Microorganisms

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Microorganisms are very small organisms that   are harmful and causes diseases,often called germs.
they are so small to be visible  to naked eyes hence called microbes  or microorganisms.
                   They are present almost everywhere such as air,water, deserts,food,inside your body etc.
In unfavourable condition,microbes develope a hard outer covering around themselves as cyst.They  remain inactive within the cyst till favourable condition are present.

                                CLASSIFICATION OF MICROORGANISMS

Microbes are classified into 5 major group
Bacteria - They are simple, single celled organisms.They are of three shape

•  bacillus(rod-shaped),
• cocci(spherical) and 
• spirilla(spiral- shaped).They are autotrophic,saprotrophic,heterotrophic.

1. Algae-They are autotropic organism with undifferentiated plant bodies.They are found in aquatic habitats.eg. Chlamydomonas,Spirogyra,Laminaria
2. Fungi- They are plant-like organism that are heterotrophic (saprophytic and parasitic)in nutrition.
3. Protozoa-Unicellular organisms and have properties like animals.They are mostly heterotrophic.They have locomotory structures that allow them to move around.eg Amoeba and Paramecium.
4. Viruses - They are the smallest microorganisms.They have the characteristics of living as well as non-living organisms.They enter the  living cell and divide,  when outside they act as non-living as they lack the cell-organelle for multiplication,they often kill the host cell.

                                              MICROBES ARE USEFUL ALSO

1. Some Blue Green Algae and bacteria are able to fix nitrogen from the atmosphere into the soil.They are found in the roots of the leguminous plant peas,beans(eg Rhizobium bacteria).This process is called Nitrogen Fixation .
2. Lactobacillus bacteria are used for preparing curd,cheese,pickles and other food item.Lacto bacillius bacteria are actually good bacteria and help us in digesting milk.When present in guts in adequate amount helps in digestion.
3. Yeast(fungus) often used in baking and brewery help in converting glucose present in food into ethyl alcohol and carbon di oxide.This process is called Fermentation.
4. They are used in preparing antibiotics also like Penicillin.Penicillin is obtained from fungus Penicillin notatum.this fungus is helpful in destroying  staphyllococcus bacteria.
5. Vaccines developed  for Thypoid,Tuberculosis,measles,polio,small pox etc are obtained from microorganisms only.Vaccines is a suspension of dead or weak microbes.Thwy are used to build immunity to our body.
6. In Ruminating Animals like cow,sheep etc some bacteria and protozoa resides in their stomach and help in digestion of cellulose.
7. Some bacteria like Psudomonas decompose sewage and other wastes in water.This helps in cleaning  the environment and water.
8. Bacteria  are also used in leather industry and  tea