A cilium (c) is a motile organelle that arises from a basal
body (bb) (kinetosome) located in the cell’s cortex. Most basal
bodies or their homologs, centrioles, from protists to man are
composed of 9 triplet fibers made of tubulin. The cilium is composed
of 9 doublet fibers that are extensions of the triplets. There are two
singlet fibers in the center of the cilium which are not present in
the basal body. At least one of these singlets arises from an electron
opaque body, the axosome (ax), at the proximal end of the
cilium’s core. A band of postciliary microtubules (pc mt)
passes posteriorly from the proximal end of the basal body and arcs
toward the epiplasm (ep) that lies under the alveolus
(al). EM taken on 1/28/65 by R. Allen with RCA EMU3F TEM. Neg.
16,000X. Bar = 0.5µm. Published in J. Protozool. 14:553-565, 1967.
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