Question isn't complete but explanation will be given for each option
Answer and Explanation:
A. Respiration: respiration occurs when organisms take in oxygen, combine it with glucose to release carbon dioxide, water and ATP. Respiration is different from breathing since it is more of a biochemical process than physical process.
B. Feedback inhibition: feedback inhibition occurs in metabolism when an the end product of an enzyme inhibits further production of end products by the enzyme in order to reduce concentration and reduce waste that occurs when more is produced than needed by cells.
C. Circulation: circulation involves the heart, arteries and veins whereby the heart pumps blood( which carries oxygen,hormones and nutrients) and the arteries move them in circulation through the body and back to the heart through the veins, giving off waste products.
D. Cellular activity: cells are the most basic form of life known. Cellular activities are basically the activities of cells in an organism. Examples of cellular activities include: work of enzymes in digestion, cell division, synthesis of protein from amino acids etc.
