The ability of a muscle to contract and relax is dependent on the flow of what substance in and out of the muscle cell?

Where is energy trapped inside the organelle chlorophyll

The skeletal system performs a variety of functions that are crucial to maintaining life processes. what function is performed in the bone marrow, but not in the ossified bones of the skeleton? a oxygen transportation c mineral storage b. muscle attachment d red blood cell production

In the water cycle , when does water undergo a chemical change