MP Board Class 12th Biology Solutions Chapter 10 Microbes in Human Welfare

by

MP Board Class 12th Biology Solutions Chapter 10 Microbes in Human Welfare

Microbes in Human Welfare NCERT Text Book Questions And Answers

Question 1.
Bacteria cannot be seen with the naked eyes, but these can be seen with the help of a microscope. If you have to carry a sample from your home to your biology laboratory to demonstrate the presence of microbes under a microscope, which sample would you carry and why?
Answer:
Curd can be used as a sample for the study of microbes. Curd contains numerous Lactic Acid Bacteria (LAB) or Lactobacillus. These bacteria produce acids that coagulate and digest milk proteins. A small drop of curd contains million of bacteria, which can be easily observed under a microscope.

Question 2.
Give example to prove that microbes release gases during metabolism.
Answer:
The examples of bacteria that release gases during metabolism are:

  • Bacteria and fungi carry out the process of fermentation and during this process, they release carbon dioxide.
  • The dough used for making idli and dosa gives a puffed appearance. This is because of the action of bacteria which releases carbon dioxide. This CO2 released from the dough gets trapped in the dough, thereby giving it a puffed appearance.

Question 3.
In which food would you find lactic acid bacteria ? Mention some of their useful applications.
Answer:
Lactic acid bacteria can be found in curd. It is this bacterium that promotes the formation of milk into curd. The bacterium multiplies and increases its number, which converts the milk into curd. They also increase the content of vitamin B12 in curd.

Lactic acid bacteria are also found in our stomach where it keeps a check on the disease-causing microorganisms.

MP Board Solutions

Question 4.
Name some traditional Indian foods made of wheat, rice and Bengal gram (or their products) which involve use of microbes. .
Answer:

  • Wheat product: Bread, Cake etc.
  • Rice product: Idli, dosa.
  • Bengal gram Product: Dhokla, Khandvi.

Question 5.
In which way have microbes played a major role in controlling diseases caused by harmful bacteria ?
Answer:
Several microorganisms are used for preparing medicines. Antibiotics are medicines produced by certain microorganisms to kill other disease-causing microorganisms. These medicines are commonly obtained from bacteria and fungi. They either kill or stop the growth of disease causing microorganisms.

Streptomycin, tetracycline and penicillin are common antibiotics. Penicillium notatum produces chemical penicillin, which checks the growth of staphylococci bacteria in the body. Antibiotics are designed to destroy bacteria by weakening their cell walls.

Question 6.
Name any two species of fungus, which are used in the production of the antibiotics.
Answer:
Antibiotics are medicines that are produced by certain microorganisms to kill other disease-causing microorganisms. These medicines are commonly obtained from bacteria and fungi. The species of fungus used in the production of antibiotics are :
MP Board Class 12th Biology Solutions Chapter 10 Microbes in Human Welfare 1

Question 7.
What is sewage ? In which way can sewage be harmful to us ?
Answer:
Sewage is the municipal waste-water collected from city or town homes, that contains toilet, bathroom and kitchen waste.

It contains large amounts of organic matter and many pathogenic microbes which are harmful to humans as they can cause many diseases like cholera, typhoid, polio.

Question 8.
What is the key difference between primary and secondary sewage treatment ?
Answer:
Differences between Primary and Secondary sewage treatment:
MP Board Class 12th Biology Solutions Chapter 10 Microbes in Human Welfare 2

Question 9.
Do you think microbes can also be used as source of energy ? If yes, how ?
Answer:
Yes, microbes can be used as a source, of energy. Bacteria such as; Methane bacterium is used for the generation of gobar gas or biogas. The generation of biogas is an anaerobic process in a biogas plant, which consists of a concrete tank (10-15 feet deep) with sufficient outlets and inlets. The dung is mixed with water to form the slurry and thrown into the tank.

The digester of the tank is filled with numerous anaerobic methane-producing bacteria, which produce biogas from the slurry. Biogas can be removed through the pipe which is then used as a source of energy, while the spent slurry is removed from the outlet and is used as a fertilizer.

