Answers (1) Jewels Vern. Energy is sometimes defined as capacity to do work. But work is defined as disordering energy. So energy is capacity to do disordering energy. That is a circular definition. Energy is not a physical unit. It is a philosophical concept and an accounting technique used to analyze mechanical and chemical exchanges. In nuclear physics it is defined as a wavelength of light, in biology it is a synonym for metabolism, and in public utilities they say energy when they mean connectivity. Anybody who uses the word in any other context does not know what he is talking about.
A species is often defined as the largest group of organisms where two hybrids are capable of reproducing fertile offspring, typically using sexual reproduction. While in many cases this definition is adequate, the difficulty of defining species is known as the species problem.his definition can be extended to say that a species is a group of organisms that could potentially interbreedâfish could still be classed as the same species even if they live in different lakes, as long as they could still interbreed were they ever to come into contact with each other.
1. Biology A group of closely related organisms that are very similar to each other and are usually capable of interbreeding and producing fertile offspring. The species is the fundamental category of taxonomic classification, ranking below a genus or subgenus. group of organisms having many characteristics in common and ranking below a genus. Organisms that reproduce sexually and belong to the same species interbreed and produce fertile offspring. See Table at taxonomy. a group of individuals of common parentage; a sort, kind, or variety.