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Microbes in Human Welfare

Microbes in Human Welfare

Action PlanNotesQuestionsMock-Test
Study Action Plan (Sorted by Difficulty)
Bacillus thuringiensis and Bt Toxin
Accuracy: 50%
Total Attempted10
Total Correct5
Total Incorrect5
Difficulty Level:
Medium
Biochemical Oxygen Demand
Accuracy: 50%
Total Attempted4
Total Correct2
Total Incorrect2
Difficulty Level:
Medium
Biofertilisers and Organic Farming
Accuracy: 50%
Total Attempted10
Total Correct5
Total Incorrect5
Difficulty Level:
Medium
Methanogens in Rumen and Dung
Accuracy: 50%
Total Attempted2
Total Correct1
Total Incorrect1
Difficulty Level:
Medium
Diversity and Occurrence of Microbes
Accuracy: 60%
Total Attempted5
Total Correct3
Total Incorrect2
Difficulty Level:
Medium
Microbes in Sewage Treatment
Accuracy: 63%
Total Attempted19
Total Correct12
Total Incorrect7
Difficulty Level:
Medium
Bt Cotton
Accuracy: 67%
Total Attempted3
Total Correct2
Total Incorrect1
Difficulty Level:
Medium
Mycorrhiza and Glomus
Accuracy: 67%
Total Attempted9
Total Correct6
Total Incorrect3
Difficulty Level:
Medium
Secondary or Biological Treatment
Accuracy: 67%
Total Attempted9
Total Correct6
Total Incorrect3
Difficulty Level:
Medium
Baculoviruses and Nucleopolyhedrovirus
Accuracy: 73%
Total Attempted11
Total Correct8
Total Incorrect3
Difficulty Level:
Medium
Penicillin Discovery and Development
Accuracy: 75%
Total Attempted4
Total Correct3
Total Incorrect1
Difficulty Level:
Low
Fermented Dough: Idli, Dosa and Bread
Accuracy: 80%
Total Attempted5
Total Correct4
Total Incorrect1
Difficulty Level:
Low
Microbes in Production of Biogas
Accuracy: 80%
Total Attempted10
Total Correct8
Total Incorrect2
Difficulty Level:
Low
Organic Acids from Microbes
Accuracy: 80%
Total Attempted10
Total Correct8
Total Incorrect2
Difficulty Level:
Low
Sewage and Need for Treatment
Accuracy: 80%
Total Attempted5
Total Correct4
Total Incorrect1
Difficulty Level:
Low
Microbes in Industrial Products
Accuracy: 83%
Total Attempted29
Total Correct24
Total Incorrect5
Difficulty Level:
Low
Rhizobium in Legume Root Nodules
Accuracy: 83%
Total Attempted18
Total Correct15
Total Incorrect3
Difficulty Level:
Low
Microbes as Biofertilisers
Accuracy: 85%
Total Attempted20
Total Correct17
Total Incorrect3
Difficulty Level:
Low
Microbial Production of Chemicals and Enzymes
Accuracy: 88%
Total Attempted16
Total Correct14
Total Incorrect2
Difficulty Level:
Low
Cheese Production by Microbe
Accuracy: 91%
Total Attempted11
Total Correct10
Total Incorrect1
Difficulty Level:
Low
Antibiotics from Microbes
Accuracy: 93%
Total Attempted14
Total Correct13
Total Incorrect1
Difficulty Level:
Low
Microbes as Biocontrol Agents
Accuracy: 94%
Total Attempted32
Total Correct30
Total Incorrect2
Difficulty Level:
Low
Curd Formation by LAB
Accuracy: 100%
Total Attempted4
Total Correct4
Total Incorrect0
Difficulty Level:
Low
Cyanobacteria as Biofertilisers
Accuracy: 100%
Total Attempted1
Total Correct1
Total Incorrect0
Difficulty Level:
Low
Fermented Beverages
Accuracy: 100%
Total Attempted3
Total Correct3
Total Incorrect0
Difficulty Level:
Low
Free-Living Nitrogen Fixing Bacteria
Accuracy: 100%
Total Attempted3
Total Correct3
Total Incorrect0
Difficulty Level:
Low
Microbes in Household Products
Accuracy: 100%
Total Attempted11
Total Correct11
Total Incorrect0
Difficulty Level:
Low
Trichoderma as Biocontrol Fungus
Accuracy: 100%
Total Attempted6
Total Correct6
Total Incorrect0
Difficulty Level:
Low

Learning Objectives

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Learning Objectives

  • Identify the role of microbes in household products.
  • Discuss the importance of microbes in industrial products.
  • Explain the process of sewage treatment using microbes.
  • Describe the production of biogas and its significance.
  • Analyze the use of microbes as biocontrol agents in agriculture.
  • Evaluate the benefits of biofertilisers in soil fertility.

