External coat composed of cellulose- like meaterial occurs in

Options

A. Hemichordate
B. Urochdate
C. Cephalochordate
D. Cyclostomata

Answer

To solve the question regarding which group of organisms has an external coat composed of a cellulose-like material, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks about an external coat made of a cellulose-like material. This indicates we are looking for a specific group of organisms that possess such a feature.

2. **Identify the Options**: The options given are:
- Hemichordate
- Urochordate
- Cephalochordate
- Cyclostomata

3. **Research the Groups**:
- **Hemichordates**: These are marine organisms that have a body divided into three parts but do not have a cellulose-like external coat.
- **Urochordates**: This group includes tunicates, which are known to have a protective outer covering called a tunic.
- **Cephalochordates**: These are small, fish-like organisms that do not have a cellulose-like coat.
- **Cyclostomata**: This group includes jawless fish like lampreys and hagfish, which do not have a cellulose-like external coat.

4. **Focus on Urochordates**: Among the options, urochordates are known for having a tunic, which is composed of a cellulose-like material called tunicin. This tunic serves as a protective covering for their bodies.

5. **Conclusion**: Based on the information gathered, the correct answer to the question is **Urochordate**.

### Final Answer:
The external coat composed of cellulose-like material occurs in **Urochordates**.

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