MTOC or microtubule-organizing center is a structure found in all plant and animal cells from which microtubules radiate. The two most important types of MTOCs are the basal bodies associated with cilia and certain intercellular junctions in epithelial cells, and the centrosome. Divisions Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta - liverworts Anthocerotophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) Lycopodiophyta - clubmosses Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta - ginkgo Gnetophyta - gnetae Magnoliophyta - flowering plants Adiantum pedatum (a fern... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria (coral, jellyfish, anenomes) Placozoa (trichoplax) Subregnum Bilateria (bilateral symmetry) Acoelomorpha (basal) Orthonectida (parasitic to flatworms, echinoderms, etc. ... This article is in need of attention from an expert on the subject. ... A basal body is a short cylindrical array of microtubules plus their associated proteins found at the base of a eukaryotic cell cilium or flagellum. ... This article is about an organelle. ... In zootomy, epithelium is a tissue composed of a layer of cells. ... The centrosome is the main microtubule organizing center (MTOC) of the cell. ...

Most animal cells during interphase have one MTOC, usually located near the nucleus, and generally associated closely with the Golgi apparatus during interphase. This MTOC is the centrosome which usually has a pair of centrioles. Microtubules are anchored with their "minus" ends in the centrosome, and because microtubules dissociate preferentially at this end, this anchoring has a stabalizing effect, and MTOC associated microtubules can grow very quickly. This directionality is also important for membrane bound transport, as the motor proteins kinesin and dynein typically move preferentially in either the "plus" or "minus" direction along a microtubule, allowing vesicles to be directed to or from the endoplasmic reticulum and Golgi apparatus. In cell biology, the nucleus (from Latin nucleus or nuculeus, kernel) is found in all eukaryotic cells and contains most of the cells genetic material. ... In cell biology, the Golgi apparatus (also called a Golgi body, Golgi complex, or dictyosome) is an organelle found in most eukaryotic cells, including those of plants, animals, and fungi. ... Interphase is a phase of the cell cycle, defined only by the absence of cell division. ... The centrosome is the main microtubule organizing center (MTOC) of the cell. ... A centriole in biology is a barrel shaped microtubule structure found in most animal cells, and cells of fungi and algae though not frequently in plants. ... This is a list of gene families or gene complexes, that is sets of genes which occur across a number of different species which often serve similar biological functions. ... Kinesins typically consist of two large globular heads that allow attachment to microtubules, a central coiled region, and a region termed light-chain, which connects the kinesin to the intracellular component to be moved. ... Dynein is one of the motor proteins (also called molecular motors) in biological cells that is able to convert the chemical energy contained in ATP into the mechanical energy of movement. ... The endoplasmic reticulum or ER (endoplasmic means within the cytoplasm, reticulum means little net) is an organelle found in all eukaryotic cells. ...

In epithelial cells, MTOCs also anchor and organize the microtubules that make up cilia. As with the centrosome, these MTOCs stabalize and give direction to the microtubules, in this case to allow unidirectional movement of the cilium itself, rather than vesicles moving along it.