Question

Choose the incorrect statements among the following
1. Purines and cytosine are common in DNA and RNA.
2. Thymine is present only in RNA.

3. Uracil is present in DNA at the place of Thymine.
4. Adenine and Guanine are Purines

• A. I and II
• B. II and III
• C. I and III
• D. III and IV

Hint:

Remember: Thymine is found only in DNA, while Uracil replaces it in RNA. Adenine and Guanine are purines present in both nucleic acids.

Answer 1

The Correct Option is B

Step 1: Analyze each statement
- I. Purines and cytosine are common in DNA and RNA — This is correct. Purines (adenine, guanine) and cytosine are found in both DNA and RNA.
- II. Thymine is present only in RNA — Incorrect. Thymine is found only in DNA, not RNA.
- III. Uracil is present in DNA at the place of Thymine — Incorrect. Uracil is found in RNA, not DNA.
- IV. Adenine and Guanine are Purines — This is correct. Step 2: Conclusion
Statements II and III are incorrect.