8. Which of the following is commonly used as Gram's decolouriser?
A.Ethyl alcohol
B.Methyl alcohol
C.Acetone
D.A mixture of ethyl alcohol and acetone

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9. Production of acetoin can be detected by which of the following tests?
A.Citrate test
B.Voges-Proskauer test
C.Methyl red test
D.Indole test

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10. 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?
A.Indole test
B.Methyl red test
C.Citrate utilization test
D.Voges-Proskauer test

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11. What is the colour of gram -postive bacteria on a gram staining?
A.Purple
B.Pink
C.Colourless
D.Green

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12. What is the colour of gram-negative bacteria on a gram staining?
A.Purple
B.Pink
C.Green
D.Colourless

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13. Which of the following is a primary stain for acid fast staining of mycobacteria?
A.Crystal violet
B.Carbol fuchsin
C.Geimsa
D.Methylene blue

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14.  The deinococci are gram-positive cocci and rods that are distinctive in their unusually great resistance to
A.radiation
B.desiccation
C.both (a) and (b)
D.extreme temperatures

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