Incomplete alimentary canal with blind sac type of body planis present in

Options

A. Annelids
B. Arthropods
C. Plathyhelminthes
D. Sponges

Answer

To answer the question regarding which organism has an incomplete alimentary canal with a blind sac type of body plan, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Terms**:
- **Incomplete Alimentary Canal**: This means that the organism has a digestive system that does not have two separate openings (mouth and anus). Instead, it has a single opening that serves both functions.
- **Blind Sac Body Plan**: This refers to a body plan where the digestive cavity has only one opening and does not lead to a continuous digestive tract.

2. **Evaluate the Options**:
- **A. Annelida**: Annelids (like earthworms) have a complete alimentary canal, which means they have both a mouth and an anus. Therefore, this option can be ruled out.
- **B. Arthropoda**: Arthropods (like insects and crustaceans) also possess a complete alimentary canal. Thus, this option is also ruled out.
- **C. Platyhelminthes**: Flatworms (Platyhelminthes) have an incomplete alimentary canal and exhibit a blind sac body plan. This matches the criteria given in the question.
- **D. Sponges**: Sponges have a unique feeding system and do not have a true alimentary canal. They filter feed and do not fit the description of having a blind sac body plan.

3. **Conclusion**: Based on the evaluation, the only option that fits the description of having an incomplete alimentary canal with a blind sac type of body plan is **C. Platyhelminthes**.

### Final Answer:
The answer is **C. Platyhelminthes**.

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