Mycoplasma (Kingdom-Monera) are the simplest and smallest free living prokaryotes which are devoid of a cell wall. Plasma membrane forms the outer boundary of the cell of mycoplasma. Nostoc is a cyanobacterium (Kingdom- Monera), in which cell wall comprises of peptidoglycans. Aspergillus is a fungus (Kingdom-Fungi) in which cell wall is mainly made of chitin. Funaria is a bryophyte (Kingdom-Plantae) in which cell wall is cellulosic in nature.