Hydra can paralyse prey by

Options

A. nematocysts
B. tentacles
C. mouth
D. none of these

Answer

### Step-by-Step Solution:

1. **Identify the Organism**: The question is about Hydra, which is a type of freshwater cnidarian known for its simple body structure and ability to capture prey.

2. **Understand the Mechanism of Prey Capture**: Hydra captures its prey using specialized cells located in its tentacles.

3. **Identify the Specialized Cells**: These specialized cells are called nematocytes (also known as cnidocytes). They are crucial for the Hydra's feeding mechanism.

4. **Function of Nematocytes**: Nematocytes contain a stinging structure that can inject a neurotoxin into the prey. This neurotoxin is responsible for paralyzing the prey.

5. **Process of Paralysis**: When the nematocytes come into contact with the prey, the neurotoxin is released, which suppresses the nervous system of the prey, leading to paralysis.

6. **Conclusion**: Therefore, Hydra can paralyze its prey by using nematocytes that inject neurotoxins into the prey, effectively immobilizing it for capture.

### Final Answer:
Hydra can paralyze prey by using **nematocytes** that inject neurotoxins into the prey.

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