Which of these statements of comparison regarding DNA and RNA holds true ?

Options

A. DNA chemically is less reactive and structurally less stable when compared to RNA.
B. DNA chemically is more reactive and structurally less stable when compared to RNA.
C. DNA chemically is less reactive and structurally more stable when compared to RNA.
D. DNA chemically is more reactive and structurally more stable when compared to RNA.

Answer

To solve the question regarding the comparison of DNA and RNA, we need to analyze the properties of both nucleic acids and determine which statement is true based on their chemical reactivity and structural stability.

### Step-by-Step Solution:

1. **Understand the Composition of DNA and RNA**:
- DNA stands for deoxyribonucleic acid and contains deoxyribose sugar.
- RNA stands for ribonucleic acid and contains ribose sugar.

2. **Analyze the Sugar Structure**:
- Both DNA and RNA are made up of pentose sugars (five carbon atoms).
- The difference lies in the second carbon: ribose has a hydroxyl group (–OH) at the second carbon, while deoxyribose has only a hydrogen atom (–H) at that position.

3. **Chemical Reactivity**:
- The presence of the hydroxyl group in ribose makes RNA more reactive than DNA. This is because the –OH group can participate in chemical reactions, making RNA less stable.
- Conversely, DNA, lacking the hydroxyl group at the second carbon, is less reactive and therefore more stable.

4. **Structural Stability**:
- Due to its chemical structure, DNA is more stable than RNA. This stability is crucial for DNA's role in storing genetic information.

5. **Evaluate the Given Options**:
- **Option 1**: DNA chemically is less reactive and structurally less stable. (Incorrect)
- **Option 2**: DNA chemically is more reactive and structurally less stable. (Incorrect)
- **Option 3**: DNA chemically is less reactive and structurally more stable compared to RNA. (Correct)
- **Option 4**: DNA chemically is more reactive and structurally more stable. (Incorrect)

6. **Conclusion**:
- The correct statement is: "DNA chemically is less reactive and structurally more stable when compared to RNA."

### Final Answer:
The correct statement regarding the comparison of DNA and RNA is: **DNA chemically is less reactive and structurally more stable when compared to RNA.**

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