🦠 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 word cell was first used byAnswer: Robert Hooke What are Blue-Green bacteria called?Answer: Cyanobacteria The endosymbiosis hypothesis provides an explanation for howAnswer: eukaryotes developed from prokayotes The Archaea include all of the following exceptAnswer: cyanobacteria The gram-negative organisms isAnswer: None of these Catalase production is negative in which of the following?Answer: Streptococcus Which of the following is a substitute for crystal violet used in gram-staining procedure?Answer: Methylene blue Which of the following inference(s) indicate(s) the ability of an organism to utilize citrate as a sole source of carbon in Simmon's citrate medium?Answer: Both (a) and (b) The organisms that can be acid-fast stained isAnswer: all of these The primary stain of Gram's method isAnswer: crystal violet At what concentration of sulphuric acid, Nocardia resists decolourization?Answer: 0.5% sulphuric acid Which of the following is commonly used as Gram's decolouriser?Answer: A mixture of ethyl alcohol and acetone Production of acetoin can be detected by which of the following tests?Answer: Voges-Proskauer test The production of sufficient acid by fermentation of glucose leads to decrease in pH such that pH of the medium falls below 4.5. Which of the following test can detect it?Answer: Methyl red test What is the colour of gram -postive bacteria on a gram staining?Answer: Purple What is the colour of gram-negative bacteria on a gram staining?Answer: Pink Which of the following is a primary stain for acid fast staining of mycobacteria?Answer: Carbol fuchsin The deinococci are gram-positive cocci and rods that are distinctive in their unusually great resistance toAnswer: both (a) and (b) Which of the following shows a positive urease test?Answer: Both (a) and (b) Which of the following(s) is/ are oxidase-positive bacteria?Answer: All of these What is the order of reagents used in the Gram stain?Answer: Crystal violet, iodine, decolorizer, safranin Gram staining was developed accidentally in 1884 byAnswer: Hans Christian Gram Which of the following organisms can be demonstrated with silver impregnation method?Answer: Spirochaetes Which of the following(s) show(s) positive results for phenylalanine deaminase test?Answer: All of these The process of Gram staining is based on the ability of bacterial cell wallAnswer: to retain the crystal violet dye during solvent treatment. Which of the following bacteria lack a cell wall and are therefore resistant to penicillin?Answer: Mycoplasmas A cluster of polar flagella is calledAnswer: lophotrichous Flagella move the cell byAnswer: spinning like a propeller The protein from which hook and filaments of flagella are composed of, isAnswer: flagellin The cooci which mostly occur in single or pairs areAnswer: Diplococci