Most cell types contain primary cilia. These are non-motile, and are used in various forms of signal transduction. http://jcs.biologists.org/content/123/4/499. read more
Eukaryotic cells have DNA enclosed in a double membrane called the nucleus. The nucleus functions to separate the DNA from other activities that occur in the cytoplasm. read more
A cilium (from Latin, meaning 'eyelash'; the plural is cilia) is an organelle found in eukaryotic cells. Cilia are slender protuberances that project from the much larger cell body. There are two types of cilia: motile cilia and nonmotile, or primary, cilia, which typically serve as sensory organelles. read more