Q. To select cholera-causing bacterium, Vibrio cholerae, the pH of the medium is maintained at a pH of 8.58.906.793.5 Answer: 8.5

Q. Which of the following chemotherapeutic agents may affect the growth of Campylobacter jejuni? VacomycinPolymyxinTrimethoprimNone of these Answer: None of these

Q. The solidifying agent commonly used in preparation of media is/are agarsilica gelboth (1) and (2)none of these Answer: both (1) and (2)

Q. In the process of freeze drying, a dense cell suspension is placed in small vials and is frozen at -60 to -78°C-20 to -30°C-30 to -48°C-48 to -58°C Answer: -60 to -78°C

Q. Which of the following is used for the proper maintenance and preservation of pure cultures? Periodic transfer to fresh mediaPreservation by overlaying cultures with mineral oilPreservation by lyophilizationAll of the above Answer: All of the above

Q. Cell size and cell number can be measured using hemocytometercoulter counterpetroff-hausser counting chambernone of these Answer: coulter counter

Q. Which of the following bacteria can grow in acidic pH? Vibrio choleraeLactobacilliShigellaSalmonella Answer: Lactobacilli

Q. Treponema sp. can be selected by taking advantage of ____________ small cell sizemotilitydilute mediasmall cell diameter and bacterial motility Answer: small cell diameter and bacterial motility

Q. Disease-producing species occurring in a mixed culture can be selected by taking advantage of _________ its pathogenic propertiesspecial carbon sourcespecial nitrogen sourcetoxic chemicals Answer: its pathogenic properties

Q. Vibrio cholerae can grow in a medium with a pH of _______ 5.57.08.52.0 Answer: 8.5

Q. In physical method of selection, endospore-forming bacteria can be obtained by heating the mixed culture to _____________ 70 degree C for 10 minutes80 degree C for 10 minutes60 degree C for 10 minutes90 degree C for 10 minutes Answer: 80 degree C for 10 minutes

Q. Which of the following is not a physical method for selection of pure culture? Heat treatmentpH of the mediaCell size and motilityUse of dilute media Answer: Use of dilute media