Gujarat BoardEnglish MediumSTD 11 ScienceBIOLOGYBiomolecules1 Mark
MCQ
What replaces thymine in $\text{RNA:}$
A
Guanine
B
Adenine
✓
Uracil
D
Water
✓
Answer
Correct option: C.
Uracil
In $\text{RNA,}$ uracil binds to adenine via two hydrogen bonds.
In $\text{DNA,}$ the uracil nucleobase is replaced by thymine.
Uracil could be considered a demethylated form of thymine.
Each nucleotide in $\text{RNA}$ contains a ribose sugar, with carbons numbered $1'$ through $5'$. A base is attached to the $1'$ position, in general, adenine $(A),$ cytosine $(C),$ guanine $(G),$ or uracil $(U).$
Adenine and guanine are purines, cytosine and uracil are pyrimidines.
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