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Revision Notes & Summary

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Microbes in Human Welfare

8.1 Microbes in Household Products

  • Microbes are used in everyday products, such as curd from milk.
    • Lactic Acid Bacteria (LAB): Convert milk to curd, improving nutritional quality by increasing vitamin B12.
    • Fermentation: Used in making dough for foods like dosa and idli, producing CO₂ gas.

8.2 Microbes in Industrial Products

  • Microbes synthesize valuable products in industries, including beverages and antibiotics.
  • Industrial production requires large vessels called fermentors.

8.3 Microbes in Sewage Treatment

  • Microbes are used to treat sewage through activated sludge formation, recycling water in nature.

8.4 Microbes in Production of Biogas

  • Methanogens: Produce methane (biogas) while degrading plant waste, used as an energy source in rural areas.

8.5 Microbes as Biocontrol Agents

  • Biocontrol uses biological methods to manage pests and diseases, reducing reliance on harmful chemicals.

8.6 Microbes as Biofertilisers

  • Biofertilisers enrich soil nutrient quality, with sources including bacteria, fungi, and cyanobacteria.
    • Rhizobium: Fixes atmospheric nitrogen in leguminous plants.
    • Mycorrhiza: Fungi that enhance phosphorus absorption for plants.
    • Cyanobacteria: Fix nitrogen and add organic matter to soil.

Summary

  • Microbes play a crucial role in human welfare, with applications in food production, industrial processes, sewage treatment, energy production, pest control, and soil enrichment.
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Practice Test – MCQs, True/False

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Multiple Choice Questions

A.

Lactobacillus

B.

Azotobacter

C.

Saccharomyces cerevisiae

D.

Penicillium notatum
Correct Answer: B

Solution:

Azotobacter is a free-living nitrogen-fixing bacterium that can increase the nitrogen content of the soil naturally, making it beneficial for the farmer's purpose.

Chapter Concept:

Free-Living Nitrogen Fixing Bacteria

A.

Propionibacterium sharmanii; produces CO2CO_2

B.

Penicillium roqueforti; imparts flavor

C.

Saccharomyces cerevisiae; ferments lactose

D.

Lactobacillus; increases vitamin B12
Correct Answer: B

Solution:

Roquefort cheese is ripened by the fungus Penicillium roqueforti, which imparts a distinctive flavor to the cheese.

Chapter Concept:

Cheese Production by Microbe

A.

Lactobacillus

B.

Propionibacterium sharmanii

C.

Saccharomyces cerevisiae

D.

Bacillus thuringiensis
Correct Answer: B

Solution:

Propionibacterium sharmanii produces a large amount of CO2CO_2, which forms the characteristic large holes in Swiss cheese.

Chapter Concept:

Microbes in Household Products

A.

They are effective against a wide range of pests, including mammals.

B.

They are non-toxic to plants, mammals, birds, fish, and non-target insects.

C.

They enhance the growth rate of beneficial insects.

D.

They are used to increase the yield of crops directly.
Correct Answer: B

Solution:

Baculoviruses, especially Nucleopolyhedrovirus, are advantageous in pest control because they are non-toxic to non-target organisms, including plants, mammals, birds, fish, and beneficial insects.

Chapter Concept:

Baculoviruses and Nucleopolyhedrovirus

A.

Trichoderma species are used as chemical pesticides for controlling plant pathogens.

B.

Trichoderma species are free-living fungi that act as biocontrol agents against several plant pathogens in root ecosystems.

C.

Trichoderma species are used to enhance the growth of harmful bacteria in soil.

D.

Trichoderma species are primarily used in the production of alcoholic beverages.
Correct Answer: B

Solution:

Trichoderma species are free-living fungi commonly found in root ecosystems and are effective biocontrol agents against several plant pathogens, reducing the need for chemical pesticides.

Chapter Concept:

Trichoderma as Biocontrol Fungus

A.

Penicillin is used to treat viral infections such as the common cold.

