Yeasts are fungi that grow as single cells, producing daughter cells either by budding (the budding yeasts) or by binary fission (the fission yeasts). They differ from most fungi, which grow as thread-like hyphae.

1) Binary fission – During binary fission, one cell divides itself in half across the long axis, giving rise to two new daughter cells. Since most fungi form hyphae, fission does not necessarily involve physical separation of the cells present, but does involve mitosis (separation of the chromosomes).

In binary fission a mature cell elongates and its nucleus divides into two daughter nuclei. The daughter nuclei separates, cleaves cytoplasm centripetally in the middle till it divides parent protoplasm into two daughter protoplasm.

In general, fungi grow as either yeast or filamentous fungi. Yeast divide by either budding or fission, whereas molds grow by apical extension of their filaments, known as hyphae (singular = hypha). This hyphal growth can occur with or without cell-wall separation of cellular compartments, which is known as septation.

Binary fission is a process that plays a role in the reproduction and proliferation of various microorganisms and organelles. This method allows for rapid population growth, making it important for understanding microbial ecology and evolution.