Which statement about Mycoplasma remains true?

Which statement about Mycoplasma remains true?

• A. They lack a cell wall.
• B. They have a thick cell wall.
• C. They are viruses.
• D. They are non-free-living.

Answer: (A)

Mycoplasma lack a cell wall, which is the defining trait that explains many of their distinctive properties. Without a peptidoglycan layer, their membranes are more flexible and often contain sterols, making them pleomorphic and causing Gram staining to be unreliable. This absence also means antibiotics that disrupt cell wall synthesis, like beta-lactams, are ineffective against them. They are bacteria, not viruses, and while they require special media for growth (often with cholesterol), they can be cultured independently under the right conditions. The other statements don’t fit because they do not have a thick cell wall, they are not viruses, and they are capable of free-living growth when provided appropriate nutrients.

Mycoplasma lack a cell wall, which is the defining trait that explains many of their distinctive properties. Without a peptidoglycan layer, their membranes are more flexible and often contain sterols, making them pleomorphic and causing Gram staining to be unreliable. This absence also means antibiotics that disrupt cell wall synthesis, like beta-lactams, are ineffective against them. They are bacteria, not viruses, and while they require special media for growth (often with cholesterol), they can be cultured independently under the right conditions. The other statements don’t fit because they do not have a thick cell wall, they are not viruses, and they are capable of free-living growth when provided appropriate nutrients.