Biological Species Concept. The biological species concept defines a species as members of populations that actually or potentially interbreed in nature, not according to similarity of appearance.Although appearance is helpful in identifying species, it does not define species.Appearance isnt everything.1  Organisms may appear to be alike and be different species. 2  For example, Western meadowlarks (Sturnella neglecta) and Eastern meadowlarks (Sturnella magna) look almost identical to one another, yet do not interbreed with each otherthus, they are separate species according to this definition.ppearance isnt everything. 1  Organisms may appear to be alike and be different species. 2  For example, Western meadowlarks (Sturnella neglecta) and Eastern meadowlarks (Sturnella magna) look almost identical to one another, yet do not interbreed with each otherthus, they are separate species according to this definition.
Electrical resistivity (also known as resistivity, specific electrical resistance, or volume resistivity) is an intrinsic property that quantifies how strongly a given material opposes the flow of electric current. A low resistivity indicates a material that readily allows the flow of electric current.
Conductivity (or specific conductance) of an electrolyte solution is a measure of its ability to conduct electricity. The SI unit of conductivity is siemens per meter (S/m).n alternating voltage is used in order to avoid electrolysis. The resistance is measured by a conductivity meter. Typical frequencies used are in the range 1â3 kHz. The dependence on the frequency is usually small, but may become appreciable at very high frequencies, an effect known as the DebyeâFalkenhagen effect.