Question map
Not attempted Correct Incorrect ★ Bookmarked
Loading…
Q110 (NDA-I/2025) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Genetics and evolution Answer Verified

Which is the correct base pairing found in a normal DNA molecule?

Result
Your answer: —  Â·  Correct: A
Explanation

In a normal DNA molecule, the double helix structure is stabilized by complementary base pairing between nitrogenous bases on opposite strands. According to the Watson-Crick model, adenine (A), a purine, specifically pairs with thymine (T), a pyrimidine, through two hydrogen bonds [1]. Similarly, guanine (G) pairs with cytosine (C) through three hydrogen bonds [1]. This specific pairing ensures a uniform diameter of the DNA molecule and is the basis for Chargaff's rules, where the amount of adenine equals thymine and guanine equals cytosine. While adenine pairs with uracil in RNA, in the context of a normal DNA molecule, adenine only pairs with thymine [1]. Therefore, among the given options, only the pairing of Adenine with Thymine is correct.

Sources

  1. [1] https://www.sciencedirect.com/topics/immunology-and-microbiology/base-pairing
How others answered
Each bar shows the % of students who chose that option. Green bar = correct answer, blue outline = your choice.
Community Performance
Out of everyone who attempted this question.
50%
got it right
✓ Thank you! We'll review this.

SIMILAR QUESTIONS

IAS · 2004 · Q60 Relevance score: -0.18

Which of the following pairs are correctly matched ?

(Period) | (Wars)
1. AD 1767-69 | First Anglo Maratha War
2. AD 1790-92 | Third Mysore War
3. AD 1824-26 | First Anglo-Burmese War
4. AD 1845-46 | Second Sikh War

IAS · 2005 · Q140 Relevance score: -0.27

Which pairs are correctly matched?

Movement/Satyagraha | Person Actively Associated with
(A) Champaran | Rajendra Prasad
(B) Ahmedabad Mill Workers | Morarji Desai
(C) Kheda | Vallabhbhai Patel

IAS · 2004 · Q112 Relevance score: -1.04

Which of the following pairs is correctly matched?
Select the correct answer using the codes given below:

Department | Ministry of the Government of India
1. Department of : Women and Child Development | Ministry of Health and Family
2. Department of : Official Language | Ministry of Human Resource
3. Department of : Drinking Water Supply | Ministry of Water Resources

IAS · 2008 · Q103 Relevance score: -1.04

Which of the following pairs are correctly matched? Institute Location 1. National Centre for Cell Science Mysore 2. Centre for DNA Fingerprinting and Diagnostics Hyderabad 3. National Brain Research Centre Gurgaon Select the correct answer using the code given below: Code:

IAS · 2008 · Q120 Relevance score: -1.55

Which of the following pairs is/are correctly matched? 1. Francis Collins : Mapping human genome 2. Sergey Brin : Google Search Engine 3. Jimmy Wales : Wikipedia Select the correct answer using the code given below: Code: