Important Plant Pathogenic Organism – Protozoa
Protos –Primitive Zoon- animal
1. Protozoa are single celled, non photothetic, eukaryotic animal like organisms.
2. Their size ranges from 2-3 micron. They lack rigid cell wall and do not contain chlorophyll.
3. They make their movements with the help of cilia, flagella or pseudopodia.
4. They are widely distributed in nature particularly in aquatic, environment or moist habitats.
5. Most of the protozoa are free living but some are symbiotic or parasitic causing diseases in plants animals and humans.
6. Free living protozoa are commonly found in salt water, fresh water, sand, soil and decaying organic matter.
7. Protozoa reproduce sexually or asexually.
8. Asexually either by binary fission or by budding or by both means.
9. Sexually by fusion of two gametes.
10. They have characteristics ability to regenerate the lost parts of the body. E.g. Genera: Amoeba, Paramecium, Verticlia etc.
11. The free living protozoa play an important role in maintaining the ecological balance in nature.
12. It helps in purification of water as they utilize the inorganic nitrates and phosphates for their own metabolism.
13. It plays an important role in aerobic and anaerobic digestion of sewage by biological sewage treatment. E.g. Aerobic Paramaecium Anaerobic – Metopus.
Disease Caused by Protozoa:
1. Protozoa found in the stomach of cattle, sheep and fermites help in digestion of food.
2. It causes diseases in animals and humans. E.g. Malaria caused by Plasmodium malariae and Sleeping sickness in human beings.