biological species concept. Members of the same species are capable of interbreeding, producing viable offspring, and cannot produce viable offspring with members of other species. This is one of several concepts that define a species, and is the most commonly used and accepted of those concepts.he most common method for species differentiation is the biological species concept, which defines a species as a population of organisms that can interbreed to produce viable, fertile offspring.
Electric current definition. Electrical current is the flow rate of electric charge in electric field, usually in electrical circuit. Using water pipe analogy, we can visualize the electrical current as water current that flows in a pipe. The electrical current is measured in ampere (amp) unit.
Although we know that, in metal conductor at least, an electric current is a flow of negative charges (electrons) that flow from negative to positive, many (but by no means all) textbooks still use Franklin's current direction which is called 'Franklinian Flow' or, more commonly, 'Conventional Flow'.he conventional definition of current preceded the discovery of  the electron and its negative charge, so that it was defined as the  flow of positive charges (from an area â¦ of more to an area with  less).