What do all prokaryotes and eukaryotes have in common? a. they are unicellular organisms. b. they are multicellular organisms. c. the cells that make them up each contain genetic information. d. the cells that make them up each contain a membrane-enclosed nucleus.

the answer would be a

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.