Totally parasitic protozoans belong to

Options

A. Ciliata
B. Sarcodina
C. Mastigophora
D. Sporozoa

Answer

**Step-by-Step Solution:**

1. **Understanding Parasitic Protozoans**:
- Parasitic protozoans are organisms that rely entirely on their host for nutrients. They invade the host's body and absorb nutrients, often causing harm to the host.

2. **Identifying the Types of Protozoans**:
- Protozoans can be classified into different groups based on their mode of nutrition. The main groups mentioned are:
- Ciliates (e.g., Paramecium)
- Sarcodina
- Mastigophora
- Sporozoa

3. **Analyzing Each Group**:
- **Ciliates**: These organisms, such as Paramecium, are heterotrophic but not parasitic. They consume food from their environment rather than relying on a host.
- **Sarcodina**: This group includes both holozoic (which can be parasitic) and heterotrophic forms. However, not all are strictly parasitic.
- **Mastigophora**: This group includes some parasitic members like Trypanosoma, but also has heterotrophic forms that do not depend on a host.
- **Sporozoa**: This group is characterized by organisms that are completely parasitic, such as those causing malaria and coccidia. They reproduce by forming spores and are entirely dependent on their host for survival.

4. **Conclusion**:
- Based on the analysis, the group that contains totally parasitic protozoans is **Sporozoa**. This group is known for its members that invade hosts and depend entirely on them for nutrition.

**Final Answer**: Totally parasitic protozoans belong to the group **Sporozoa**.

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