Excretion by protonephridia with solenocyte is a characteristic of

Options

A. Branchiostoma
B. Amphioxus
C. Lancelet
D. All of these

Answer

To solve the question "Excretion by protonephridia with solenocyte is a characteristic of," we can follow these steps:

### Step 1: Understand the Terms
- **Protonephridia**: These are excretory structures found in certain invertebrates, primarily involved in osmoregulation and excretion.
- **Solenocytes**: Also known as flame cells, these are specialized cells within protonephridia that help in the excretion process.

### Step 2: Identify the Organisms
- The question provides four options, and we need to determine which of these organisms possess protonephridia with solenocytes.

### Step 3: Analyze the Options
1. **Brachiostoma**: Also known as Amphioxus, it is a type of lancelet and is part of the subphylum Cephalochordata. It does not have protonephridia with solenocytes.
2. **Amphioxus**: This is another name for Brachiostoma, so it shares the same characteristics as mentioned above.
3. **Platyhelminthes**: This phylum includes flatworms, which are known to have protonephridia with solenocytes (flame cells) for excretion.
4. **Lenslet**: This seems to be a typographical error or misrepresentation, as it does not correspond to a known organism in this context.

### Step 4: Conclusion
- The presence of protonephridia with solenocytes is characteristic of organisms in the phylum **Platyhelminthes**. Therefore, the correct answer is **option 4: all of these**, as it includes organisms that utilize this excretory system.

### Final Answer
The correct answer is **option 4: all of these**.

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