What distinguishes Mycoplasmas from other bacteria?

Mycoplasmas are uniquely identified by the complete absence of a cell wall, which sets them apart from most other bacteria that typically possess a rigid cell wall made of peptidoglycan. This lack of a cell wall is significant because it affects their shape, making them more pleomorphic, meaning they can assume various shapes rather than being restricted to a specific form. The absence of a cell wall also makes Mycoplasmas inherently resistant to antibiotics that target cell wall synthesis, such as penicillin, which is ineffective against them.

In addition, this unique characteristic allows Mycoplasmas to be adaptable to various environments, including the cellular environment of host organisms, where they can cause infections. Their small size contributes to their capability to pass through filters that would normally retain bacteria with cell walls, allowing them to be categorized differently.

Furthermore, the other options do not accurately describe Mycoplasmas. While they do reproduce in host cells, they are not exclusively reliant on them for reproduction, as they can also grow in cell-free media under the right conditions. Regarding size, Mycoplasmas are typically smaller than many other bacteria, making them difficult to visualize with standard light microscopy; they often require more advanced techniques, like fluorescence microscopy, for detailed