43. Quantitative measurement of bacterial growth can be carried out by measuring
A.cell count
B.cell mass
C.cell activity
D.all of these

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44. Organisms such as lactobacilli that have elaborate requirements for specific nutrients i.e. vitamins and other growth promoting substances, are generally called as
A.fastidious hetrotrophs
B.chemo-lithotrophs
C.chemotrophs
D.photo-organotrophs

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45. The combination of low levels of NaCl, NaNO3 (sodium nitrate), and slightly acid pH can prevent multiplication and toxin formation of
A.Salmonella
B.S. aureus
C.C. botulinum
D.all of these

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46. Bacteria of genus Nitrosomonas use __________ as their electron source.
A.ammonia
B.H2S
C.succinate
D.light

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47. All organisms require at least small amounts of carbondioxide, However, some can use CO2 as their sole source of carbon. Such organisms are termed as
A.autotrophs
B.phototrophs
C.chemotrophs
D.photo-organotrophs

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48. The generation time of a culture that produces two generations per hour is
A.greater than that produces three generations per hour
B.lesser than that produces three generations per hour
C.equal to that produces three generations per hour
D.none of the above

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49. Autotrophic bacteria are those which
A.make their own food
B.form a long chain glycocalyx
C.are highly susceptible to penicillin
D.produce a blue-green pigment

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