Question 10.
Microbes can be used to decrease the use of chemical fertilizers and pesticides. Explain how this can be accomplished.
Answer:
Microbes play an important role in organic farming which is done without the use of chemical fertilizers and pesticides. Bio-fertilizers are living organisms which help increase the fertility of soil. It involves the selection of beneficial microorganisms that help in improving plant growth through the supply of plant nutrients. Bio-fertilizers are introduced in seeds, roots or soil to mobilize the availability of nutrients. Thus, they are extremely beneficial in enriching the soil with organic nutrients.

Many species of bacteria and cyanobacteria have the ability to fix free atmospheric nitrogen, Rhizobium is a symbiotic bacteria found in the root nodules of leguminous plants. Azospirillium and Azotobocter are free living nitrogen fixing bacteria, whereas Anabena, Nostoc and Oscillitoria are examples of nitrogen-fixing cyanobacteria. Bio-fertilizers are cost effective and eco-freindly.

Microbes can also act as bio-pesticides to control insect pest in plants. An example of bio-pesticides is Bacillus thuringiensis, which produces a toxin that kills the insect pests. Dried bacterial spores are mixed in water and sprayed in agricultural fields. When larvae of insects feed on crops, these bacterial spores enter the gut of the larvae and release toxins, thereby it. Similarly, Trichoderma are free living fungi. They live in the roots of higher plants and protect them from various pathogens. Baculoviruses is another bio-pesticides that is used as a biological control agent against insects and other arthropods.

MP Board Solutions

Question 11.
Three water samples namely river water, untreated sewage water and secondary effluent discharged from a sewage treatment plant were subjected to BOD test The samples were labelled A, B and C; but the laboratory attendant did not note which was which. The BOD values of the three samples A, B, and C were recorded as 20mg/L, 8 mg/L and400mg/L, respectively, which sample of the water is most polluted ? Can you assign the correct label to each assuming the river water is relatively clean ?
Answer:
The BOD values of the three samples A, B and C were recorded as 20 trig/L 8 mg/L and400mg/L.

Greater the BOD of waste water more is its polluting potential. So, sample C is more polluting as compared to sample A.

Hence, sample A is the secondary effluent, sample B is river water and sample C is untreated sewage water.

Question 12
Find out the name of microbes from which cyclosporine(animmuno-suppressive drug) and statins (blood cholesterol-lowering agents) are obtained.
Answer:

  • Cyclosporin A is produced by the fungus Trichoderma polysporum.
  • Statins are produced by die yeast Monascus purpureus which acts as a blood cholesterol-lowering agent.

Question 13.
Find out the role of microbes in die following and discuss it with your teacher,
(a) Single Cell Protein (SCP)
(b) Soil.
Answer:
(a) Single Cell Protein (SCP) refers to harmless microbial cells that can be used as an alternate source of good protein.

Just like mushrooms (a fungus) is eaten by many people and yeast is used by athletes as a protein source; similarly, other forms of microbial cells can also be used as food rich in protein, minerals, fats, carbohydrate and vitamins.

Microbes like SpiruMna and Methylophilus methylophus are being grown on an industrial scale on materials containing starch like waste water from potato processing plants, straw, molasses, animal manure and even sewage. These single cell microbes can be used as source of proteins.

(b) Microbes play an important role in organic farming which is done without the use of chemical fertilizers and pesticides. Bio-fertilizers are living organisms which help increase the fertility of soil. It involves the selection of beneficial microorganisms that help in improving plant growth through the supply of plant nutrients. Bio-fertilizers are introduced in seeds, roots or soil to mobilize the availability of nutrients. Thus, they are extremely beneficial in enriching the soil with organic nutrients.

Many species of bacteria and cyanobacteria have the ability to fix free atmospheric nitrogen, Rhizobium is a symbiotic bacteria found in the root nodules of leguminous plants. Azospirillium and Azotobocter are free living nitrogen fixing bacteria, whereas Anabena, Nostoc and Oscillitoria are examples of nitrogen-fixing cyanobacteria. Bio-fertilizers are cost effective and eco-freindly.

Microbes can also act as bio-pesticides to control insect pest in plants. An example of bio-pesticides is Bacillus thuringiensis, which produces a toxin that kills the insect pests. Dried bacterial spores are mixed in water and sprayed in agricultural fields. When larvae of insects feed on crops, these bacterial spores enter the gut of the larvae and release toxins, thereby it. Similarly, Trichoderma are free living fungi. They live in the roots of higher plants and protect them from various pathogens. Baculoviruses is another bio-pesticides that is used as a biological control agent against insects and other arthropods.

