Johnston's organs are meant for perceiving

Options

A. Mechanical and sound vibrations
B. Smell
C. Taste
D. Temperature.

Answer

### Step-by-Step Solution:

1. **Understanding Johnston's Organs**: Johnston's organs are specialized sensory structures found in certain insects, particularly located in the pedicel of their antennae. They consist of a collection of sensory cells.

2. **Function of Johnston's Organs**: These organs are primarily responsible for detecting motion, particularly through the movement of the flagellum (the long, slender part of the antenna). They play a crucial role in the insect's ability to perceive changes in their environment.

3. **Role in Flight Stability**: Johnston's organs are important for controlling flight stability in insects such as hawks and moths. This indicates that they are sensitive to mechanical stimuli, specifically vibrations.

4. **Analyzing the Options**: The question provides four options:
- Option 1: Mechanical and sound vibration
- Option 2: Smell
- Option 3: Taste
- Option 4: Temperature

5. **Identifying the Correct Answer**: Given that Johnston's organs are involved in detecting mechanical vibrations and sound, the correct answer is **Option 1: Mechanical and sound vibration**. The other options (smell, taste, temperature) do not relate to the function of Johnston's organs.

### Final Answer:
Johnston's organs are meant for perceiving **mechanical and sound vibration**.

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