🦠 Microbiology Solved MCQs with Answers

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

1927 solved MCQs

Which of the following is sterilized with the help of glutaraldehyde?Answer: All of these The time in minutes at a specific temperature needed to kill a population of cells is theAnswer: F value Which of the following is a limitation of the autoclave?Answer: It will destroy heat labile materials Which of the following has most heat resistant spores?Answer: Bacillus stearothermophilus The lowest temperature that kills all microorganisms in a liquid suspension in 10 minutes is known as theAnswer: Thermal death point Which of the following tests is designed to simulate the natural conditions under which the disinfectants are used in hospitals?Answer: Capacity test Steam exposure of a material at 100°C for 20 minutes for three consecutive days is known asAnswer: Tyndallization Which of the following material is sterilized by use of red heat?Answer: Inoculating wires and loops Which of the following methods will not sterilize?Answer: 100°C boiling water for 30 minutes Which of the following is/are vapour-phase disinfectant/s?Answer: Both (a) and (b) Sweet and salty foods frequently don't require refrigeration to prevent spoilage because they haveAnswer: High concentration of solutes Iodophores are mixture ofAnswer: Iodine and surface active agents Which of the following compounds are commonly used as general antiseptics to treat cuts and scratches?Answer: Halogens Complete destruction of the microorganisms is commonly known asAnswer: Antisepsis In plant cells, which organelle performs photosynthesis and contains chlorophyll?Answer: Chloroplast The nonsymbiotic bacteria which fix nitrogen live in the soil independently areAnswer: All of these Nitrogen fixation by the microorganisms can be detected by adopting the approach ofAnswer: Both (a) and (b) Which of the following is not the biofertilisers producing bacteria?Answer: Clostridium Which of the following is capable of oxidizing sulfur to sulfates?Answer: Thiobacillus thiooxidans Most soil protozoa are flagellates or amoebas, having their dominant mode of nitrogen asAnswer: Ingestion of bacteria Which of the following microorganism use H₂S as the electron donor to reduce carbon dioxide?Answer: Both (a) and (b) Nitrifying bacteria can not be isolated directly by the usual techniques employed to isolate hetrotrophic bacteria. The reasons may be due toAnswer: slow growth Bacteria, as a group, are responsible forAnswer: All of these The phenomenon of commensalism refers to a relationship between organisms in whichAnswer: One species of a pair benefits The population of algae in soil is __________ that of either bacteria or fungi.Answer: Generally smaller than The transformation of nitrates to gaseous nitrogen is accomplished by microorganisms in a series of biochemical reactions. The process is known asAnswer: Denitrification Nitrogen fixation refers to the direct conversion of atmospheric nitrogen gas intoAnswer: Ammonia The diagnostic enzyme for denitrification isAnswer: Nitrate reductase A heterocyst isAnswer: A terminally differentiated cell that fixes nitrogen The groups of symbiotic bacteria, which have the ability to fix nitrogenAnswer: All of these