Phasmids of Ascaris are

Options

A. tactile
B. chemoreceptor
C. photoreceptor
D. 1) and 3)

Answer

To solve the question regarding the phasmids of Ascaris, we will go through the following steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the function of phasmids in Ascaris. We need to identify what type of sensory receptors they are.

2. **Identifying Ascaris**: Ascaris is a genus of parasitic roundworms belonging to the phylum Nematoda (also known as roundworms). Understanding its classification helps in knowing its biological characteristics.

3. **Sensory System of Ascaris**: Ascaris has a specialized sensory system that includes various types of sensory cells. The main types of sensory cells mentioned are:
- Papillae
- Amphids
- Phasmids

4. **Function of Sensory Cells**:
- **Papillae**: These are tactile receptors that respond to touch.
- **Amphids**: These are chemoreceptors that detect chemical stimuli.
- **Phasmids**: These are also chemoreceptors that are located on the lateral sides of the posterior end of the Ascaris.

5. **Conclusion**: Since phasmids are identified as chemoreceptors, the correct answer to the question is that phasmids of Ascaris are chemoreceptors.

6. **Final Answer**: The correct option is **Option 2: Chemoreceptor**.