Which class does the malarial parasite belong to?

The correct answer is sporozoa.

Step-by-step Explanation:

1. The malarial parasite, scientifically known as Plasmodium, is a unicellular eukaryotic organism belonging to the kingdom Protista and the phylum Apicomplexa (often studied under protozoans).
2. Protozoans are traditionally classified into different classes based on their mode of locomotion:
- Sarcodina (e.g., Amoeba): Move and capture food using pseudopodia (false feet).
- Ciliata (e.g., Paramecium): Move using numerous hair-like cilia.
- Dinophyceae (Dinoflagellates): Are mostly marine photosynthetic protists with flagella, not parasitic protozoans.
- Sporozoa: Characterized by the absence of specialized locomotory organelles (like flagella, cilia, or pseudopodia) in their adult stage. They are exclusively endoparasites and typically reproduce by forming spores.
3. Since the malarial parasite (Plasmodium) is an endoparasite, lacks locomotory organs in its adult stage, and has a complex life cycle involving the formation of infectious spore-like stages (sporozoites), it belongs to the class Sporozoa.