The origin of replication (also called the replication origin) is a particular sequence in a genome at which replication is initiated.
It is the interaction of two or more substances, resulting in chemical changes in them. Chemical reactions take place when some kind of energy is supplied to them. The supplied energy may be in the form of heat, light or mechanical shaking for proper contact between the reactant molecules or electricity.
how to make chemical reactions. Chemical reactions occur when two substances are put together, and they react to form new products. The substances put together are called reactants and the resulting substances are called products.