The biological species concept is the most widely accepted species concept. It defines species in terms of interbreeding. For instance, Ernst Mayr defined a species as follows:species are groups of interbreeding natural populations that are reproductively isolated from other such groups..The biological species concept explains why the members of a species resemble one another, i.e. form phenetic clusters, and differ from other species.When two organisms breed within a species, their genes pass into their combined offspring.he biological species concept explains why the members of a species resemble one another, i.e. form phenetic clusters, and differ from other species. When two organisms breed within a species, their genes pass into their combined offspring.
conduit - a passage (a pipe or tunnel) through which water or electric wires can pass; the computers were connected through a system of conduits. aqueduct - a conduit that resembles a bridge but carries water over a valley. duct - an enclosed conduit for a fluid.
The Basics of Steel Conduit. Steel conduit has been in use as a raceway system for electrical conductors since the early 1900s. The wall thickness and strength of steel make metal conduit the wiring method recognized as providing the most mechanical protection to the enclosed conductors. An additional benefit of using steel conduit is that the NEC recognizes a properly installed metal conduit system as an equipment grounding conductor. Three basic types of steel conduit are in use today: rigid metal conduit, intermediate metal conduit, and electrical metallic tubing.