Acraniata includes

Options

A. Urochordata
B. Protochordata
C. Cephalochordata
D. All of these

Answer

To answer the question "Acraniata includes," we need to understand the classification of organisms within the subphylum Acraniata, which is part of the phylum Chordata. Here’s a step-by-step breakdown of the solution:

### Step-by-Step Solution:

1. **Understanding Acraniata**:
- Acraniata is a subphylum within the phylum Chordata.
- The term "Acraniata" refers to organisms that do not possess a cranium (a true skull).

2. **Relation to Chordata**:
- Chordata is divided into two main subphyla:
- **Craniata (or Vertebrata)**: These organisms have a cranium.
- **Acraniata (or Protochordata)**: These organisms lack a cranium.

3. **Classification of Acraniata**:
- The subphylum Acraniata is further divided into three main groups:
- **Hemichordata**: These are marine organisms that have some chordate features but are not true chordates.
- **Cephalochordata**: These are small, fish-like organisms that retain chordate characteristics throughout their lives.
- **Urochordata**: Also known as tunicates, these organisms have a larval stage that exhibits chordate characteristics.

4. **Conclusion**:
- Therefore, Acraniata includes:
- Urochordata
- Cephalochordata
- Hemichordata
- Hence, the correct answer is that Acraniata includes all of these groups.

### Final Answer:
Acraniata includes Urochordata, Cephalochordata, and Hemichordata.