What must happen before a chemical reaction can begin?

Rue or false siblings look simila rbecause they each have some traits of their parents.

During the day, plants produce by splitting water molecules in the light-dependent reactions of photosynthesis. at the same time, plants use cellular respiration to produce some of the needed by the light-independent reactions to make sugars. during the night, plants produce because takes place.

When listening the levels of orginization in orginisims from the smallest to most complex , which level is just below organs in complexity