<prompt> Cell wall deficient organisms areChlamydiaMycoplasmaStreptococcusAnaerobes  <response>: Ans. is b i.e., Mycoplasma Mycoplasma Smallest free living organism, are prokaryotes Lack cell wall, are bounded by a triple layered unit membrane that contains sterol therefore mycoplasmas require sterol for growth. Their lack of cell wall is associated with cellular pleomorphism and resistance to cell wall - active antimicrobial agents, such as penicillins and cephalosporins 13 - lactam drugs. Multiplication is by binary fission. Unique among prokaryotes is the requirment of most mycoplasmas for cholesterol and related sterols. 