Question 14.
Arrange the following in the decreasing order (most important first) of their importance, for the welfare of human society. Give reasons for your answer. Biogas, Citric arid, Penicillin and Curd.
Answer:
The order of arrangement of products according to their decreasing importance is:
Penicillin—Biogas—Citric acid—Curd

Penicillin is the most important product for the welfare of human society. It is an antibiotic, which is used for controlling various bacterial diseases. The second most important product is biogas. It is an eco-friendly source of energy. The next important product is citric acid, which is used as a food preservative. The least important product is curd, a food item obtained by the action of lactobacillus bacteria on milk Hence, the products in the decreasing order of their importance are as follows:

Penicillin—Biogas—Citricacid—Curd.

Question 15.
How do biofertilizers enrich the fertility of the sofl?
Answer:
Bio-fertilizers are living orgainsms which help in increasing the fertility of soil. It involves the selection of beneficial microorganisms that help in improving plant growth through the supply of plant nutrients. These are introduced to seeds, roots, or soil to mobilize the availability of nutrients by their biological activity. Thus, they are extremely beneficial in enriching die soil with organic nutrients.

Many species of bacteria and cyanobacteria have the ability to fix free atmopheric nitrogen. Rhizobium is a symbiotic bacteria found in the root nodules of leguminous plants. Azospirillium and Azotobocter are free living nitrogen-fixing bacteria, whereas Anabena, Nostoc and Oscillitoriasie. examples of nitrogen-fixing cyanobacteria. Bio-fertilizers are cost effective and eco-friendly.

MP Board Solutions

Microbes in Human Welfare Other Important Questions And Answers

Microbes in Human Welfare Objective Type Questions

1. Choose the Correct answers:

Question 1.
A milk product which is sours as butter milk:
(a) Paneer
(b) Curd
(c) Yoghurt
(d) None of these.
Answer:
(b) Curd

Question 2.
Tetracydineisfoundin:
(a) From Strepto ramosus
(b) From Strepto oreofashion
(c) From Strepto freddy
(d) From Strepto nodosum.
Answer:
(a) From Strepto ramosus

Question 3.
Clostridium, Azotobacter, Rizobium increase the fertility through:
(a) From nitrogen fixation
(b) From denitrogenation
(c) From imulsification
(d) From vitamin.
Answer:
(a) From nitrogen fixation

Question 4.
The vitamin obtained from Streptomyces olivaceus and Bacillus megaterium:
(a) Vitamin C
(b) Vitamin D
(c) Vitamin E
(d) Vitamin B12
Answer:
(a) Vitamin C

Question 5.
Which of the following is used in the treatment of T.B. leprosy pneumonia:
(a) Bacteriophage
(b) Only virus
(c) Only bacteria
(d) Fungi.
Answer:
(d) Fungi.

Question 6.
How is virus used in biotechnology and microbiology:
(a) In form of medicine
(b) In form of vector
(c) In water treatment
(d) All of these.
Answer:
(b) In form of vector

Question 7.
Which of the following is usefuH in bakery product like Indian bread, biscuit and other product:
(a) Virus
(b) Bacteria
(c) Yeast
(d) Protozoan.
Answer:
(c) Yeast

Question 8.
Which vitamin is found in yeast:
(a) Vitamin C
(b) Vitamin D
(c) B complex
(d) Vitamin A.
Answer:
(c)B complex

Question 9.
Which medicine is obtained from Strepto ramosus:
(a) Terramycine
(b) Niomycine
(c) Erythomycine
(d) Actidine.
Answer:
(a) Terramycine

Question 10.
Nitrosomonas and Nitrobacter bacteria is:
(a) Denitrifying
(b) Nitrifying
(c) Azotobactor
(d) Haimoneproduces.
Answer:
(b) Nitrifying

Question 11.
Through lactic acid bacteria the transformation from milk to curd increases the amount of which vitamin:
(a) Vitamin C
(b) Vitamin D
(c) Vitamin B12
(d) Vitamin E.
Answer:
(c) Vitamin B12

Question 12.
Methanogen is not found in:
(a) Rhumen of cattles
(b) Biogas plant
(c) Bottom of paddy farm
(d) Cell wall of the bacteria.
Answer:
(d) Cell wall of the bacteria.

