ABSTRACT
The filamentous Ascomycetes a are fungi that produce sexual spores by free cell formation following karyogamy and meiosis in a specialized sac-like structure called an ascus. The spore is an ascospore. The ascospore contains one or more haploid nuclei and upon germination produces multinucleated septate assimilative filaments called hyphae or mycelia (singular, hypha and mycelium). The septum or cross wall, which is perforated, provides structural strength, but does not prevent movement of cytoplasm, nutrients, nuclei, or mitochondria. The cross walls divide the hypha up into cell-like compartments. The term "cell" may not be appropriate for these compartments, because the cytoplasm can be continuous from one to another.
