Which class of fungi is uniquely characterized by having an aseptate and coenocytic mycelium?
Fungal mycelia are usually divided by cross-walls called septa. However, according to NCERT Class 11 Biology, members of the class Phycomycetes (which includes forms like Mucor and Rhizopus) are distinctly characterized by an 'aseptate' mycelium. Because they lack cross-walls, their mycelium appears as continuous, elongated tubes densely filled with a highly multinucleate cytoplasm, a specialized condition biologically termed 'coenocytic'.
Ref: NCERT Class 11 Biology > Chapter 2: Biological Classification > 2.3 Kingdom Fungi