Matter cycles and energy flows throughout an ecosystem. The energy flow is continuous, but the matter flows, because it can neither be destroyed nor created. Hope this helps.
Answer:
The prefix "echin-" means D. The prefix "exo" means outside/external.
Explanation:
Among organisms, carbon compounds exist in four major categories: lipids, carbohydrates, proteins and nucleic acids. Carbohydrates are required as sources of energy. Proteins are the major molecules from which organisms are built. Lipids provide energy to produce hormones. Nucleic acids consist of deoxyribonucleic and ribonucleic acids, which play a key role in protein synthesis.
Nicolaus Copernicus in the 16th century, the Sun was believed to be the center of the universe.
Koch's postulates serve to give criteria that gives causality between a microbe and a disease.