Nucleic Acids
Which of the following bases is present in RNA but NOT in DNA?
Select the correct option:
Solution
Uracil
RNA contains the four nitrogenous bases: Adenine (A), Guanine (G), Cytosine (C), and Uracil (U). DNA contains Adenine, Guanine, Cytosine, and Thymine (T). Uracil (a pyrimidine lacking the 5-methyl group of thymine) is unique to RNA and pairs with Adenine during transcription. The presence of thymine (instead of uracil) in DNA is thought to improve the genetic stability of the double helix.
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About This Question
- Subject
- chemistry
- Chapter
- biomolecules
- Topic
- nucleic acids
- Difficulty
- Easy
- Year
- 2025
Solution
Correct Answer:
Uracil
RNA contains the four nitrogenous bases: Adenine (A), Guanine (G), Cytosine (C), and Uracil (U). DNA contains Adenine, Guanine, Cytosine, and Thymine (T). Uracil (a pyrimidine lacking the 5-methyl group of thymine) is unique to RNA and pairs with Adenine during transcription. The presence of thymine (instead of uracil) in DNA is thought to improve the genetic stability of the double helix.
This easy difficulty chemistry question is from the chapter biomolecules, covering the topic of nucleic acids. It appeared in the 2025 exam.
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