Question

briefly describe the characteristics of the protozoan groups and name important pathogens in each group

Answer 1

Protozoans are microscoic organisms ranging in size from 10 to 50 micrometers. Protozoans are classified according to their morphology, motility, presence of cilia and flagella and the type of symbiotic relationship with their host into following groups.

1. Flagellates - Giardia Lamblia. They are free living and non photosynthetic. They posses flagella and use it for locomotion. They lack cell wall.

2. Amaeboids - Entamoeba histolytica. These groups are found in fresh water and moist soil. They lack periplast and their body is covered by calcareous shell. They use pseudopodia for locomotion.

3. Sporozoans - Plasmodium vivax. They are uninucleate and their body is covered by pedicle. Flagella and cila are absent in this group.

4. Ciiates - Balantidium coli. They possess numerous cilia on their body surface.