Model Organism: Nematodes
Nematodes (Caenorhabditis elegans) were first used to study the nervous system. Subsequently, they have been used to study an array of different genetically determined processes, from embryonic development to the control of aging. They live in soil wherever it is found. C. elegans are about 1 millimeter long, transparent, and composed of 959 cells. Because of their tiny size, limited number of cells, hermaphroditic reproductive strategy, and interesting (but not too complex) behaviors, these worms are studied in laboratories around the world.