ENCYCLOPÆDIA BRITANNICA reproduction process by which organisms replicate themselves. In a general sense reproduction is one of the most important concepts in biology: it means making a copy, a likeness, and thereby providing for the continued existence of species. Although reproduction is often considered solely in terms of the production of offspring in animals and plants, the more general meaning has far greater significance to living organisms. To appreciate this fact, the origin of …showed first 75 words of 4055 total…

…showed last 75 words of 4055 total…organism to make any substance that existed in a previous generation. Proteins are reproduced directly; however, such other substances as carbohydrates, fats, and other organic molecules found in cells are produced by a series of enzyme-controlled chemical reactions, each enzyme being derived originally from DNA through messenger RNA. It is because all of the organic constituents made by organisms are derived ultimately from DNA that molecules in organisms are reproduced exactly by each successive gen