This quiz works best with JavaScript enabled. Home > Cbse > Class 12 > Science > Biology > Class 12 Biology Chapter 10 Microbes In Human Welfare – Quiz 4 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Biology Chapter 10 Microbes In Human Welfare Quiz 4 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Which of the following is NOT a benefit of Mycorrhiza (Glomus) to the plant? A) Absorption of phosphorus. B) Resistance to root-borne pathogens. C) Tolerance to salinity and drought. D) Direct killing of insect pests. Show Answer Correct Answer: D) Direct killing of insect pests. 2. Identify the microbe used for the commercial production of Ethanol: A) Aspergillus niger. B) Lactobacillus. C) Clostridium butylicum. D) Saccharomyces cerevisiae. Show Answer Correct Answer: D) Saccharomyces cerevisiae. 3. Which one is produced from germinated Barley malt grain? A) Whisky. B) Red wine. C) Beer. D) Rum. Show Answer Correct Answer: C) Beer. 4. The bacteria commonly found in the, anaerobic sludge during sewage treatment: A) Zymomonas mobilis. B) Methanogens. C) Thermoanaerobacter ethanolics. D) Streptococcus. Show Answer Correct Answer: B) Methanogens. 5. Examples of antibiotics: A) Penicillin. B) Tetracyclines. C) Neomycin. D) All of the above. Show Answer Correct Answer: D) All of the above. 6. Bacillus thuringiensis is widely used as: A) Insecticide. B) Weedicides. C) Rodenticide. D) None of the above. Show Answer Correct Answer: A) Insecticide. 7. Treatment of waste water is done by the heterotrophic microbes naturally present in the sewage. This treatment is carried out in: A) One stage (Chemical only). B) Two stages (Physical and Biological). C) Three stages (Physical, Chemical, Biological). D) Two stages (Anaerobic only). Show Answer Correct Answer: C) Three stages (Physical, Chemical, Biological). 8. Apart from anaerobic sludge, Methanogens are also found in: A) The rumen of cattle. B) The stomach of humans. C) Root nodules. D) Aerated water. Show Answer Correct Answer: A) The rumen of cattle. 9. Trichoderma polysporum is used to produce A) Pectinases. B) Statins. C) Cyclosporin A. D) Lipases. Show Answer Correct Answer: C) Cyclosporin A. 10. Which of the following options includes biofertilizers? A) Cowdung manure and farmyard waste. B) A quick growing crop ploughed back into the field. C) Nostoc, Oscillatoria. D) All of these. Show Answer Correct Answer: C) Nostoc, Oscillatoria. 11. Which of the following bacteria convert milk into curd? A) Streptococcus. B) Bacillus. C) Propionibacterium. D) Lactobacillus. Show Answer Correct Answer: D) Lactobacillus. 12. Acetobacter aceti is the producer of Acetic acid. It belongs to which group of microbes? A) Bacteria. B) Virus. C) Fungi. D) Yeast. Show Answer Correct Answer: A) Bacteria. 13. Vinegar is prepared from alcohol with the help of A) Acrtobacter. B) Rhizobium. C) Lactobacillus. D) Azotobacter. Show Answer Correct Answer: A) Acrtobacter. 14. Agriculture by using only bio fertilizer is A) Manuring. B) Composting. C) Organic farming. D) Inorganic farming. Show Answer Correct Answer: C) Organic farming. 15. Assertion (A):Disadvantages of synthetic pesticides can be overcome by the use of natural or biopesticidesReason(R):Biopesticides are harmless agents which are used to control weeds and pest without damage. A) Both A and R are true and R is the correct explanation of A. B) Both A and R are true But R is not correct explanation of A. C) A is true, but R is false. D) Both A and R are false. Show Answer Correct Answer: B) Both A and R are true But R is not correct explanation of A. 16. Citric acid is produced by Aspergillus niger, which is a: A) Bacterium. B) Fungus. C) Protozoan. D) Yeast. Show Answer Correct Answer: B) Fungus. 17. Which industrial products are synthesized from microbes?A. AntibioticsB. Fermented beveragesC. Enzymes and chemicalsD. Bioactive molecules A) A, B, C. B) A, B, C, D. C) A, C. D) A, C, D. Show Answer Correct Answer: B) A, B, C, D. 18. Antibiotics will only kill ..... A) Viruses. B) Bacteria. C) Fungus. D) None of the above. Show Answer Correct Answer: B) Bacteria. 19. Which are examples of fungi? A) Mold. B) Yeast. C) Mushrooms. D) All of the above. Show Answer Correct Answer: D) All of the above. 20. State the function of cyclosporin A A) Removal of clots from blood vessels. B) Lowering of blood cholesterol. C) Immuno-suppressive agent. D) Removal of oil stains. Show Answer Correct Answer: C) Immuno-suppressive agent. 21. Example of a natural insect repellant A) Citronella oil. B) Coconut oil. C) Linseed oil. D) None of the above. Show Answer Correct Answer: A) Citronella oil. 22. Streptomycin is produced from- A) Streptomyces fradiae. B) Streptomyces venezuellae. C) Streptomyces scoleus. D) Streptomyces griseus. Show Answer Correct Answer: D) Streptomyces griseus. 