Part 8: Mixed & Advanced MCQs – NEET Style (25 Questions)
Part 8: Mixed & Advanced MCQs – NEET Style (25 Questions)
Q176. Which one is correctly matched?
a) Aspergillus niger – lactic acid
b) Acetobacter aceti – acetic acid
c) Saccharomyces – citric acid
d) Lactobacillus – butyric acid
Answer: b
- b) Correct: Acetobacter aceti → acetic acid (vinegar).
Q177. Antibiotics are mostly obtained from:
a) Archaea
b) Cyanobacteria
c) Actinomycetes and fungi
d) Protozoa
Answer: c
- c) Correct: Antibiotics → actinomycetes (Streptomyces) and fungi (Penicillium).
Q178. In BOD measurement, high BOD indicates:
a) Clean water
b) High pollution and organic matter
c) Absence of microbes
d) Low microbial activity
Answer: b
- b) Correct: High BOD = polluted water.
Q179. Which of the following is NOT a biofertilizer?
a) Azolla
b) Anabaena
c) Nostoc
d) Salmonella
Answer: d
- d) Correct: Salmonella = pathogen, not a biofertilizer.
Q180. The role of leghemoglobin in root nodules is to:
a) Transport nitrogen
b) Regulate oxygen supply for nitrogenase
c) Fix carbon dioxide
d) Produce ATP
Answer: b
- b) Correct: Leghemoglobin binds O₂ → protects nitrogenase.
Q181. Biogas production involves:
a) Aerobic bacteria
b) Anaerobic methanogens
c) Cyanobacteria
d) Actinomycetes
Answer: b
- b) Correct: Methanogens → anaerobic digestion.
Q182. Which one is used as biocontrol agent in agriculture?
a) Trichoderma
b) Bt toxin
c) Baculovirus
d) All of the above
Answer: d
- d) Correct: All are biocontrol agents.
Q183. Bt toxin gene inserted in cotton produces resistance against:
a) Stem borers
b) Bollworms
c) Aphids
d) Caterpillars of silkworm
Answer: b
- b) Correct: Bt cotton → resistant to bollworm.
Q184. Which fungus produces cyclosporin A?
a) Penicillium notatum
b) Trichoderma polysporum
c) Aspergillus niger
d) Monascus purpureus
Answer: b
- b) Correct: Trichoderma polysporum → Cyclosporin A.
Q185. Statins are used to:
a) Reduce blood pressure
b) Lower cholesterol levels
c) Kill bacteria
d) Kill fungi
Answer: b
- b) Correct: Statins inhibit cholesterol synthesis.
Q186. Which of the following is mismatched?
a) Penicillin – fungus
b) Streptomycin – Streptomyces
c) Cyclosporin – actinomycete
d) Statins – Monascus
Answer: c
- c) Correct: Cyclosporin comes from fungus (Trichoderma), not actinomycete.
Q187. Which one is NOT a use of microbes?
a) Cheese production
b) Production of vaccines
c) Antibiotic synthesis
d) Formation of plastics
Answer: d
- d) Correct: Plastics are not produced by microbes (except bioplastics like PHB, not in NCERT).
Q188. Flocs in sewage treatment consist of:
a) Protozoa only
b) Fungi + bacteria
c) Viruses + algae
d) Sand particles
Answer: b
- b) Correct: Bacteria + fungi (flocs).
Q189. In which industry is Aspergillus niger used?
a) Acetic acid production
b) Citric acid production
c) Butyric acid production
d) Antibiotics
Answer: b
- b) Correct: A. niger → citric acid.
Q190. The production of Swiss cheese is due to:
a) Lactobacillus
b) Propionibacterium shermanii
c) Rhizopus
d) Saccharomyces
Answer: b
- b) Correct: CO₂ from Propionibacterium → holes in Swiss cheese.
Q191. Which is true for antibiotics?
a) They are specific against viruses
b) They are produced by microbes to kill/inhibit other microbes
c) They are vaccines
d) They improve photosynthesis
Answer: b
- b) Correct: Antibiotics target bacteria/microbes, not viruses.
Q192. Which cyanobacterium is used in rice fields as biofertilizer?
a) Nostoc
b) Oscillatoria
c) Anabaena
d) All of the above
Answer: d
- d) Correct: All fix nitrogen in paddy fields.
Q193. Which antibiotic is used in typhoid treatment?
a) Chloramphenicol
b) Rifampicin
c) Penicillin
d) Vancomycin
Answer: a
- a) Correct: Chloramphenicol → typhoid.
Q194. Septic tanks act as:
a) Primary treatment only
b) Secondary (anaerobic digestion)
c) Tertiary treatment
d) Filtration units
Answer: b
- b) Correct: Septic tanks = anaerobic secondary treatment.
Q195. In integrated pest management (IPM), the emphasis is on:
a) Only chemical pesticides
b) Only biological methods
c) Biocontrol + minimal chemical use
d) Genetic engineering only
Answer: c
- c) Correct: IPM balances biocontrol and minimal pesticides.
Q196. Which organism is used in the production of beer and wine?
a) Lactobacillus
b) Saccharomyces cerevisiae
c) Aspergillus
d) Rhizopus
Answer: b
- b) Correct: Yeast → alcohol fermentation.
Q197. Which component of biogas is flammable?
a) CO₂
b) Methane
c) H₂S
d) Nitrogen
Answer: b
- b) Correct: Methane is the combustible component.
Q198. Mycorrhiza is an example of:
a) Fungal parasitism
b) Fungal mutualism with roots
c) Bacterial disease
d) Viral association
Answer: b
- b) Correct: Fungus + plant roots = mutualistic association.
Q199. Which antibiotic was discovered by Selman Waksman?
a) Penicillin
b) Streptomycin
c) Chloramphenicol
d) Rifampicin
Answer: b
- b) Correct: Streptomycin → Selman Waksman.
Q200. Which one is INCORRECT about microbes in human welfare?
a) Used in sewage treatment
b) Used in biofertilizers
c) Used in antibiotics
d) Always harmful to humans
Answer: d
- d) Correct: Microbes are mostly beneficial in industry, food, agriculture; only some are harmful.
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