Class 12 Biology - TELANGANA
Microbes in Human Welfare
The chapter 'Microbes in Human Welfare' in Class 12 Biology explores how microorganisms like bacteria, fungi, and viruses are not just agents of disease, but are immensely beneficial to human life. Students will study the role of microbes in household food production like curd and bread, industrial production of beverages and antibiotics, sewage treatment plants for pollution control, and as eco-friendly biofertilisers and biocontrol agents. This chapter is vital for the Telangana (TSBSE) board exams as it is a high-scoring, fact-based unit that frequently features direct questions, diagrams of biogas plants, and applications of biotechnology.
Start Learning FreeKey Concepts
Microbes in Household Products
Lactic Acid Bacteria (LAB) convert milk to curd, improving its nutritional quality by increasing Vitamin B12, while Saccharomyces cerevisiae (brewer's yeast) is used to ferment dough for idli, dosa, and bread.
Microbes in Industrial Products
Microorganisms are grown in large vessels called fermentors to produce beverages like wine and beer using yeast, and life-saving antibiotics such as penicillin derived from the fungus Penicillium notatum.
Microbes in Sewage Treatment
Secondary treatment of wastewater relies on aerobic microbes (flocs) to consume organic matter, followed by anaerobic sludge digesters that produce inflammable biogas like methane, hydrogen, and carbon dioxide.
Microbes as Biocontrol Agents
Biological control involves using natural predators and pathogens, such as the bacterium Bacillus thuringiensis (Bt), to manage butterfly caterpillars and other pests without harmful chemical pesticides.
Microbes as Biofertilisers
Organisms like Rhizobium in legume root nodules, free-living Azospirillum, and Mycorrhiza fungi enrich soil nutrients by fixing atmospheric nitrogen and absorbing phosphorus.
Important Formulas
Board Exam Info
In the Telangana (TSBSE) Class 12 Biology board examination, this chapter typically carries around 4 to 6 marks. Questions usually include Very Short Answer Questions (VSAQs) worth 2 marks on specific scientific names (e.g., source of cyclosporin A or statins) and Short Answer Questions (SAQs) worth 4 marks explaining sewage treatment or biogas plant construction.
Frequently Asked Questions
What is the difference between primary and secondary sewage treatment?
Primary treatment is a physical process involving the removal of large and small particles through filtration and sedimentation. Secondary treatment is a biological process where aerobic and anaerobic microbes break down the organic matter in the effluent.
How does Lactobacillus improve the nutritional quality of milk?
Lactic Acid Bacteria (LAB) multiply in milk and convert it into curd by producing acids that coagulate and partially digest milk proteins. During this process, they also significantly increase the amount of Vitamin B12 in the curd.
What are statins and which microbe produces them?
Statins are blood-cholesterol lowering agents that act by competitively inhibiting the enzyme responsible for synthesis of cholesterol. They are commercially produced by the yeast Monascus purpureus.
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