50.  Cyanobacteria have
A.a gram-positive cell wall
B.a gram-negative cell wall
C.Neither (a) nor (b)
D.No cell wall

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51. In which of the following, lipo-polysaccharide is a major constituent of outer membrane of the cellwall?
A.Gram-positive bacteria
B.Gram-negative bacteria
C.Fungi
D.None of these

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52. Which of the following structure(s) is /are external to cell wall?
A.Flagella
B.Stalks
C.Sheath
D.All of these

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53. Which of the following may be most likely to be missing from a gram-positive bacterium?
A.Penicillin binding protein
B.Peptidoglycan
C.Lipopolysaccharide
D.Phospholipid bilayer membrane

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