Question

Write a note on Virus, Bacteria, Protozoa?

Answer 1

Bacteria constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length
A virus is a small infectious agent that replicates only inside the living cells of other organism
Protozoa are a diverse group of mostly mobile unicellular eukaryotic organisms, but the term is no longer used in modern taxonomy. 

Answer 2

Virus:
         they are so small that the cannot be seen using a simple microscope,it should be seen in an electron microscope.they are very hard to classify as a living thing or a non living thing,on their own,they show no sign of life.however they reproduce in the cells of organisms like plants,animals,and,bacteria.tobacco mosaic virus (tmv) and humun immunodeficiancy virus(HIV).

bacteria:
            they are the smallest and oldest organisms on our planet and are found in our planet and are found in four different shape
(i) rod shaped-(bacilli)
(ii) spherical-(cocci)
(iii) curved-(commas)
(iv spiral-(spirilla) 

protozoa: 
              they are group of animal-like,single cell organism.amoeba and paramoceium are the examples