Logo
Jeeify
MCQEasyJEE 2026Nucleic Acids (DNA, RNA)

JEE Chemistry 2026 Question with Solution

Both human DNA and RNA are chiral molecules. The chirality in DNA and RNA arises due to the presence of _____

  • A

    Base unit

  • B

    Chiral phosphate unit

  • C

    L-sugar component

  • D

    D-sugar component

Answer

Correct answer:D

Step-by-step solution

Standard Method

Given: Human DNA and RNA are chiral molecules.

Find: Which component is responsible for the chirality of DNA and RNA.

The backbone of nucleic acids, DNA and RNA, is made of alternating sugar and phosphate units.

The sugars are D-ribose in RNA and D-2-deoxyribose in DNA, and these sugar units contain multiple chiral centers.

The phosphate unit is not the source of chirality here, and the bases are also not responsible for the overall chirality of these nucleic acids.

Therefore, the chirality in DNA and RNA arises due to the presence of D-sugar component.

The correct option is D.

Common mistakes

  • Choosing chiral phosphate unit is incorrect because the phosphate group in the nucleic acid backbone is not the origin of molecular chirality. Focus on the sugar stereocenters, which actually make DNA and RNA chiral.

  • Choosing L-sugar component is incorrect because nucleic acids contain D-ribose or D-2-deoxyribose, not L-sugars. Remember the biological convention for sugars present in DNA and RNA.

  • Choosing base unit is incorrect because nitrogenous bases do not account for the backbone chirality of nucleic acids. Identify the monomer part that contains multiple chiral centers, namely the sugar unit.

Practice more Nucleic Acids (DNA, RNA) questions

Get unlimited AI-adaptive practice, mastery tracking, and an AI tutor that explains every step — free to start.

Start free trialMore on Nucleic Acids (DNA, RNA)

Related questions