Micro-organisms Organisms that can be seen only with the help of a microscope are called micro-organisms.

Micro – organisms are of 6 types. 

1. Virus : They are the minutest structures. They are also called the connecting link between living and non-living because they possess both living as well as non – living characteristics.

2. Micro plasma : It is the smallest cell which can be sieved even through a virus filter. It causes diseases in plants.

3. Bacteria : They are unicellular prokaryotes. Bacteria are found in all places around us.

4. Fungi : They are micro-organisms with simple structure and can be unicellular or multi cellular. Science They lack chlorophyll in their cells. So, they can not prepare their own food.

5. Protozoa : They are unicellular organisms. Example : amoeba, paramecium etc.

6. Algae : They are micro – organisms having simple structure and may be unicellular or multi – cellular. Water in ponds, puddles and drains appear green due to the presence of algae.