<Tr> <Td> centriole </Td> <Td> anchor for cytoskeleton, organizes cell division by forming spindle fibers </Td> <Td> Microtubule protein </Td> <Td> animals </Td> </Tr> <Tr> <Td> cilium </Td> <Td> movement in or of external medium; "critical developmental signaling pathway". </Td> <Td> Microtubule protein </Td> <Td> animals, protists, few plants </Td> </Tr> <Tr> <Td> cnidocyst </Td> <Td> stinging </Td> <Td> coiled hollow tubule </Td> <Td> cnidarians </Td> </Tr> <Tr> <Td> eyespot apparatus </Td> <Td> detects light, allowing phototaxis to take place </Td> <Td> </Td> <Td> green algae and other unicellular photosynthetic organisms such as euglenids </Td> </Tr>

A double membrane bound organelle which contains the information storage molecule