Notes of microorganisms friend and foe from DAV book
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Answer:
microorganism friend and foe
Microbes are classified into four groups as:
Protozoa
Bacteria
Fungi
Algae
Introduction
Microorganisms
Microorganisms are microscopic organisms that cannot be seen with the naked eye.
These organisms are usually unicellular in nature.
Bacteria
Bacteria are unicellular prokaryotic microorganisms.
Some bacteria are useful for humans while some can be harmful.
They are of four major types: Bacillus, Vibrio, Cocci and Spirilla
Fungi
Fungi are saprophytic or parasitic organisms.
They are mostly multicellular and not microscopic.
However, yeast is a unicellular and microscopic organism.
Fermentation
Fermentation is a metabolic process that converts sugar to acids, gases or alcohol.
Fermentation is used in the preparation of curd and alcohol.
Protozoa
Protozoa are single-celled microscopic animals which include flagellates, ciliates, sporozoans, and many other forms.
Few examples are: amoeba, paramecium, euglena, plasmodium etc
Viruses
Viruses are organisms that possess nucleic acid but lack the replicating machinery.
Thus, a virus cannot survive without a living cell.
Viruses are also considered to be on the borderline between living and nonliving entities.
Few examples are: influenza virus, HIV, Rabies virus, poliovirus, tobacco mosaic virus etc
Vaccines
A vaccine is a biological preparation that provides active acquired immunity to a disease.
Vaccines are usually made for viral diseases.
Few examples are Salk vaccine for Polio, Influenza vaccine, Rabies vaccine etc
Antibiotics
Antibiotics is an inorganic or organic compound that inhibits and kills microorganisms.
Antibiotics usually target bacteria.
Thus most of the bacterial diseases are treated with antibiotics.
Pathogens
A pathogen is any organism that causes disease.
Bacteria, protozoa and viruses can be pathogenic.
They can spread the infection since they already have the pathogen in their bodies.
Vector
Vector is an organism, which is a biting insect or tick, that can transmit a disease or parasite from one animal or plant to another.
Airborne diseases
Certain diseases can spread by air.
These diseases are called airborne diseases.
Influenza is the best example of this type of disease.
Waterborne diseases
The diseases that spread through water are called waterborne diseases.
Contaminated water is hosts to several pathogens.
Typhoid is the best example of waterborne disease.
Examples of Diseases
Human diseases Causative Organism Mode of Transmission
Tuberculosis Bacteria Air
Measles Virus Air
Plant diseases
Certain pathogens can cause diseases in plants. Just like humans, plants can be attacked by bacteria or virus.
Several micro-organisms cause diseases in plants like rice, potato, wheat, sugarcane, orange, apple and others.
Food poisoning
When food contaminated with pathogens or toxins are consumed, it causes food poisoning.
The most common symptom is a pain in the stomach.
In severe cases, food poisoning can also cause death.
Food preservation
Certain chemicals inhibit the growth of bacteria and increase the life of the cooked food.
Certain simple preservation methods can be carried out at our home.
Chemical methods
Chemical preservatives are used in food preservations by major food industries as they are harmless to humans.
Sodium meta-bisulphate and sodium benzoate are commonly used chemical preservatives.
Uses of common salt
Common salt also known as sodium chloride is used as a preservative at home.
Vegetables are pickled using salt as the salt removes water and kills bacteria and fungus cells.
Preservation by Sugar
Sugar is used for the preservation of jams, jellies and squashes.
The growth of microbes is restricted by the used of sugar as it reduces the moisture content.
Preservation by oil and Vinegar
Many food preparations like pickles are preserved by adding either oil or vinegar to them.
Bacteria cannot grow in such medium.
Pasteurization
Pasteurization is a process of superheating and cooling the beverages to kill pathogenic microbes.
Storage and Packing
Dry fruits and many vegetables are preserved in airtight/air sealed containers.
The absence of air prevents the growth of bacteria or fungi.
Nitrogen Cycle
The nitrogen cycle is a biogeochemical cycle by which nitrogen is converted into various chemical forms as it circulates among the atmosphere and terrestrial and marine ecosystems.