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.
neuron neuÂ·ron (nur'Ån', nyur'-) or neuÂ·rone (-Ån') n. Any of the impulse-conducting cells that constitute the brain, spinal column, and nerves, consisting of a nucleated cell body with one or more dendrites and a single axon. Also called nerve cell, neurocyte.