🦠 Microbiology Solved MCQs with Answers

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

1927 solved MCQs

Nitrogen oxidation (nitrification)refers to theAnswer: Conversion of ammonium ions into nitrates through the activities of certain bacteria. An example of a symbiotic nitrogen fixer isAnswer: Rhizobium Which of the following is correct?Answer: All of the above In the process of nitrogen fixation, which of the following microorganism is involved?Answer: Non symbiotic and symbiotic microorganisms only Which of the following statement is not true about composition of biogas?Answer: It also contains with traces of O₂ and Cl₂ The physical structure of soil is improved by the accumulation ofAnswer: Mold mycelium __________ play a key role in the transformation of rock to soil.Answer: Cyanobacteia The groups of bacteria which have the ability to fix nitrogen from air to soil areAnswer: Both (a) and (b) The nitrogenase consists ofAnswer: Both (a) and (b) The crops which are involved in nitrogen fixation areAnswer: All of these Denitrification may be distinguished asAnswer: Both (a) and (b) The conversion of molecular nitrogen into ammonia is known asAnswer: Nitrogen fixation The breakdown of cattle manure in biogas is accomplished by which of the following type of bacteria?Answer: All of these Which of the following species of different genera of bacteria are not capable of transforming nitrate to nitrogen?Answer: None of these Some microorganisms have the ability to increase the nitrogen content of soils, are called asAnswer: Nitrogen fixation Nitrogen fixationAnswer: Both (a) and (b) For rapid decomposition by microbes, the substrate should have a C/N ratio ofAnswer: 30-40 Which are the main source of biofertilisers?Answer: Cyanobacteria The organisms responsible for the characteristic musty or earth odor of a freshly plowed field is/areAnswer: All of the above Denitrification isAnswer: Both (a) and (b) Degree of compost maturity can be assesed byAnswer: Both (a) and (b) The energy value of biogas is typicallyAnswer: 400-700 BTU/ft³ The microbial ecosystem of soil includesAnswer: Biotic and abiotic components of soil Denitrification is carried outAnswer: All of the above Which of the following soil microorganism is involved in the reduction of sulfates to H₂S?Answer: Desulfotomaculum The diagnostic enzyme for nitrogen-fixing organisms isAnswer: Nitrogenase Which of the following fungi on infecting crop roots can improve their uptake of phosphorus and other nutrients?Answer: VA Mycorrhiza Syntrophism involvesAnswer: Exchange of nutrients between two species Assimilative denitrification is done byAnswer: All of the above Genetic variations areAnswer: Stable