🦠 Microbiology Solved MCQs with Answers

Practice 1927 approved 🦠 Microbiology questions with verified answers from the 🧬 Medical Science subject for Pakistan exams.

1927 solved MCQs

The time required to kill 90% of the microorganisms in a sample at a specific temperature is theAnswer: D value Which of the following is best used for long term storage of microbial samples when carried out properly?Answer: Storage in a freezer at ultra low temperatures (-70°C) Which of the following is not a disinfectant containing a heavy metal?Answer: Chlorine Which is the most important surface active disinfectants?Answer: Cationic compounds Which disinfectant would be most effective against Staphylococcus found in a blood spill?Answer: None of these Which of the following substances can sterilize?Answer: Ethylene oxide Milk is pasteurized in batch method by keeping it atAnswer: 63°C for 30 minutes Preservation of foods by using salts and sugars works byAnswer: Creating a hypertonic environment Which of the following items could be sterilized by dry heat sterilization?Answer: Glass pipettes Which of the following does not kill endospores?Answer: Pasteurization Which disinfectant was the most effective against Salmonella"?Answer: Merthiolate If a canning procedure is not properly followed, which type of microbe is most likely to grow in the canned food?Answer: Obligate Anaerobe Bactericidal concentration of phenol isAnswer: 1% Which of the following is most effective for sterilizing mattresses and plastic petri plates?Answer: Ethylene oxide Which of the following skin disinfectant(s) is/are most frequently used?Answer: Both (a) and (b) All of the following are sporicidal exceptAnswer: Alcohol Which of the following describes the effect of ionizing radiation on microbes?Answer: Induces electrons and protons to jump out of the molecules of the microbe The process of making an object free from living organisms including bacterial and fungal spores and viruses is known asAnswer: Sterilization Media containing spores and thermolabile constituents are sterilized byAnswer: UV radiation A(n)____is used to prevent infection by killing or inhibiting pathogen growth on animal tissues.Answer: Antiseptic One drawback to the use of ultraviolet light as a sterilizing agent is itsAnswer: Failure to kill microbes located in the center of an object Ethylene oxide is used to destroy or kill which of the following microbes?Answer: All of these Which of the following was the first widely used antiseptic and disinfectant?Answer: Phenol If a 1:600 dilution of a test compound kills a standard population of Staphylococcus aureus in 10 minutes but not 5 minutes while a 1:60 dilution of phenol kills the population in the same time, what is the phenol coefficient of the test compound?Answer: 10 Microbes can be removed from a liquid solution by the process ofAnswer: Filtration Which of the following is bactericidal?Answer: Ionizing radiation Which of the following process can be efficiently carried out by incineration?Answer: Destruction of contaminated materials The organisms retained in the fluids filtered by Seitz filter isAnswer: None of these Which of the following material is sterilized by heating at 160°C in a hot air oven for one hour?Answer: All of these For sterilization of which material gamma rays can be used?Answer: None of these