Nerve net Nerve net A nerve net consists of interconnected neurons lacking a brain or any form of cephalization. While organisms with bilateral body symmetry are normally associated with a central nervous system, organisms with radial symmetry are associated with nerve nets. Nerve nets can be found in members of the Cnidaria, Ctenophora, and Echinodermata phyla, all of which are found in marine environments. Nerve nets can provide animals with the ability to sense objects through the use of the sensory neurons within the nerve net. The nerve net is the simplest form of a nervous system found in multicellular organisms. Unlike
Pterobranchia mitochondrial code V) Pterobranchia mitochondrial code The pterobranchia mitochondrial code is a genetic code used by the mitochondrial genome of "Rhabdopleura compacta" (Pterobranchia). The Pterobranchia are one of the two groups in the Hemichordata which together with the Echinodermata and Chordata form the three major lineages of deuterostomes. AUA translates to isoleucine in Rhabdopleura as it does in the Echinodermata and Enteropneusta while AUA encodes methionine in the Chordata. The assignment of AGG to lysine is not found elsewhere in deuterostome mitochondria but it occurs in some taxa of Arthropoda. This code shares with many other mitochondrial codes the reassignment of the