8. In viruses with envelopes
A.the envelope and the embedded proteins are encoded by the viral nucleic acid
B.the envelope is derived from the host but it contains embedded proteins coded by the viral nucleic acid
C.the envelope is coded by the viral nucleic acids, but the proteins come from the host's membrane proteins
D.the envelope and its imbedded proteins are derived from the host's membranes

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9.  Which of the following bacteria can be typed by phage typing method?
A.Staphylococcus aureus
B.Salmonella typhi
C.Vibrio cholerae
D.All of these

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10.  __________ protein keeps the prophage dormant and prevents virus reproduction.
A.Operator
B.Promotor
C.Repressor
D.Enhancer

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11.  __________ is specifically able to have a long-term relationship with the host known as lysogeny.
A.Temperate virus
B.Adsorbed virus
C.RNA phage
D.DNA phage

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12. Which of the following properties is due to lysogenic conversion by phages?
A.Toxin production in Corynebacterium diphtheriae
B.Toxin production in Clostridium botulinum types C and D
C.Antigenic variation in Salmonella anatum
D.All of the above

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13. T-even phage binding to E. coli probably involves
A.electrostatic interaction
B.hydrophobic interaction
C.covalent bonds
D.all of these

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14. The filamentous bacteriopohage infect male E. coli cells by attaching to
A.lipopolysaccharide
B.the cell wall
C.the tip of the pilus
D.the cell membrane

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