Chapter 4: Sterilization — Online MCQ Test
MICROBIOLOGY · CLASS 11th · Tamil Nadu State Board
Practice Chapter 4: Sterilization with a free chapter-wise online MCQ test.
This chapter covers: Focusing on microbial control this chapter covers physical agents heat filtration radiation and chemical disinfectants. Students analyze sterilization mechanics autoclaving hot air....
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 4: Sterilization — Important Questions & Answers
What is the process of completely destroying or removing all forms of microbial life, including spores?
- A. Disinfection
- B. Sterilization
- C. Sanitization
- D. Antisepsis
Answer: B. Sterilization
Sterilization is the total destruction of all microorganisms including highly resistant bacterial endospores.
Sterilization is the total destruction of all microorganisms including highly resistant bacterial endospores.
Which of the following is an example of a physical method of sterilization?
- A. Phenolics
- B. Autoclaving
- C. Ethylene oxide
- D. Halogens
Answer: B. Autoclaving
Autoclaving uses steam under pressure, which is a physical method involving thermal control.
Autoclaving uses steam under pressure, which is a physical method involving thermal control.
Which of the following organisms is often used as a biological indicator to test autoclave efficiency?
- A. Bacillus subtilis
- B. Geobacillus stearothermophilus
- C. Escherichia coli
- D. Staphylococcus aureus
Answer: B. Geobacillus stearothermophilus
Geobacillus stearothermophilus spores are highly heat resistant and are the gold standard for autoclave validation.
Geobacillus stearothermophilus spores are highly heat resistant and are the gold standard for autoclave validation.
If you are comparing an autoclave and a hot air oven, which statement is true?
- A. Autoclave uses dry heat, oven uses moist heat.
- B. Oven requires higher temperatures (160-180°C) for a longer time than the autoclave.
- C. Both require identical holding times.
- D. Autoclave is safer for dry powders.
Answer: B. Oven requires higher temperatures (160-180°C) for a longer time than the autoclave.
Dry heat (oven) is less penetrative than moist heat (autoclave), thus requiring higher temperatures and longer durations.
Dry heat (oven) is less penetrative than moist heat (autoclave), thus requiring higher temperatures and longer durations.
Why is the use of 'autoclave tape' alone insufficient to prove that items are sterile?
- A. The tape is too expensive.
- B. It only indicates that the specific temperature was reached, not the duration or pressure required for sterilization.
- C. The tape changes color due to humidity only.
- D. Bacteria can survive on the tape.
Answer: B. It only indicates that the specific temperature was reached, not the duration or pressure required for sterilization.
Autoclave tape is a chemical indicator of temperature only; biological indicators are required to confirm the killing of resistant spores.
Autoclave tape is a chemical indicator of temperature only; biological indicators are required to confirm the killing of resistant spores.