Microbes in Human Welfare for NEET UG
Most microbes are not germs: they make our curd, bread, antibiotics, biogas and biofertilisers, and clean our sewage. This chapter lists the useful microbes and what each does.
BiologyClass 1275 MCQs2 lessons13 flashcards4 memory tricks
Practise Microbes in Human Welfare free
What you'll learn
- Microbes in food, industry and medicine
Match microbes to the household and industrial products they make. - Sewage treatment, biogas and biofertilisers
Describe how microbes treat sewage, make biogas and enrich soil.
Memory tricks
Lactobacillus (LAB) turns milk into curd and adds vitamin B₁₂. Yeast (Saccharomyces) leavens bread and helps ferment idli/dosa batter. Propionibacterium makes the holes in Swiss cheese.
Streptokinase (Streptococcus): clot buster. Cyclosporin A (Trichoderma): suppresses rejection after transplants. Statins (Monascus): lower cholesterol. Penicillin (Penicillium): antibiotic.
Biochemical oxygen demand measures organic matter in water. Secondary sewage treatment lowers BOD; the sludge goes to anaerobic digesters that produce biogas.
Rhizobium: symbiotic nitrogen fixer in legume root nodules. Azotobacter and Azospirillum: free-living. Anabaena and Nostoc: cyanobacteria in paddy fields. Glomus: mycorrhiza that helps take up phosphorus.
Try 3 NEET-style questions
Q1. Baculoviruses used as narrow-spectrum biological control agents of insects belong mostly to the genus
- Bacillus (a bacterium)
- Trichoderma (a fungus)
- Rhizobium (a bacterium)
- Nucleopolyhedrovirus
Show answer
Answer: (4) Nucleopolyhedrovirus
Baculoviruses that attack insects and other arthropods mostly belong to the genus Nucleopolyhedrovirus. They are species-specific and have no negative effect on non-target organisms.
Q2. Biogas, rich in methane, is produced by
- Rhizobium in root nodules
- free-living Azotobacter
- Methanobacterium
- Nostoc in paddy fields
Show answer
Answer: (3) Methanobacterium
Methanogens such as Methanobacterium grow anaerobically on cellulosic material and produce methane, CO₂ and H₂.
Q3. Which alcoholic beverages are produced without distillation?
- Whisky and brandy
- Rum and whisky
- Wine and beer
- Brandy and rum
Show answer
Answer: (3) Wine and beer
Wine and beer are produced without distillation. Whisky, brandy and rum are produced by distilling the fermented broth.
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