The following features belong to class A. Asexual reproduction by zoospores or aplanospores. B. Fusion of gametes may be isogamous, anisogamous or oogamous. C. Mycelium is aseptate and coenocytic. D. Spores are endogenously produced in sporangium.

The mycelium of Phycomycetes is aseptate and coenocytic. Asexual reproduction takes place by zoospores (motile) or by aplanospores (non-motile). Thesespores are endogenously produced in sporangium. The gametes are similar in morphology (isogamous) or dissimilar (anisogamous or oogamous).