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.
nerve. a macroscopic cordlike structure of the body, comprising a collection of nerve fibers that convey impulses between a part of the central nervous system and some other body region. See Appendix 2-6 and see color plates. Depending on their function, nerves are known as sensory, motor, or mixed.ensory nerve a peripheral nerve that conducts impulses from a sense organ to the spinal cord or brain. See also neuron. somatic n's the sensory and motor nerves supplying skeletal muscle and somatic tissues.