Question 13.
Water is free from this primary treatment of sewage:
(a) Dissolve impurities
(b) Suspended particle
(c) Harmfull substance
(d) Harmfull Bacteria.
Answer:
(b) Suspended particle

Question 14.
B.O.D. ofwaste water is calculated by:
(a) Total organic matter
(b) Bio-digradable organic matter
(c) Releasing of oxygen
(d) Consumption of oxygen.
Answer:
(d) Consumption of oxygen.

MP Board Solutions

Question 15.
Technique of biogas production in India developed by the help of these:
(a) Gas Authority of India V
(b) Oil and Natural Gas Aayog
(c) Indian Agricultural Statistics Research Institute.
(d) Indian Oil Corporation.
Answer:
(c) Indian Agricultural Statistics Research Institute.

Question 16.
Free living fungus Try coderma should be used in:
(a) Kill pests
(b) Biological control of plant diseases.
(c) In control of catterpillar of butterfly
(d) Formation of Antibiotics.
Answer:
(b) Biological control of plant diseases.

Question 17.
Mycorrhiza does not help the host plant in:
(a) Increasing the phosphorus capturing capacity in host plant
(b) Increasing dryness capturing capicity in host-plant
(c) Increase the immunity of root from pathogen
(d) Increase the immunity from insect in host-plant.
Answer:
(a) Increasing the phosphorus capturing capacity in host plant

2. Fill in the blanks:

  1. The branch of biology dealing with the structure and modes of existence of microscopic organisms is called ………………………
  2. The bacteria of …………………….. species is used by making paneer.
  3. Nitrosomonas and Nitrobacter is ……………………….. bacteria.
  4. ……………………. bacteria is used in vinegar industry.
  5. Pectinase enzyme is made by ……………………….. species.
  6. Size of microorganism is lesser than ……………………………. mm.
  7. Curd is made by …………………………… bacteria.
  8. By the adding of fruit or fruit essence into cheese which is made from milk. The substance is called ………………………..
  9. The curdled milk which is made from milk is called ………………………
  10. Antibiotics that are active chiefly against gram negative bacteria is called ………………………………

Answers:

  1. Microbiology
  2. Lactobacillus
  3. Nitrifying
  4. Acetobacteraceti
  5. Clostridium
  6. 0.1
  7. Lactobacillus
  8. Yoghurt
  9. Raw curded milk
  10. Polymyxin.

3. Match the Following:

MP Board Class 12th Biology Solutions Chapter 10 Microbes in Human Welfare 3
Answers:

  1. (d)
  2. (a)
  3. (b)
  4. (c)

MP Board Class 12th Biology Solutions Chapter 10 Microbes in Human Welfare 4
Answers:

  1. (c)
  2. (d)
  3. (e)
  4. (a)
  5. (b)

MP Board Class 12th Biology Solutions Chapter 10 Microbes in Human Welfare 5
Answers:

  1. (d)
  2. (a)
  3. (b)
  4. (c)

4. Answer in One Word/Sentence:

  1. Name the fish used to control mosquitoes.
  2. Name the two free living bacteria found in soil.
  3. What is called the control of insects and weeds ?
  4. Name symbiotic and non-symbiotic nitrogen fixing bacteria.
  5. Write full name of IPM.
  6. Give the name of one pesticide.
  7. How does biofertilizer act as fertilizer? (CBSE2004)
  8. What is yoghurt?
  9. What is sufu?
  10. Name the enzyme which is used to dissolve blood clot.
  11. What is interferon ?

Answers:

  1. Gambusia
  2. Azotobacter, Clostridium
  3. Pest control and weed control
  4. Rhizobium, Azotobacter
  5. Integrated pest management
  6. D.D.T.
  7. By nitrogen fixing
  8. Milk product
  9. Chinese food
  10. Streptokinase
  11. Antiviral protein

MP Board Solutions

Microbes in Human Welfare Very Short Answer Type Questions

Question 1.
Name useful microorganisms.
Answer:
Some useful microorganisms are bacteria, fungi and viruses.

Question 2.
Name the fungus which gave gibberellins hormone.
Answer:
Gibberellin is found by Gibberella fujikuroi.

