Zoid

In botany, a zoid or zoïd /ˈzoʊ.ɪd/ is a reproductive cell that possesses one or more flagella, and is capable of independent movement.^[1] Zoid can refer to either an asexually reproductive spore or a sexually reproductive gamete. In sexually reproductive gametes, zoids can be either male or female depending on the species. For example, some brown alga (Phaeophyceae) reproduce by producing multi-flagellated male and female gametes that recombine to form the diploid sporangia.^[2] Zoids are primarily found in some protists, diatoms,^[1] green alga, brown alga,^[3] non-vascular plants,^[4] and a few vascular plants (ferns,^[1] cycads,^[5] and Ginkgo biloba^[6]). The most common classification group that produces zoids is the heterokonts or stramenopiles. These include green alga, brown alga, oomycetes, and some protists.^[7] The term is generally not used to describe motile, flagellated sperm found in animals. Zoid is also commonly confused for zooid which is a single organism that is part of a colonial animal.