What information does a star’s spectrum offer about the star?

The spectrum of light from a star will have dark bands in it.  These dark bands can be used to determine what atoms are in the star's atmosphere, and hence what it is made of.

The answer is water molecules are split.cellular respiration and photosynthesis are complement  reactions to each other. these are reverse reactions. in cellular respiration glucose and oxygen yield water and carbon dioxide. so, when respiration begins,  glucose molecules are split. in the opposite reaction - in photosynthesis, carbon dioxide and water yield glucose and oxygen. thus,  when respiration begins, water molecules are split.