We can observe a phenotype whether or not we understand the genetics behind it. In real life, there is a gene called HERC2 that works like I described, and most people with blue eyes have the broken allele of this gene.
Nerves, Neuroglia, and Ganglia. A nerve is a bundle of fibres (axons and/or dendrites) outside the CNS. Neuroglia are cells of the nervous system that help protect and support it. Ganglia are groups of nerve cell bodies lying outside the CNS.
Best Answer: Nervous system is a highly specialized tissue network whose principal component are cells called neurons. - peripheral nervous system (PNS): all other nervous structures that do not lie within the CNS, like nerves. Source(s): http://en.wikipedia.org/wiki/Nervous_sys...