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Chapter Analysis
Intermediate11 pages • EnglishQuick Summary
The chapter 'Microbes in Human Welfare' explores the diverse roles of microbes in household products, industrial processes, sewage treatment, production of biogas, biocontrol agents, and biofertilisers. It discusses how microbes are utilized in daily life for fermenting and creating various foods and drinks, and producing antibiotics. The chapter also covers the environmental benefits of using microbes for sewage treatment and biofertilisation, thus reducing pollution and dependence on chemical inputs.
Key Topics
- •Microbes in Household Products
- •Microbes in Industrial Processes
- •Sewage Treatment by Microbes
- •Biogas Production
- •Biocontrol Agents
- •Biofertilisers
- •Microbes in Fermentation
- •Role of Microbes in Biochemical Cycles
Learning Objectives
- ✓Understand the diverse roles of microbes in daily life and industry.
- ✓Explain how microbes contribute to environmental sustainability.
- ✓Analyze the benefits of biocontrol over chemical pesticides.
- ✓Recognize the importance of biofertilisers in agriculture.
- ✓Learn the processes of microbial sewage treatment and biogas production.
- ✓Appreciate the historical impact of microbial antibiotics on human health.
Questions in Chapter
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 with the help of a microscope, which sample would you carry and why?
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Give examples to prove that microbes release gases during metabolism.
Page 159
In which food would you find lactic acid bacteria? Mention some of their useful applications.
Page 159
Name some traditional Indian foods made of wheat, rice and Bengal gram (or their products) which involve use of microbes.
Page 159
In which way have microbes played a major role in controlling diseases caused by harmful bacteria?
Page 159
Name any two species of fungus, which are used in the production of the antibiotics.
Page 160
What is sewage? In which way can sewage be harmful to us?
Page 160
What is the key difference between primary and secondary sewage treatment?
Page 160
Do you think microbes can also be used as source of energy? If yes, how?
Page 160
Microbes can be used to decrease the use of chemical fertilisers and pesticides. Explain how this can be accomplished.
Page 160
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, 8mg/L and 400mg/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?
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Find out the name of the microbes from which Cyclosporin A (an immunosuppressive drug) and Statins (blood cholesterol lowering agents) are obtained.
Page 160
Find out the role of microbes in the following and discuss it with your teacher. (a) Single cell protein (SCP) (b) Soil
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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 acid, Penicillin and Curd
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How do biofertilisers enrich the fertility of the soil?
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Additional Practice Questions
Explain how the production of lactic acid by bacteria can be useful in household products.
easyAnswer: Lactic acid bacteria (LAB) help convert milk to curd, enhancing nutritional value by increasing vitamin B12. They also impart unique flavors to dairy products and improve gut health.
Discuss the role of microorganisms in the industrial production of ethanol.
mediumAnswer: Saccharomyces cerevisiae, or brewer's yeast, is used to ferment sugars from cereals and fruits, producing ethanol. This process is fundamental in making beverages like beer and wine.
Describe the process of sewage treatment using microbes.
mediumAnswer: Sewage treatment involves primary treatment for physical removal of solids, followed by secondary treatment where aerobic microbes decompose organic matter, reducing the BOD and treating the waste water effectively.
How do biocontrol agents offer advantages over chemical pesticides?
hardAnswer: Biocontrol agents, unlike chemical pesticides, target specific pests without harming useful species or the environment, reducing chemical residues and supporting biodiversity.
Evaluate the importance of biofertilisers in sustainable agriculture.
mediumAnswer: Biofertilisers, sourced from bacteria and fungi, enrich soil nutrients and enhance plant growth without the side effects of chemical fertilisers, promoting soil health and sustainability.
What are the advantages of using biogas as a renewable energy source?
easyAnswer: Biogas, produced from microbial digestion of organic waste, is renewable, reduces reliance on fossil fuels, lowers methane emissions from waste, and can be used for cooking and lighting, particularly in rural areas.
Illustrate the symbiotic relationship between mycorrhizal fungi and plants.
mediumAnswer: Mycorrhizal fungi enhance plant nutrient uptake, particularly phosphorus, in exchange for carbohydrates from the plant, improving plant resilience and growth.
Discuss the impact of antibiotics derived from microbes on human health.
hardAnswer: Microbial antibiotics like Penicillin revolutionized medicine by effectively treating bacterial infections, saving countless lives, although overuse has led to resistance issues.
Analyze the role of microbes in cheese production.
mediumAnswer: Microbes ferment milk sugars into lactic acid, leading to curdling and flavor development, while specific bacteria give distinct textures and flavors to cheeses like Swiss and Roquefort.