Which of the following is not a correct pair ?

Options

A. Renette cells - Ascaris humbricoides
B. Parapodia - Nereis
C. Plasmalemma - Amoeba
D. Pharyngeal - Union nephridia

Answer

To determine which of the following pairs is not correct, we need to analyze each pair given in the question.

### Step-by-Step Solution:

1. **Identify the first pair: Rennet cells and Ascaris lumbricoides.**
- Rennet cells are indeed an excretory organ found in Ascaris lumbricoides, which is a type of roundworm.
- **Conclusion:** This pair is correct.

2. **Identify the second pair: Parapodia and Nereis.**
- Parapodia are appendages found on the sides of the body of Nereis, which is a type of polychaete worm. These structures assist in locomotion.
- **Conclusion:** This pair is also correct.

3. **Identify the third pair: Plasma lemma and Amoeba.**
- The plasma lemma is the cell membrane of Amoeba, which plays a role in regulating the water content within the organism.
- **Conclusion:** This pair is correct as well.

4. **Identify the fourth pair: Pharyngeal gill slits and Nephridia.**
- Pharyngeal gill slits are structures found in Lancelets (a type of cephalochordate) that are used for filter feeding. Nephridia, on the other hand, are excretory organs found in earthworms.
- **Conclusion:** This pair is not correct because pharyngeal gill slits do not relate to nephridia.

### Final Conclusion:
The pair that is not correct is **Pharyngeal gill slits and Nephridia**.