MICRO-ORGANISMS : FRIENDS or FOE ncert_class8

•Micro organisms are classified into Four Major Groups 

  i.e BACTERIA ,FUNGI, PROTOZOA , ALGAE 

•Viruses are also microscopic

•Algae and Fungi comes under multicellular microscopic organisms

 and they can survive under all type of Environment 

•Friendly micro-organisms used to make Curd ,bread and cake and 

alcohol also 

 

•BACTERIUM LACTOBACILLUS used to make Curd

•Mainly bacteria are used for : Preparation of medicines , to

 increase soil fertility, food etc

 

•Yeast is generally used in baking industry for making bread ,

pastries and cakes as they produce carbon dioxide during 

respiration and thus bubbles of the gas fill the dough  and increase

 its volume

•Some bacteria and blue green algae are able to fix Nitrogen from the atmosphere to enrich soil with nitrogen and increase its fertility . These microbes are commonly called Biological Nitrogen Fixer. 

 • Disease causing micro-organisms are called Pathogens. •Anopheles Mosquito carries parasite of Malaria .  
•Aedes Mosquito acts as a carrier of Dengue Virus  

•What is PASTEURIZATION ??  

 it is the partial sterilization of a product such as milk or wine

to make it safe for consumption and improve its keeping 

quality . It reduces the risk of food poisoning .