Based on morphology of mycelium mode of spore formation, fruiting bodies  there are  4 classes;

a).       Phycomycetes

b).       Ascomycetes

c).       Basidiomycetes

d).       Deuteromycetes

1.       Phycomycetes :

·   are found in aquatic regions or  decaying wood

.   mycelium is aseptate and  coenocytic

·    asexual reproduction takes place by zoospores (motile ) or  aplanospores ( non motile )

·     e.g. Rhizopus, mucor.

2.       Ascomycetes : (Sac fungi)

·       are mostly  Multicellular  (penicillium ) and rarely Unicellular ( yeast )

·       are saprophytic , decomposers , parasitic or  coprophilous.

·       Mycelium is branched and septate

.      Their asexual spores are called conidia and Sexual spores are called ascospores.

e.g.  Aspergillus, Neurospora

3.      Basidiomycetes :

·      They grow in soil, logs of wood , tree stumps, in plant bodies as parasitic (as rust and smuts).

·      Mycelium is branched and septate

·      Reproduction by fragmentation

·    Dikaryon ,basidium ,karyogamy(e.g. Mushroom/ bracket fungi/ puffballs)

4.    Deuteromycetes :also known as Imperfect fungi. because only the asexual or vegetative phases of these fungi are known.

.         Mycelium is septate and branched.

·         Only asexual reproduction by conidial spores

·         Saprophytes / parasitic / decomposers

·         Help in Mineral cycling

·         e.g. Trichoderma, Alternaria