Question
Microbiology Study Guide
1S. Which of the following refers to the lowest temperature that kills microbial cells in a broth in 10 minutes A. Thermal death point B. Decimal reduction time C. Thermal death time D. Microbial death rate E. CDC biosafety level 16. Most pathogens that infect human body are A. Psychrophiles B. Thermophiles C. Halophiles D. Mesophiles E. Hyperthermophiles 17. Which of the following is the most commonly used testing method in America for the evaluation of disinfectants and antiseptics? A. Phenol coefficient test B. Use-dilution test C. Kelsey-Sykes capacity test D. In-use test 18. Following is the list of chemical groups used to control microbes. The chemical often used to prepare the skin before surgery and treat burns belongs to the category of A. Phenolts B. Alcohols C. Halogens D. Gaseous agents E. Heavy metals 19. For years, people in eastern countries stored water in copper or brass (an alloy of copper and zinc) container. The belief was that it reduced the number of microbes in water and made it safer for consumption. To which of the following category of antimicrobial agents do copper and brass belong? A. Phenols B. Alcohols C. Halogens D. Gaseous agents E. Heavy metals 20. Which of the following are often used to sterilize plastic ware, mattresses, pillows and dried foods? A. Phenols B. Alcohols C. Halogens D. Gaseous agents E. Heavy metals 21. For testing the sensitivity of a microbe to a variety of chemical ager nts, zone of inhibition test is performed. Which of the following is NOT TRUE for this test? A. The chemical added on a paper disc diffuses into the medium. B. The diameter of the zone is measured as the reference. C. Larger the zone, the more resistant is the bacteria to the chemical D. The zone represents where there is no growth of the bacterium. E. The culture plate has to be incubated before observing the results.
Explanation / Answer
Que 15
Ans:
The following refers to the lowest temperature that kills microbial cells in a broth in 10 minutes: A. Thermal death point.
Explanation:
- Thermal death point is the lowest temperature that kills all of the micro-organisms present in liquid suspension i.e. broth in 10 minutes.
- Thermal death point is also denoted as TDP.
- Hence, correct option is: A. Thermal death point.