8. For the selection of endospore-forming bacteria, a mixed culture can be heated at
A.80°C for 10 minutes
B.70°C for 10 minutes
C.60°C for 10 minutes
D.90°C for 10 minutes
9. The concentration of agar to obtain semi solid media is
A.1.5-20%
B.0.5% or less
C.>10%
D.>10%but<20%
10. Which of the following bacteria dies quickly after drying?
A.Treponema pallidium
B.Mycobacterium tuberculosis
C.Staphylococcus aureus
D.Pseudomonas aeruginosa
11. Mac-Conkey medium is an example of
A.transport medium
B.enrichment medium
C.differential medium
D.all of these
12. Pseudomonas aeruginosa forms a blue water soluble pigment called
A.pyocyanin
B.chlororaphin
C.pyoverdin
D.β-carotene
13. Agar is used for solidifying culture media because
A.it does not affect by the growth of bacteria
B.it does not add to the nutritive properties of the medium
C.the melting and solidifying points of agar solution are not the same
D.all of the above
14. For the selection of lactobacilli present in cheddar cheese, the pH of the medium is maintained at
A.6.35
B.5.35
C.4.35
D.5.75
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