Protozoa and Its Features

Protozoa:- Single-celled eukaryotes or organisms that possess membrane-bound organelles and nuclei are known as Protozoa. Originally, protozoa had been defined as unicellular protists with animal-like behavior, e.g., movement. Protozoa were regarded as the partner group of protists to protophyta, which have plant-like behaviour, e.g., photosynthesis. The word protozoa means "little animal." They are so named because many species behave like tiny animals-specifically, they hunt and gather other microbes as food.

 

Features:

1. Protozoa commonly range from 10 - 52 micrometers, but can grow as large as 1 mm, and are seen easily by microscope. 
2. The largest protozoa known are the deep-sea dwelling xenophyophores, which can grow up to 20 cm in diameter. They were considered formerly to be part of the protista family. 
3. Protozoa exist throughout aqueous environments and soil, occupying a range of tropic levels. 
4. Protozoa mainly feed on bacteria, but they also eat other protozoa, bits of stuff that has come off of other living things-what's generally called organic matter-and sometimes fungi.

Classification :- The classification of protozoa has been and remains a problematic area of taxonomy. Where they are available, DNA sequences are used as the basis for classification but for the majority of described protozoa such material is not available. They have been and still are mostly on the basis of their morphology and for the parasitic species their hosts. Protozoa have been divided traditionally on the basis of their means of locomotion.

Sub Groups of protoza
Flagellates (e.g Giardia lamblia)
Amoeboids (e.g. Entamoeba histolytica)
Sporozoans (e.g.Plasmodium knowlesi)
Ciliates ( ( e.g. Balantadium Coli)