Microorganisms Friend and Foe Extra Questions and Answers
Microorganisms- A living organism that is very minute to be seen by the naked eye, especially a single-celled organism, such as a bacterium is called a microorganism. Microorganisms are classified into four major groups mainly bacteria, fungi, protozoa, and some algae.
Q. Write the name of the bacteria that convert milk into curd.
Q. Name two diseases caused by protozoans.
Answer: Diseases like dysentery and malaria are caused by protozoans.
Q. Name two diseases caused by bacteria.
Answer: Typhoid and tuberculosis (T.B.).
Q. Name the process of conversion of sugar into alcohol.
Q. Name some of the diseases that can be prevented by vaccination.
Cholera, tuberculosis, smallpox, hepatitis, etc.
Q. How do microorganisms help to improve the fertility of soil?
Rhizobium bacteria present in the nodules of the roots of leguminous plants helps in the replenishment of the soil with nitrogen. Rhizobium bacteria takes nitrogen from the atmosphere and fix it directly into nitrogenous compounds and increase the fertility of the soil.
Q. What are antibiotics?
Ans: Antibiotics are the medicines which kill or stop the growth of the disease-causing microorganisms. The source of these medicines is micro-organisms.
Q. Name any two antibiotics?
Ans: Streptomycin, Tetracycline.
Q. How are antibiotics manufactured?
Ans: The antibiotics are manufactured by growing specific microorganisms which checks the growth of some other bacteria or microorganisms. Antibiotics are used to cure a variety of diseases. They are also used to control many plant diseases.
Q. How are bacteria beneficial to us? Explain by giving three examples.
Bacteria are very useful to human beings though some other bacteria are harmful too.
Following are some examples that are very useful to us :
- Rhizobium: Rhizobium bacteria and blue-green algae present in the soil fix nitrogen from the atmosphere and convert it into nitrogenous compounds.
- Lactobacillus: Lactobacillus bacteria are useful in making curd from milk.
- Decomposers: Bacteria play an important role in cleaning the environment by decomposing the dead organic matter.
Q. How can nitrogen be replenished in soil? Explain with an example.
Nitrogen in the soil can be replenished by two different ways :
Rhizobium bacteria present in the nodules of the roots of leguminous plants help in the replenishment of the soil with nitrogen. Rhizobium bacteria take nitrogen from the atmosphere and fix it directly into nitrogenous compounds. These crops are like beans and peas which with which it has a symbiotic relationship Rhizobium.
Nitrogen sometimes gets fixed through the action of lightning in the clouds. High temperature generated in the lightning fixes the nitrogen to nitrogenous compounds.
Q. What is nitrogen cycle?
The process of consumption of nitrogen by living beings (animals and plants), taking it from the atmosphere and returning back to the atmosphere by various processes, is called nitrogen cycle.
Q. What are pathogens? Write another name of pathogens.
Disease-causing microorganisms are known as pathogens. They are also called germs.
Q. What is fermentation?
Fermentation is the process of conversion of food into alcohol.
Q. What is vaccine?
A substance which is used in the production of immunity against various diseases in the living body is termed as vaccine.
Q. Define communicable diseases. Give some examples.
Communicable diseases are microbial diseases that can spread from an infected person to a healthy person through air, water, or other physical contacts.
E.g., cholera, chicken pox, tuberculosis, common cold, etc.
Q. What is pasteurisation?
Pasteurisation can be defined as the partial sterilisation of foods at a temperature that destroys harmful microorganisms without major changes in the chemical property of the food.