Question

Given below are two statements:
Statement (I): DNA, RNA and proteins are micromolecules.
Statement (II): Nucleotide and amino acids are monomers of DNA/RNA and proteins, respectively. Choose the most appropriate answer from the options given below:

• A. Both Statement (I) and Statement (II) are correct.
• B. Both Statement (I) and Statement (II) are incorrect.
• C. Statement (I) is correct but Statement (II) is incorrect.
• D. Statement (I) is incorrect but Statement (II) is correct.

Hint:

Macromolecules are large polymers assembled from smaller monomers. Think "macro" = large, "mono" = single.

Answer 1

The Correct Option is D

DNA, RNA, and proteins are classified as macromolecules due to their large size and complex structures. They are polymers made up of smaller repeating units. Statement (II) correctly identifies these monomers: nucleotides for DNA and RNA, and amino acids for proteins.

Answer 2

The micromolecule/macromolecule distinction rests on molecular size and whether a molecule is built from repeating monomer units. Micromolecules, such as glucose, amino acids or water, are single small units, while macromolecules are long chains of many such units joined together, giving them very high molecular weights. DNA, RNA and proteins are exactly this kind of chain - polymers built from nucleotide or amino-acid monomers - so calling them 'micromolecules' misclassifies them, making Statement (I) incorrect. Statement (II), by contrast, correctly names the monomer units of these polymers: nucleotides for the nucleic acids and amino acids for proteins. Hence Statement (I) is incorrect and Statement (II) is correct, option (4).