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
Branching order of bacterial phyla (Woese, 1987) Branching order of bacterial phyla (Woese, 1987) There are several models of the Branching order of bacterial phyla, one of these was proposed in 1987 paper by Carl Woese. The branching order proposed by Carl Woese was based on molecular phylogeny, which was considered revolutionary as all preceding models were based on discussions of morphology. ("v." Monera). Several models have been proposed since and no consensus is reached at present as to the branching order of the major bacterial lineages. The gene used was the 16S ribosomal DNA. The names have been changed to reflect more current nomenclature used by