summary of the chapter microorganisms: friend and for Related: Summar...
Summary
- Microorganisms are not visible to the naked eye.
- They can live in all kinds of environment, ranging from ice cold climate to hot springs and deserts to marshy lands.
- Microorganisms are found in air, water and in the bodies of plants and animals. They may be unicellular or multicellular.
- Microorganisms include bacteria, fungi, protozoa, and some algae.
- Viruses reproduce only inside the host organism, bacterium, plant or animal cell.
- Some microorganisms are useful for commercial production of medicines and alcohol.
- Some microorganisms decompose organic waste and dead plants and animals into simple substances and clean up the environment.
- Protozoans cause serious diseases like dysentery and malaria.
- Some micro-organisms grow on our food and cause food poisoning.
- Root-nodule bacteria of legumes can fix nitrogen from the air into the soil and increase soil fertility.
- Some bacteria and blue-green algae present in the soil fix nitrogen from the atmosphere and convert into nitrogenous compounds
- Certain bacteria convert compounds of nitrogen present in the soil into nitrogen gas which is released to the atmosphere.