(a) Mycoplasma are the simplest unicellular prokaryotes.
(b) They are often called as PPLO (pleuropneumonia like organisms).
(c) They occur in soil, sewage, human and plants.
(d) Plasma membrane is present.
(e) Due to absence of cell wall they can change their shape easily.
(f) They lack organised nucleus, endoplasmic reticulum, plastids, mitochondria, golgi bodies, lysosomes etc.
(g) A single naked DNA duplex lies coiled in the cytoplasm.
(h) They cause several diseases such as Pneumonia in man and animals.