🦠 Microbiology Solved MCQs with Answers

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

1927 solved MCQs

Organisms, using organic compounds as electron donors are calledAnswer: organotrophs The reproduction by budding occur inAnswer: Both (a) and (b) Starvation proteins are produced by a culture during which of the following segments of the growth curve?Answer: Stationary phase The cell reproduction in bacteria may occur byAnswer: all of these During exponential growth, the growth rate isAnswer: reciprocal of generation time A spore differs from an actively replicating bacterium in that the sporeAnswer: all of the above Which of the following has more tolerance for acidic pH (lower pH)?Answer: Yeast and moulds The ability of Vibrio fischeri to produce bioluminescence chemicals only when a certain population density has been reached is an example ofAnswer: quorum sensing Antimicrobial constituents for the microbial growth in foods areAnswer: intrinsic factor The average size of cells during the exponential phase of growth isAnswer: lesser than the lag phase A culture broth tube was very turbid at the surface but clear throughout the rest of the tube indicating that theAnswer: organism are aerobes A synergistic effect is observed whenAnswer: all of the above Generation time isAnswer: both (a) and (c) The term facultative anaerobe refers to an organism thatAnswer: uses oxygen when present or grows without oxygen when absent The microorganisms that grow best in a low-oxygen environment is called a (n)Answer: microaerophile Pseudomonas pseudoflava can grow asAnswer: both (a) and (b) Which of the following is the suitable temperature range for mesophiles?Answer: 25-40°C Exponential phase of growth curve of bacteria is of limited duration because ofAnswer: all of these A culture broth tube was very turbid at the bottom of the tube but clear at the top of the tube indicating that theAnswer: organism cannot produce superoxide dismutase and/or catalase In the exponential phase, the cells and cell massAnswer: double at a constant rate What is the primary source of food for marine life?Answer: Phytoplankton Postgates assay technique is useful in determining if a cell is viable even though it isAnswer: incapable of cell division What are the extrinsic factors for the microbial growth?Answer: all of these Quantitative measurement of bacterial growth can be carried out by measuringAnswer: all of these Organisms such as lactobacilli that have elaborate requirements for specific nutrients i.e. vitamins and other growth promoting substances, are generally called asAnswer: fastidious hetrotrophs The combination of low levels of NaCl, NaNO3 (sodium nitrate), and slightly acid pH can prevent multiplication and toxin formation ofAnswer: all of these Bacteria of genusNitrosomonas use __________ as their electron source.Answer: ammonia The generation time of a culture that produces two generations per hour isAnswer: greater than that produces three generations per hour Autotrophic bacteria are those whichAnswer: make their own food Which of the following organisms typically get their carbon for biosynthesis from organic compounds?Answer: Aerobic, glucose-respiring bacteria (aerobic respiration)