Select the incorrectly matched pairs.

Options

A. Purines - Nitrogenous bases cytosine, thymine and uracil
B. Recombinant DNA - DNA formed by joining the DNA segments from two different sources.
C. rRNA - RNA found in ribosomes
D. ATP - The energy - carrying compound in the cell

Answer

To solve the question of selecting the incorrectly matched pairs, we will analyze each option provided in the question step by step.

### Step-by-Step Solution:

1. **Identify the First Pair: Purines - Nitrogenous bases, Cytosine, Thymine, and Uracil**
- Purines are a type of nitrogenous base that includes adenine (A) and guanine (G).
- Cytosine (C), Thymine (T), and Uracil (U) are not purines; they are pyrimidines.
- **Conclusion**: This pair is incorrectly matched.

2. **Identify the Second Pair: Recombinant DNA - DNA formed by joining DNA segments from two different sources**
- Recombinant DNA is indeed formed by combining DNA segments from different sources.
- This definition is accurate.
- **Conclusion**: This pair is correctly matched.

3. **Identify the Third Pair: RRNA - RNA found in ribosomes**
- RRNA (ribosomal RNA) is a component of ribosomes, which are responsible for protein synthesis.
- This statement is correct as RRNA is indeed found in ribosomes.
- **Conclusion**: This pair is correctly matched.

4. **Identify the Fourth Pair: ATP - Energy carrying compound in the cell**
- ATP (adenosine triphosphate) is known as the energy currency of the cell.
- This statement is accurate.
- **Conclusion**: This pair is correctly matched.

### Final Conclusion:
The only incorrectly matched pair is the first one: **Purines - Nitrogenous bases, Cytosine, Thymine, and Uracil**.