what are two characteristics that make c. elegans a good model organism
Caenorhabditis elegans In 1963, Sydney Brenner proposed using C. elegans as a model organism for the investigation primarily of neural development in animals. It is one of the simplest organisms with a nervous system. The neurons do not fire action potentials, and do not express any voltage-gated ion channels.[51] In the hermaphrodite, this system comprises 302 neurons[52] the pattern of which has been comprehensively mapped, in what is known as a connectome, and shown to be a small-world network.[53] Research has explored the neural and molecular mechanisms that control several behaviors of C. elegans, including chemotaxis, thermotaxis, mechanotransduction, learning, memory, and mating behaviour.[54] Brenner also chose it as it is easy to grow in bulk populations, and convenient for genetic analysis.[55] It is a multicellular eukaryotic organism, yet is simple enough to be studied in great detail. The transparency of C. elegans facilitates the study of cellular differentiation and other developmental processes in the intact organism. The spicules in the male clearly distinguish males from females. Strains are cheap to breed and can be frozen. When subsequently thawed, they remain viable, allowing long-term storage.[56] Maintenance is easy when compared to other multicellular model organisms, a few hundred nematodes can be kept on a single agar plate and suitable growth medium. Brenner described the use of a mutant of E. Coli â€“ OP50. OP50 is a uracil-requiring organism and its deficiency in the plate prevents the overgrowth of bacteria which would obscure the worms.[57]
Animal Animals have several characteristics that set them apart from other living things. Animals are eukaryotic and multicellular,[5][6] which separates them from prokaryotic bacteria and eukaryotic but unicellular protists. Unlike plants and algae, which produce their own nutrients (and, with fungi, have rigid cell walls),[7] animals are heterotrophic,[6][8] consuming organic material and digesting it internally.[9] With very few exceptions, animals breathe oxygen and respire aerobically.[10] All animals are motile[11] (able to spontaneously move their bodies) during at least part of their life cycle, but some animals, such as sponges, corals, mussels, and barnacles, later become sessile. The blastula is a stage in embryonic development that is unique to most animals,[12] allowing cells to be differentiated into specialized tissues and organs.