Which of the following sets consist of pseudocoelomate organisms ?

Options

A. Ascaris , Ancylostoma
B. Fasciola, Earthworm
C. Roundworm , Taperworm
D. Taenia , Fasciola

Answer

To determine which set consists of pseudocoelomate organisms, we need to understand what pseudocoelomates are and identify the organisms in the given options.

### Step-by-Step Solution:

1. **Understanding Coelom Types**:
- Organisms are classified based on their body cavity (coelom). There are three types:
- **Acoelomates**: No body cavity (e.g., flatworms).
- **Coelomates**: True body cavity (e.g., annelids, mollusks).
- **Pseudocoelomates**: False body cavity, which is a fluid-filled space between the endoderm and mesoderm (e.g., roundworms).

2. **Identifying Pseudocoelomate Organisms**:
- Pseudocoelomates belong to the phylum **Nematoda** (roundworms) and **Rotifera**.
- Common examples include **Ascaris** (a type of roundworm) and **Encyclostoma** (hookworm).

3. **Analyzing the Options**:
- **Option 1: Ascaris and Encyclostoma**: Both belong to the phylum Nematoda and are pseudocoelomates.
- **Option 2: Fasciola and Earthworm**: Fasciola (liver fluke) belongs to Platyhelminthes (acoelomate), and Earthworm belongs to Annelida (coelomate).
- **Option 3: Roundworm and Tapeworm**: Roundworm (pseudocoelomate) is correct, but Tapeworm (Platyhelminthes) is an acoelomate.
- **Option 4: Tinea and Fasciola**: Both belong to Platyhelminthes and are acoelomates.

4. **Conclusion**:
- The only option that consists of pseudocoelomate organisms is **Option 1: Ascaris and Encyclostoma**.

### Final Answer:
The correct set that consists of pseudocoelomate organisms is **Ascaris and Encyclostoma**.