23. What gases are produced in anaerobic sludge digesters? A) Methane and CO$_{2}$ only. B) Methane, Hydrogen sulphide and CO$_{2}$. C) Methane, hydrogen sulphide and O$_{2}$. D) Hydrogen sulphide and CO$_{2}$. Show Answer Correct Answer: B) Methane, Hydrogen sulphide and CO$_{2}$. 24. Which of the following organisms is used in the production of beverages? A) Saccharomyces cerevisiae. B) Aspergillus niger. C) Clostridium butylicum. D) Penicillium notatum. Show Answer Correct Answer: A) Saccharomyces cerevisiae. 25. ..... is a pigment that gives a pinkish hue to rhizobium induced root nodules. A) Leghaemoglobin. B) Carotenoid. C) Mauveine. D) None of the above. Show Answer Correct Answer: A) Leghaemoglobin. 26. The oily stains from laundry can be removed by A) Endonuclease. B) Esterase. C) Ligases. D) Lipases. Show Answer Correct Answer: D) Lipases. 27. Gases produced in anaerobic sludge digestors are A) Methane, oxygen and hydrogen sulphide. B) Hydrogen sulphide, methane and sulphur dioxide. C) Hydrogen sulphide, nitrogen and methane. D) Methane, Hydrogen Sulphide and CO2. Show Answer Correct Answer: D) Methane, Hydrogen Sulphide and CO2. 28. Fungi are important to an ecosystem as A) Controllers. B) Regulators. C) Decomposers. D) Producers. Show Answer Correct Answer: C) Decomposers. 29. In primary treatment, all solids that settle form the ..... , and the supernatant forms the ..... A) Tertiary sludge; Effluent. B) Primary effluent; Secondary sludge. C) Primary sludge; Effluent. D) Secondary sludge; Effluent. Show Answer Correct Answer: C) Primary sludge; Effluent. 30. BOD stands for Biochemical Oxygen Demand. A high BOD value in a water sample indicates: A) The water is pure. B) High polluting potential. C) Low polluting potential. D) Low organic matter content. Show Answer Correct Answer: B) High polluting potential. 31. Which of the following is not involved in nitrogen fixation? A) Oscillatoria. B) Anabena. C) Nostoc. D) Pseudomonas. E) Azetobacter. Show Answer Correct Answer: D) Pseudomonas. 32. Which of the following is the pair of biofertilizers? A) Anabaena and Azotobacter. B) Nostoc and legume. C) Rhizobium and grasses. D) Salmonella & E. coli. Show Answer Correct Answer: A) Anabaena and Azotobacter. 33. Microbes are present in-A. SoilB. AirC. WaterD. Thermal springs A) A, B. B) A, C, D. C) C, D. D) A, B, C, D. Show Answer Correct Answer: D) A, B, C, D. 34. The large holes in 'Swiss cheese' are due to production of a large amount of CO ..... 2 by a: A) Yeast named Saccharomyces cerevisiae. B) Bacterium named Lactobacillus. C) Fungus named Penicillium roqueforti. D) Bacterium named Propionibacterium sharmanii. Show Answer Correct Answer: D) Bacterium named Propionibacterium sharmanii. 35. Alexander Fleming was working on A) Salmonella. B) Penicillin notatum. C) Streptococcus. D) Staphylococci. Show Answer Correct Answer: D) Staphylococci. 36. High biological oxygen demand in a water body means ..... A) Water is not polluted. B) Waterbody contains lots of lifeforms. C) Waterbody is suitable for animals to live in. D) Water is polluted. Show Answer Correct Answer: D) Water is polluted. 37. The primary treatment of waste water involves the removal of: A) Toxic substances. B) Stable particles. C) Harmful bacteria. D) Dissolved impurities. Show Answer Correct Answer: B) Stable particles. 38. How is bacteria helpful? A) Provide Nitrogen dioxide, food products, environmental recycling, medicine. B) Provide oxygen, food products, environmental recycling, medicine. C) Provide oxygen, food wastes, environmental recycling, medicine. D) Provide oxygen, food products, environment medicine. Show Answer Correct Answer: B) Provide oxygen, food products, environmental recycling, medicine. 39. A bacterial infection ..... be treated using an antibiotic. A viral infection ..... A) Can; also can. B) Can; cannot. C) Cannot; can. D) Cannot; also cannot. Show Answer Correct Answer: B) Can; cannot. 40. Lactic Acid Bacteria grow in A) Juice. B) Milk. C) Water. D) Curd. Show Answer Correct Answer: B) Milk. 41. Which of the following sets of alcoholic beverages are produced by distillation of the fermented broth? A) Wine and Beer. B) Whisky, Brandy and Rum. C) Wine, Whisky and Brandy. D) Beer, Rum and Vodka. Show Answer Correct Answer: B) Whisky, Brandy and Rum. 42. The guts of various ruminants contain ..... A) Acidophiles. B) Halophiles. C) Methanogens. D) All of the above. Show Answer Correct Answer: C) Methanogens. 