Question3.
Which products are found by bacteria in dairy farms?
Answer:
Curd, paneer, butter, yoghurt, butter are milk are found in dairy farms in the help of Lactobacillus species and Streptococcus species.

Question 4.
Which microbes are gave antibiotics ?
Answer:
Generally bacteria and fungus gives us antibiotics.

Question 5.
What is microbiology ?
Answer:
The branch of science that deals with microorganisms.

Question 6.
Name the fungus which produce these products:

  1. Cytric acid,
  2. Vitamin B2

Answer:
MP Board Class 12th Biology Solutions Chapter 10 Microbes in Human Welfare 6

Question 7.
What is yoghurt ?
Answer:
Yoghurt is a semi-solid sourish food prepared from milk fermented by added bacteria.

Question 8.
Why does the river Ganga water not spoil even kept for long-time ?
Answer:
Bacteriophages are present in Ganga river’s water, they feed bacteria which are spoil water. So, this water does not spoil in long-time.

Question 9.
Who discover Penicilline ?
Answer:
Alexander Fleming.

Question 10.
Name the microorganism/fungi which gave penicillin.
Answer:
Penicillium notatum.

Question 11.
Which organism is used for making citric acid in industries ?
Answer:
Aspergillus niger.

Question 12.
Write the name of methanogen bacteria.
Answer:
Methano bacterium species.

Question 13.
What bacteria is found in anaerobic sludge.
Answer:
Methanogene.

Question 14.
What is lady bird ?
Answer:
It is an insect which is used as biocontroler for Aphid control.

Question 15.
What is the full form of IPM ?
Answer:
Integrated Pest Management.

Question 16.
Give the name of autotrophic nitrogen fixing microbes.
Answer:
Anabaena.

MP Board Solutions

Question 17.
Which mineral is absorbed by mycorhiza, this mineral is not should be absorbed by plant roots?
Answer:
Phosphorus.

Question 18.
Name the microorganism which is changed to milk in curd.
Answer:
Lactobacillus spp.

Question 19.
Which fungi is used in treatment of plant due to biological control ?
Answer:
Trichoderma spp.

Question 20.
Which bacteria is used in swiss paneer ?
Answer:
Propionibacterium shermanii.

Question 21.
Which paneer is completed by the growth of fungus?
Answer:
Roquefort cheese.

Question 22.
Name two alcoholic drink which is formed by without distillation.
Answer:
Bear and Wine.

Question 23.
Name two alcoholic drink which are formed by distillation.
Answer:
Whiskey and Rum.

Question 24.
What is the full form of BOD?
Answer:
Biochemical or Biological Oxygen Demand.

Question 25.
Name the bacteria which play an important role in N2 fixation in the soil.
Answer:
Spirullina.

Question 26.
Name an infectious agent which has neither DNA nor RNA.
Answer:
Prion.

MP Board Solutions

Microbes in Human Welfare Short Answer Type Questions

Question 1.
What is paneer ? Give its preparation method.
Answer:
Paneer is a milk product, which has 20-30% protein first filtered and the milk in thin cloth than heat on 60°C at 30 minutes and heat on 75°C at 15 second later it cold till 30°C. Add some quantity of lactic acid bacteria Streptococcus lactis, Streptococcus cremoris and enzyme renin. By this fat and casein protein is detached from milk after 45 minutes this mixture became solid. Now, they are cut into small pieces and boild in hot water, when it starts floating, they are separated and squeezed. Then they areput in salt water for treating. Paneer is now ready.

Question 2.
What is the utilization of Bacteria in agriculture ?
Answer:
Uses of Bacteria: Uses of bacteria for agriculture are as follows:

  1. They increase soil fertility due to decomposition of dead organisms.
  2. They increase soil fertility through nitrogen fixation in soil. ‘
  3. Green-blue algae is used the form of fertilizers.
  4. They are balance the quantity of mineral salts.

