Please help with these 2 problems

the calvin cycle has three stages. in stage 1, the enzyme rubisco incorporates carbon dioxide into an organic molecule. in stage 2, the organic molecule is reduced. in stage 3, rubp, the molecule that starts the cycle, is regenerated so that the cycle can continue

organ system-an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

answer; synapse; i believe this is correct,plz check first good luck;