B.

Penicillin is effective against bacterial infections like diphtheria and whooping cough.

C.

Penicillin is used as a preservative in food products.

D.

Penicillin is used to enhance the flavor of fermented dairy products.
Correct Answer: B

Solution:

Penicillin is an antibiotic effective against bacterial infections, such as diphtheria and whooping cough.

Chapter Concept:

Antibiotics from Microbes

A.

It produces antibiotics that kill all insects.

B.

It releases a toxin in the gut of caterpillars, killing them while leaving other insects unharmed.

C.

It enhances plant growth by fixing atmospheric nitrogen.

D.

It acts as a biofertilizer by decomposing organic matter.
Correct Answer: B

Solution:

Bacillus thuringiensis spores are sprayed on plants; larvae eat them, the toxin is released in the gut, and caterpillars die while other insects remain unharmed.

Chapter Concept:

Bacillus thuringiensis and Bt Toxin

A.

To fix atmospheric nitrogen

B.

To control soil-borne plant pathogens

C.

To produce ethanol

D.

To enhance plant growth by producing gibberellins
Correct Answer: B

Solution:

Trichoderma species are effective biocontrol agents against several plant pathogens, helping to control diseases in crops.

Chapter Concept:

Microbes as Biocontrol Agents

A.

Rhizobium

B.

Anabaena

C.

Azotobacter

D.

Saccharomyces cerevisiae
Correct Answer: B

Solution:

Anabaena is a cyanobacterium used as a biofertilizer in paddy fields due to its ability to fix atmospheric nitrogen.

Chapter Concept:

Microbes as Biofertilisers

A.

Deep inside thermal vents with temperatures around 100°C

B.

Under several meters of snow

C.

Highly acidic environments

D.

Surface of the moon
Correct Answer: D

Solution:

Microbes are known to thrive in extreme environments such as thermal vents, snow layers, and acidic environments. However, the surface of the moon lacks the necessary conditions like water and atmosphere to support microbial life.

Chapter Concept:

Diversity and Occurrence of Microbes

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Microbes in Human Welfare

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True or False

Correct Answer: True

Solution:

Bacillus thuringiensis (Bt) is a microbial biocontrol agent used to control butterfly caterpillars. It is applied to plants where the caterpillars ingest it, leading to their death.

Chapter Concept :

Microbes as Biocontrol Agents

Correct Answer: True

Solution:

Lactic acid bacteria (LAB) such as Lactobacillus grow in milk and produce acids that coagulate and partially digest the milk proteins, converting it into curd.

Chapter Concept :

Microbes in Household Products

Correct Answer: True

Solution:

Penicillin, discovered by Alexander Fleming, was the first antibiotic. Its effectiveness was later demonstrated by Chain and Florey, who were awarded the Nobel Prize for their work.

Chapter Concept :

Antibiotics from Microbes

Correct Answer: True

Solution:

Rhizobium bacteria form nodules on the roots of leguminous plants and fix atmospheric nitrogen into organic forms, enriching the soil.

Chapter Concept :

Microbes as Biofertilisers

Correct Answer: True

Solution:

Microbes are known to inhabit extreme environments, including thermal vents where temperatures can reach 100°C, as well as highly acidic environments.

Chapter Concept :

Diversity and Occurrence of Microbes

Correct Answer: True

Solution:

Aspergillus niger, a fungus, is indeed used for the industrial production of citric acid.

Chapter Concept :

Microbial Production of Chemicals and Enzymes

Correct Answer: True

Solution:

Lactic acid bacteria (LAB) such as Lactobacillus grow in milk and convert it into curd by producing acids that coagulate and partially digest milk proteins, thereby improving its nutritional quality.

Chapter Concept :

Microbes in Household Products

Correct Answer: True

Solution:

Methanobacterium is a methanogen that grows anaerobically on cellulosic material and produces methane, which is a major component of biogas.

Chapter Concept :

Microbes in Production of Biogas

Correct Answer: True

Solution:

Lactic acid bacteria not only convert milk into curd by coagulating milk proteins but also enhance its nutritional quality by increasing the vitamin B₁₂ content.

Chapter Concept :

Curd Formation by LAB

Correct Answer: True

Solution:

During secondary treatment, aerobic microbes grow into flocs and consume the organic matter in the effluent, thereby reducing its BOD.

Chapter Concept :

Microbes in Sewage Treatment

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