Question 3.
How are the bacteria used in vinegar industry ?
Answer:
Fermentation of sugar by yeast in vinegar industry. Due to this manner, wine is prepare. This ethyl alcohol abandoned in direct air for much time now, it is changed in vinegar.
MP Board Class 12th Biology Solutions Chapter 10 Microbes in Human Welfare 7

Question 4.
Name five fungi which are gave antibiotics.
Answer:
Name the fungi are as follows:
MP Board Class 12th Biology Solutions Chapter 10 Microbes in Human Welfare 8

Question 5.
Name five bacteria which produce antibiotics.
Answer:
Name the bacteria are as follows:
MP Board Class 12th Biology Solutions Chapter 10 Microbes in Human Welfare 9

MP Board Solutions

Microbes in Human Welfare Long Answer Type Questions

Question 1.
Write seven useful activities of Bacteria.
Answer:
Useful activities of bacteria:

1. N2 fixation : Some bacterias play an important role in nitrogen fixation e.g., Azotobacter, Clostridium, Rhizobium. These bacterias increase the fertility of soil by the fixation of atmospheric nitrogen.

2. Lactic acid synthesis: Lactobacillus lacti converts the milk sugar into lactic acid.

3. Acetic acid synthesis : Acetobacter aceti takes part in synthesis of acetic acid or vinegar.

4. Rating of fibres: Isolation of wood fibres from the stem of plants is called rating. Clostridium butyricum is used in rating of fibres.

5. Tobacco and Tea industry : Some bacteria like Micococcus candisens is used to increase the flavour of the leaves of tobacco and tea. This process is called as seasoning.

6. Medicine production: Bacteria are the chief source of antibiotics, hence, they are used to extract antibiotics, e.g., Streptomyces gresius (Streptomycine).

7. As symbionts: Bacteria presents in our body, helps in the various metabolic reactions e.g, E.coli.

Question 2.
Write economic importance of Fungi.
Answer:
Following are the economic importance of fungi:

1. As food : Mushrooms like Agaricus, Lycoperdon, Romaria, Clavasia are used as food. These mushrooms contain about 50% protein. Morchella is also used as food.

2. As medicine: Fungi provides various types of antibiotics as for example Penicillin, Griseofulvine, Citrinine, Clavicine, Gliotoxine, etc. Which are used in the treatment of disease.

3. Fertility of soil: Many fungi species increase the soil fertility by decomposition of dead organic matter.

4. Nitrogen fixation : Many fungus like Rhodotorula increases the soil fertility by nitrogen fixation.

5. In bakery industry : Yeast cells are used in bakery to produce spongy breads.

6. In wine industry : Yeast cells contain enzyme zymase which ferment sugar into alcohol.

7. In chemical industry : Many fungi species are used in the production of various types of acid like citric acid.

8. In cheese industry : Fungus Penicillium roqueforti is used in the preparation of camembert type of cheese from milk.

Question 3.
Explain the uses and types of virus.
Answer:
Uses of Viruses :

  • As it forms a link between non-living and living thus, it helps us to understand organic evolution.
  • Cyanophage (Blue-green algae viruses) are used to destroy blue-green algae grown in different areas.
  • Bacteriophages are used as biocides to destroy many harmful bacterias present in polluted area.

For example : Water of the river Ganga always remain pure and dean in bottles year after year due to presence of bacteriophage’ in it.
Nucleic acids of viruses: Viruses generally contain only one type of nucleic acid DNA or RNA. DNA is found in animal viruses, whereas RNA is found in plant viruses.
MP Board Class 12th Biology Solutions Chapter 10 Microbes in Human Welfare 10
Human Immuno Virus (HIV)
It causes AIDS disease in human. Full form of AIDS is Acquired Immuno Deficiency Syndrome. This virus destroys immune system of the body, thus, the patient of AIDS suffers from number of diseases at a time and at last he dies.
This virus is found surrounded by protein and a ring of RNA is found at the centre. Whole body of virus is surrounded by a covering of glycoprotein.
Type of Viruses: On the basis of host infected, viruses are grouped into following four groups :

  1. Animal viruses : Viruses which infect animals are called animal viruses. These viruses contain DNA as genetic material.
  2. Plant viruses: Viruses which infect plants are called plant viruses. These viruses contain RNA as genetic material.
  3. Cyanophages: Viruses that infect blue-green algae are called cyanophages. These viruses contain RNA as genetic material.
  4. Bacterial viruses or Bacteriophages : Viruses that infect bacteria are called as bacteriophages. They contain DNA as genetic materials.

MP Board Class 12th Biology Solutions