JEE Main 2024ChemistryBiomoleculesVitamins And Nucleic AcidseasyMCQ

JEE Main 2024 — Biomolecules Question with Solution

From: JEE Main 2024 (Online) 1st February Morning Shift

Question

If one strand of a DNA has the sequence ATGCTTCA, sequence of the bases in complementary strand is :

Choose an option

Show full solutionCorrect option: B
Correct answer
BTACGAAGT

Step-by-step explanation

DNA is made up of two strands that are complementary to each other. The base pairing rules state that adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G). Using these rules, we can determine the sequence of the complementary strand of the given DNA sequence ATGCTTCA. Here's the pairing for the given sequence:

A (adenine) pairs with T (thymine)

T (thymine) pairs with A (adenine)

G (guanine) pairs with C (cytosine)

C (cytosine) pairs with G (guanine)

T (thymine) pairs with A (adenine)

T (thymine) pairs with A (adenine)

C (cytosine) pairs with G (guanine)

A (adenine) pairs with T (thymine)

So, the complementary base sequence to the given DNA strand ATGCTTCA would be:

1. A pairs with T

2. T pairs with A

3. G pairs with C

4. C pairs with G

5. T pairs with A

6. T pairs with A

7. C pairs with G

8. A pairs with T

Putting it all together, the complementary sequence is: TACGAAGT. Therefore, the correct answer is: Option B - TACGAAGT

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About this question

This is a previous-year question from JEE Main 2024, covering the Biomolecules chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.