A current of water is produced in Branchiostoma by

Options

A. Cilia
B. Cirri
C. Wheel organ
D. Rostrum

Answer

To answer the question "A current of water is produced in Branchiostoma by," we will analyze the options provided and determine which structure is responsible for creating the water current necessary for feeding in this organism.

### Step-by-Step Solution:

1. **Understanding Branchiostoma**:
- Branchiostoma, also known as amphioxus, is a member of the phylum Chordata and subphylum Cephalochordata. It is primarily found in marine environments.

2. **Purpose of Water Current**:
- The water current in Branchiostoma is essential for the ingestion of food. It helps bring food particles into the organism for feeding.

3. **Analyzing the Options**:
- **Option A: Celia**:
- Cilia are hair-like structures that can create currents in some organisms. However, Branchiostoma does not possess cilia, so this option is incorrect.

- **Option B: Ceri (Buccal Cera)**:
- The buccal cera, or cirri, are filament-like structures that form a ring around the mouth of Branchiostoma. They play a crucial role in generating the water current necessary for feeding. This option is likely correct.

- **Option C: Wheel organ**:
- The wheel organ is located in the buccal cavity and is involved in feeding but does not directly create the water current. Therefore, this option is incorrect.

- **Option D: Rostrum**:
- The rostrum is the snout or beak-like structure at the front of the organism. It does not contribute to the formation of the water current, making this option incorrect.

4. **Conclusion**:
- After analyzing all the options, the correct answer is **Option B: Ceri (Buccal Cera)**, as they are responsible for producing the water current in Branchiostoma.

### Final Answer:
The current of water in Branchiostoma is produced by **Ceri (Buccal Cera)**.

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