MCQs Based on Microbiology & Sterilization for ICAR (SRF or JRF) /ASRB /CSIR NET/BET Exams #1

 

1. The primary use of Koch's postulates is to:
   (A) Clearly identify and characterize a particular microorganism
   (B) Isolate microorganisms from diseased animals
   (C) Demonstrate that a disease is caused by a microorganism
   (D) Develop vaccines for specific diseases

2. Which of the following is NOT part of Koch's postulates?
   (A) The microorganism is never found in healthy animals
   (B) The microorganism is always found in diseased animals
   (C) The microorganism must cause disease in healthy animals
   (D) The microorganism must secrete a toxin in culture

3. Which of the following induces dimerisation of thymine?
   (A) X-rays (B) U.V. rays (C) α-rays (D) None of these

4. Which of the following is ionizing radiation?
   (A) U.V. rays (B) IR (C) β-rays (D) None of these

5. Thermal death time is:
   (A) Time required to kill all cells at a given temperature
   (B) Temperature that kills all cells in a given time
   (C) Time and temperature needed to kill all cells
   (D) All of the above

6. Which of the following method of sterilization has no effect on spores?
   (A) Drying (B) Hot air oven (C) Autoclave (D) None of these

7. Discontinuous heating is called:
   (A) Pasteurization (B) Sterilization (C) Fermentation (D) Tyndallisation

8. Autoclaving is carried out at:
   (A) Dry heat (B) Atmospheric pressure (C) 121°C (D) All of these

9. Temperature used for hot air oven is:
   (A) 100°C for 1 hour (B) 120°C for 1 hour (C) 160°C for 1 hour (D) 60°C for 1 hour

10. Temperature in pasteurization is:
    (A) 62.8°C (B) 35.7°C (C) 68.2°C (D) 60.8°C

11. The condition required for autoclave:
    (A) 121°C temp. and 15 lbs. pressure for 20 min
    (B) 120°C temp. and 20 lbs. pressure for 30 min
    (C) 150°C temp. for 1 hr
    (D) 130°C temp. for 2 hr

12. Glassware are sterilized by:
    (A) Autoclaving (B) Hot air oven (C) Incineration (D) None of these

13. By pasteurization:
    (A) All the microorganisms can be removed
    (B) Only pathogenic forms can be removed
    (C) Only non-pathogenic forms can be removed
    (D) All of these are correct

14. Spores are killed by:
    (A) 70% alcohol (B) Glutaraldehyde (C) Autoclaving (D) Both B and C