monosporic

Monosporic is an adjective used in biology to describe processes that originate from a single spore. It derives from Greek monos meaning single and sporos meaning spore.

In botany, monosporic development refers to embryo sac formation in flowering plants that arises from a single functional megaspore following meiosis. After meiosis the megaspore mother cell yields four megaspores, of which only one survives to function as the megaspore. The functional megaspore undergoes typically three mitotic divisions to produce eight haploid nuclei, which organize into the mature embryo sac (usually seven cells: one egg cell, two synergids, three antipodal cells, and a central cell with two polar nuclei). This monosporic pathway is contrasted with bisporic and tetrasporic modes of embryo sac development, where two or four megaspores contribute to the embryo sac.

In other biological contexts, monosporic can be used more broadly to indicate a life history or reproduction arising from a single spore, including certain fungal or plant-pathogenic life cycles, though such usage is less standardized and may vary by author. The term is therefore most commonly encountered in descriptions of angiosperm embryo sac ontogeny.