Cnidocytes
Animals from the phylum Cnidaria have stinging cells called cnidocytes. Cnidocytes contain large organelles called (a) nematocysts that store a coiled thread and barb. When hairlike projections on the cell surface are touched, (b) the thread, barb, and a toxin are fired from the organelle.
Source
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"OpenStax College, Biology. November 17, 2013."
http://cnx.org/content/m44664/latest/?collection=col11448/latest
OpenStax CNX
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