43. The flavour in yogurt is due to A) CH3COOH. B) CH3CHO. C) CH2CH2. D) CH3COCH3. Show Answer Correct Answer: B) CH3CHO. 44. The large vessels for growing microbes on an industrial scale are called A) Biogas vessel. B) Petri dish. C) Digestors. D) Fermentors. Show Answer Correct Answer: D) Fermentors. 45. Besides macroscopic plants and animals, microbes are the major components of biological systems on this earth. Microbes are present: A) Only in soil and water. B) Only in living organisms. C) Everywhere-soil, water, air, inside our bodies and that of other plants and animals. D) Only in extreme environments. Show Answer Correct Answer: C) Everywhere-soil, water, air, inside our bodies and that of other plants and animals. 46. A nitrogen fixing microbe associated with the fern Azolla in rice fields is A) Anabaena. B) Spirulina. C) Rhizobium. D) Rankia. Show Answer Correct Answer: A) Anabaena. 47. Which of these processes does not give off CO2? A) Lactate fermentation. B) Aerobic respiration. C) Alcoholic fermentation. D) None of the above. Show Answer Correct Answer: B) Aerobic respiration. 48. The bacterium that commonly lives in animal and human intestines is- A) Corynebacterium. B) Vibrio cholerae. C) Bacillus anthraces. D) Escherichia coli. Show Answer Correct Answer: D) Escherichia coli. 49. Microbes can survive in extreme environments such as thermal vents where the temperature may be as high as: A) 100$^\circ$C. B) 40$^\circ$C. C) 50$^\circ$C. D) 80$^\circ$C. Show Answer Correct Answer: A) 100$^\circ$C. 50. Bacillus thuringiensis is used to control: A) Bacterial infections. B) Weed growth. C) Fungal diseases. D) Insect pests. Show Answer Correct Answer: D) Insect pests. 51. How do Statins lower blood cholesterol? A) By competitively inhibiting the enzyme responsible for synthesis of cholesterol. B) By increasing the excretion of cholesterol. C) By preventing the absorption of cholesterol in the intestine. D) By breaking down cholesterol in the blood. Show Answer Correct Answer: A) By competitively inhibiting the enzyme responsible for synthesis of cholesterol. 52. ..... and ..... bacteria can fix atmospheric nitrogen while free living in the soil. A) Lactobacillus. B) Azospirillum and Azotobacter. C) Streptococcus and staphylococcus. D) Cyanobacteria and Nostoc. Show Answer Correct Answer: B) Azospirillum and Azotobacter. 53. Identify the bacteria that can fix atmospheric nitrogen while living freely in the soil: A) Rhizobium and Glomus. B) Azospirillum and Azotobacter. C) Nostoc and Glomus. D) Rhizobium and Azospirillum. Show Answer Correct Answer: B) Azospirillum and Azotobacter. 54. Which is useful to remove the oily stains in laundry A) Renin. B) Protease. C) Lipase. D) Amylase. Show Answer Correct Answer: C) Lipase. 55. Which one of the following is not a bio fertilizer A) Nostoc. B) Mycorrhiza. C) Rhizobium. D) Agrobacterium. Show Answer Correct Answer: D) Agrobacterium. 56. Which of the following is used in organ transplant patients? A) Pectinase. B) Streptokinase. C) Cyclosporin A. D) Statins. Show Answer Correct Answer: C) Cyclosporin A. 57. Match the Microbe with the Organic Acid it produces:(A) Aspergillus niger, (B) Acetobacter aceti, (C) Clostridium butylicum, (D) Lactobacillus (i) Lactic acid, (ii) Butyric acid, (iii) Citric acid, (iv) Acetic acid A) A-iii, B-iv, C-ii, D-i. B) A-iv, B-iii, C-ii, D-i. C) A-ii, B-iv, C-iii, D-i. D) A-iii, B-ii, C-iv, D-i. Show Answer Correct Answer: A) A-iii, B-iv, C-ii, D-i. 58. Biogas can be good substitute for A) Fuel wood. B) Coal. C) Charcoal. D) Oil and petrol. Show Answer Correct Answer: A) Fuel wood. 59. The chemical substances produced by some microbes which can kill or retard the growth of other microbes are called- A) Toddy. B) Antibiotics. C) Ethanol. D) Lactic acid. Show Answer Correct Answer: B) Antibiotics. 60. How are the spores of Bacillus thuringiensis applied by farmers? A) Injected into the plant stem. B) Mixed with water and sprayed onto vulnerable plants like brassicas and fruit trees. C) Mixed with soil near the roots. D) Released as adult flies. Show Answer Correct Answer: B) Mixed with water and sprayed onto vulnerable plants like brassicas and fruit trees. ← PreviousNext →Related QuizzesScience QuizzesClass 12 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 3Class 12 Biology Chapter 10 Microbes In Human Welfare Quiz 5Class 12 Biology Chapter 1 Reproduction In Organisms QuizClass 12 Biology Chapter 11 Biotechnology Principles And Processes QuizClass 12 Biology Chapter 12 Biotechnology And Its Applications QuizClass 12 Biology Chapter 13 Organisms And Populations Quiz 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books