Microbes in Human Welfare: MCQ Test

1. Which of the following are considered major components of biological systems on Earth, alongside macroscopic plants and animals?

• Viruses only
• Protozoa and Fungi only
• Microbes
• Bacteria and Plants only

2. Microbes have been found to exist in extreme environments, such as deep inside geysers where the temperature may reach as high as:

• 50°C
• 80°C
• 100°C
• 150°C

3. Which of the following are examples of diverse microbes mentioned in the provided text?

• Protozoa
• Viroids
• Prions
• All of the above

4. What visible structures are formed when microbes like bacteria and many fungi are grown on nutritive media?

• Biofilms
• Mycelia
• Colonies
• Spores

5. Which group of micro-organisms is primarily responsible for converting milk into curd?

• *Saccharomyces cerevisiae*
• Lactic acid bacteria (LAB)
• *Propionibacterium sharmanii*
• *Acetobacter aceti*

6. Besides coagulation and partial digestion of milk proteins, how do lactic acid bacteria (LAB) improve the nutritional quality of curd?

• By increasing protein content
• By increasing vitamin B12
• By adding essential minerals
• By reducing lactose content

7. The puffed-up appearance of dough used for making foods like dosa and idli is attributed to the production of which gas during fermentation?

• Oxygen
• Nitrogen
• Carbon dioxide
• Methane

8. Which specific yeast is commonly known as 'baker’s yeast' and is used for fermenting dough in bread-making?

• *Monascus purpureus*
• *Trichoderma polysporum*
• *Saccharomyces cerevisiae*
• *Aspergillus niger*

9. The characteristic large holes in 'Swiss cheese' are a result of the extensive production of CO2 by which bacterium?

• *Lactobacillus*
• *Streptococcus*
• *Propionibacterium sharmanii*
• *Clostridium butylicum*

10. What specific microbial activity gives 'Roquefort cheese' its particular flavour?

• Specific bacterial fermentation
• Growing specific fungi on them
• A unique distillation process
• Addition of artificial flavourings

11. For the industrial-scale production of various valuable products, microbes are grown in very large vessels known as:

• Bioreactors
• Distillation columns
• Fermentors
• Digestion tanks

12. Among the following alcoholic beverages, which are produced *without* distillation?

• Wine and Whisky
• Beer and Rum
• Wine and Beer
• Brandy and Whisky

13. In the context of disease-causing organisms, the word 'antibiotics' literally means:

• For life
• Against life
• New life
• With life

14. Who is credited with the chance discovery of the first antibiotic, Penicillin?

• Ernest Chain
• Howard Florey
• Alexander Fleming
• Louis Pasteur

15. Penicillin was named after the mould *Penicillium notatum*, which Alexander Fleming observed inhibiting the growth of what bacteria?

• *Streptococcus*
• *Lactobacillus*
• *Staphylococci*
• *Acetobacter aceti*

16. Which scientists were jointly awarded the Nobel Prize in 1945 for their contributions to the discovery and establishment of Penicillin's full potential as an effective antibiotic?

• Alexander Fleming and Louis Pasteur
• Ernest Chain and Howard Florey
• Alexander Fleming, Ernest Chain, and Howard Florey
• Louis Pasteur and Robert Koch

17. Which of the following deadly diseases, previously causing millions of deaths, have antibiotics significantly helped in treating?

• Plague
• Whooping cough (kali khansi)
• Diphtheria (gal ghotu)
• Leprosy (kusht rog)
• All of the above

18. Which fungus is used for the commercial and industrial production of citric acid?

• *Saccharomyces cerevisiae*
• *Aspergillus niger*
• *Trichoderma polysporum*
• *Monascus purpureus*

19. Which bacterium is responsible for the production of acetic acid?

• *Lactobacillus*
• *Acetobacter aceti*
• *Clostridium butylicum*
• *Propionibacterium sharmanii*

20. The bacterium *Clostridium butylicum* is known for commercially producing which organic acid?

• Citric acid
• Lactic acid
• Butyric acid
• Acetic acid