Protozoa

Definition

Protozoa are single-celled eukaryotic microorganisms that can cause various infections in humans. They often inhabit water, soil, and other moist environments and can be parasitic.

5 Must Know Facts For Your Next Test

1. Protozoa are classified into groups such as amoeboids, flagellates, ciliates, and sporozoans based on their movement mechanisms.
2. Entamoeba histolytica is a protozoan responsible for amebic dysentery, a severe gastrointestinal infection.
3. Giardia lamblia causes giardiasis, characterized by diarrhea, stomach cramps, and nausea.
4. Transmission of protozoan infections typically occurs through contaminated food or water or via insect vectors.
5. Protozoa have complex life cycles often involving multiple hosts and stages such as trophozoite (active) and cyst (dormant) forms.

Review Questions

• What are the primary classifications of protozoa based on their movement mechanisms?
• Which protozoan is known to cause amebic dysentery?
• How are protozoan infections commonly transmitted?

Related terms

Amoeboids: A group of protozoa that move using pseudopodia.

Flagellates:

A type of protozoa that uses whip-like structures called flagella for movement.

Cysts: Dormant form of protozoa that helps them survive in harsh conditions.