Some Microscopic Organisms

There are various types of animals in the earth. There are microscopic organisms which cannot be seen by our naked eyes. They can only be seen by the microscope. Bacteria, virus and fungi are the microscopic organisms.

Bacteria

Bacteria are microscopic organisms whose single cells have neither a membrane-enclosed nucleus nor other membrane-enclosed organelles like mitochondria and chloroplasts. Bacteria was discovered by 'Anton Van Leeuwenhoek'. Bacteria can survive on air, water, land, animals and plants. Bacteria are in spherical, rod-shaped, coiled, comma and thread. Some examples of bacteria are coccus, bacillus, helical and vibrio.

Bacteria have no nucleus. Bacteria can be useful and harmful too. Rhizobium helps in nitrogen fixation.

Virus

Virus word is derived from Latin. They are an obligatory parasite and cannot survive outside the living host. The virus has characteristics of both living and non-living beings. Virus are made of Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA).

Virus divided according to its host:

1. Plant Viruses: The viruses that affect plants are classified under plant viruses. Example: TMV (Tobacco Mosaic Virus) etc.
2. Animal Viruses: The viruses that affect animals are classified under animal viruses. Example: Rabies, Rhino Virus etc.
3. Bacteriophage Virus: The viruses that affect bacteria are classified under bacteriophage. T1, T4 etc.

Fungi

Fungi have no chlorophyll. Some of the fungi are unicellular i.e. yeast and some are multicellular. Fungi can be both parasitic and saprophytic. Fungi gets its food from dead and decayed substances.

Fungi is made up of the collection of filament called hyphae. Fungi reproduce by fragmentation, budding, fission and sporulation. These are all asexual reproduction. Yeast is used to make an alcoholic beverage. The mushroom is also a fungus.