fungi are non-green plant organism, they are saprophytic or parasitic. The saprophytic fungi are beneficial to man, why that of parasitic causes different type of disease to man. Fungi been saprophytic or parasitic, they cannot manufacture their food by using sun light directly, in such case they depend on already made food for their survival, as such they are called non-photosynthetic organisms. Fungi are dichotomy organism which grows either single cell as in yeast or colonies as multicultural hyphae, i.e., mould.
Fungi mode of reproduction is by replication of spores, in recognition of the spore is what is used as their mode of identification. As it was stated previously, some fungus cause disease to living organism for detail sees mycology.
They are small microscopic organism, in some ways, they are place in between bacteria and viruses. The intermediate of the microorganism between bacteria and viruses is that reckkettesiae have characteristic of both bacteria and viruses. The similarity of these organism with bacteria is that the inner core of the organism contain DNA and RNA which bacteria contain, also have the same metabolic enzyme, and reproduce by binary fission as the bacteria does, while the similarity of it with viruses is that they can only replicate within the living cells of their host as virus does.Chlamydia: these also have a similar relationship with bacteria of been having the same concentration of DNA and RNA in the inner core of their bodies, as the bacteria poses and poses muramic acid as a chemical composition of their outer shells walls, as the bacteria poses Chlamydia are intracellular organism, their size is double of that of rickettsiae. The organism is very reactive to any interferon administer to it. Prions are the causative agents of a distinct group of unseals neurological disease (the transmissible degenerative encephalopathy’s TDE) which share the common features of prolonged incubation times. The known TDE include Creutzfeldt Jacob disease (CJD) it affect human being worldwide Scrapies which also affect sheep in some area of the world, Mink Encephalopathy which occur sporadically in North American and Europe, Kuru which affect human but is confined to paupua New Guinea and bovine spongiform encephalopathy (BSE) which affect cattle. Perions are elemental particles which are resistance to the action of chemical disinfectant and formaldehyde and withstand autoclaving at 121 degree Celsius for 15 minutes. A number of theories exist as to the nature of this infectious agents but it has never been isolated on artificial media or in tissue culture (Baker & Silverton, 1998: 252).