In the context of DNA structure, why do scientists classify DNA as a macromolecule?

• A. Because DNA is a very large polymer made of many repeating nucleotide subunits linked into long strands.
• B. Because DNA is a lipid-based molecule whose main function is energy storage.
• C. Because DNA is a small monomer that cannot be broken into simpler units.
• D. Because DNA is an inorganic crystal lattice with no repeating subunits.

Answer: (A)

Verified step by step guidance

1. Understand the definition of a macromolecule: Macromolecules are very large molecules typically composed of repeating smaller units called monomers.
2. Recall the structure of DNA: DNA is made up of nucleotide subunits, each consisting of a sugar, phosphate group, and nitrogenous base.
3. Recognize that these nucleotides are linked together in long chains, forming a polymer.
4. Connect the concept that because DNA is a long polymer made of many repeating nucleotide units, it fits the definition of a macromolecule.
5. Eliminate incorrect options by noting that DNA is not lipid-based, not a small monomer, and not an inorganic crystal lattice.