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Which one of the following statements about mycoplasma is wrong?
A
They are pleomorphic
B
They are sensitive to penicillin
C
They cause diseases in plants
D
They are also called PPLO
Detailed Solution
Mycoplasmas are the smallest living cells known, and they completely lack a cell wall.
Penicillin acts by inhibiting the synthesis of the peptidoglycan cell wall of bacteria. Since mycoplasmas have no cell wall, penicillin has no effect on them; they are resistant, not sensitive, to penicillin.
So the statement that they are sensitive to penicillin is wrong. (They are sensitive to antibiotics that act on protein synthesis, such as tetracycline.)
Because they lack a rigid wall they have no fixed shape and are pleomorphic.
They are pathogenic in animals and plants, for example causing little leaf of brinjal and witches' broom.
They are also called PPLO (pleuropneumonia-like organisms).
The other three statements are therefore correct.
Penicillin acts by inhibiting the synthesis of the peptidoglycan cell wall of bacteria. Since mycoplasmas have no cell wall, penicillin has no effect on them; they are resistant, not sensitive, to penicillin.
So the statement that they are sensitive to penicillin is wrong. (They are sensitive to antibiotics that act on protein synthesis, such as tetracycline.)
Because they lack a rigid wall they have no fixed shape and are pleomorphic.
They are pathogenic in animals and plants, for example causing little leaf of brinjal and witches' broom.
They are also called PPLO (pleuropneumonia-like organisms).
The other three statements are therefore correct.