preference for double-stranded DNA. It acts by sequentially removing nucleotides one by one, starting from the 3' terminus. This allows it to effectively degrade the 5' mononucleotides from the 3' end of a double-stranded DNA molecule, which is precisely what the correct option describes.

The specificity of Exonuclease III is essential to understand its function in molecular biology, particularly in applications involving DNA manipulation, such as cloning and sequencing. The incorrect options may not accurately reflect the enzyme's activity or the substrates it targets. For instance, single-stranded DNA and RNA molecules are not efficiently degraded by Exonuclease III, as its action is specifically tailored for double-stranded structures, highlighting the enzyme's unique characteristics and its important role in various molecular techniques.