This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Biology Chapter 10 Microbes In Human Welfare – Quiz 3 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Biology Chapter 10 Microbes In Human Welfare Quiz 3 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. ..... serve as an important bio-fertilizer in paddy fields. A) Cyanobacteria. B) Azotobacter. C) Methanobacterium. D) Mycorrhiza. Show Answer Correct Answer: A) Cyanobacteria. 2. Which step of sewage treatment involves "Sequential Filtration and Sedimentation" ? A) Primary Treatment. B) Secondary Treatment. C) Biological Treatment. D) Tertiary Treatment. Show Answer Correct Answer: A) Primary Treatment. 3. Which of the following can be used as a biocontrol agent in the treatment of plant disease? A) Trichoderma. B) Chlorella. C) Anabaena. D) Lactobacillus. Show Answer Correct Answer: A) Trichoderma. 4. Which one of the following alcoholic drink is produced without distillation? A) Rum. B) Brandy. C) Wine. D) Whisky. Show Answer Correct Answer: C) Wine. 5. Alexander Fleming discovered Penicillin while working on: A) Penicillium notatum. B) Staphylococci bacteria. C) Streptococcus bacteria. D) E. coli. Show Answer Correct Answer: B) Staphylococci bacteria. 6. Big holes in Swiss cheese are made by a: A) A machine. B) A bacterium that produces methane gas. C) A bacterium producing a large amount of carbon dioxide. D) A fungus that releases a lot of gases during its metabolic activitie. Show Answer Correct Answer: C) A bacterium producing a large amount of carbon dioxide. 7. Methanobacterium is found in: A) Anaerobic sludge and Rumen of cattle. B) Aeration tank and Rumen of cattle. C) Activated sludge and Rumen of cattle. D) River water and Rumen of cattle. Show Answer Correct Answer: A) Anaerobic sludge and Rumen of cattle. 8. Acinetobacter baumannii is a ..... A) Decomposing bacteria. B) Pathogenic bacteria. C) Nitrogen-fixing bacteria. D) None of the above. Show Answer Correct Answer: B) Pathogenic bacteria. 9. The significance of Flocs in secondary Treatment is not A) Consumption of organic matter. B) Reduction of BOD. C) Reduction in polluting potential. D) Reduction of inorganic salts. Show Answer Correct Answer: D) Reduction of inorganic salts. 10. What is produced in the digesters? A) Methane gas. B) Chlorine. C) Fertilizer. D) Effluent. Show Answer Correct Answer: A) Methane gas. 11. Streptokinase is isolated from A) Streptococcus bacteria. B) Staphylococcus bacteria. C) Saccharomyces Yeast. D) None of the above. Show Answer Correct Answer: A) Streptococcus bacteria. 12. Which characteristic makes Nucleopolyhedrovirus an excellent candidate for Integrated Pest Management (IPM)? A) Broad spectrum insecticidal applications. B) Species-specific, narrow spectrum insecticidal applications. C) Ability to harm birds and mammals to reduce competition. D) Persistence in the environment for decades. Show Answer Correct Answer: B) Species-specific, narrow spectrum insecticidal applications. 13. In anaerobic sludge digesters, the anaerobic bacteria A) Digest Fungi. B) Digest Bacteria. C) Both A and B. D) Digest the organic matter. Show Answer Correct Answer: C) Both A and B. 14. After the clarification step in wastewater treatment, the solid waste called ..... is sold off and the liquid waste called ..... moves on the be filtered and disinfected A) Sewage and dirty water. B) Sludge and effluent. C) Effluent and slude. D) Dirty water and sewage. Show Answer Correct Answer: B) Sludge and effluent. 15. Agriculture by using only biofertilizers is called A) Manuring. B) Composting. C) Inorganic farming. D) Organic farming. Show Answer Correct Answer: D) Organic farming. 16. Which of the following is a commercial blood cholesterol lowering agent? A) Cyclosporin A. B) Statin. C) Streptokinase. D) Lipases. Show Answer Correct Answer: B) Statin. 17. An organism used as a biofertiliser for soyabean crop is A) Azotobacter. B) Azopirillum. C) Rhizobium. D) Nostoc. Show Answer Correct Answer: C) Rhizobium. 18. Statins act by: A) Competitively inhibiting the enzyme for cholesterol synthesis. B) Non-competitively inhibiting the enzyme for cholesterol synthesis. C) Increasing cholesterol degradation. D) Preventing cholesterol absorption. Show Answer Correct Answer: A) Competitively inhibiting the enzyme for cholesterol synthesis. 19. Types of alcoholic beverages obtained depend on- A) Raw materials used for fermentation. B) Types of processing. C) Both a and b. D) Type of storage pattern. Show Answer Correct Answer: C) Both a and b. 20. A good producer of citric acid is A) Aspergillus. B) Pseudomonas. C) Clostridium. D) Saccharomyces. Show Answer Correct Answer: A) Aspergillus. 21. What is the role of bacteria present in the rumen of cattle? A) Production of methane. B) Regulation of digestion. C) Breakdown of cellulose. D) Synthesis of polysaccharides. Show Answer Correct Answer: C) Breakdown of cellulose. 22. The gases that evolve from anaerobic sludge digester constitute ..... A) Natural gas. B) Biogas. C) Water gas. D) None of these. Show Answer Correct Answer: B) Biogas. 23. Microbes are present everywhere. Which of the following is an environment where microbes can exist? A) Deep inside the geysers (thermal vents) where temperature is 100$^\circ$C. B) Deep in the soil and under layers of snow. C) In highly acidic environments. D) All of the above. Show Answer Correct Answer: D) All of the above. 24. Which of the following is a symbiotic nitrogen fixer? A) Azospirillum. B) Azotobacter. C) Rhizobium. D) Oscillatoria. Show Answer Correct Answer: C) Rhizobium. 25. ..... are free living bacteria which fix atmospheric nitrogen in soil. A) Azobacterium. B) Acetobacterium. C) Azotobacter. D) Azabacterium. Show Answer Correct Answer: C) Azotobacter. ← PreviousNext →Related QuizzesClass 12 Biology Chapter 10 Microbes In Human Welfare Quiz 1Class 12 Biology Chapter 10 Microbes In Human Welfare Quiz 2Class 12 Biology Chapter 10 Microbes In Human Welfare Quiz 4Class 12 Biology Chapter 10 Microbes In Human Welfare Quiz 5Class 12 Biology Chapter 10 Microbes In Human Welfare Quiz 6Class 12 Biology Chapter 10 Microbes In Human Welfare Quiz 7Class 12 Biology Chapter 10 Microbes In Human Welfare Quiz 8Class 12 Biology Chapter 10 Microbes In Human Welfare Quiz 9Class 12 Biology Chapter 10 Microbes In Human Welfare Quiz 10Class 12 Biology Chapter 10 Microbes In Human Welfare Quiz 11 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books