Practice question

Class Mollicutes within phylum Mycoplasmatota comprises diminutive bacteria that have undergone regressive evolution deleting genes for peptidoglycan biosynthesis, resulting in complete absence of cell wall. Bounded solely by a sterol-rich trilaminar plasma membrane, they exhibit pleomorphism, inability to synthesize cell wall precursors, and intrinsic resistance to penicillins and cephalosporins. Requirement for cholesterol for membrane stability and ability to pass through bacterial filters are notable. This wall-less state necessitates osmotic protection via host association, distinguishing them from walled Firmicutes and Gracilicutes in clinical microbiology.