Answer:
photosynthesis is a process utilized by autotrophs to produce the products required for cellular respiration. Unlike you and me, plants and certain other Autotrophs like bacteria; can’t consume other organisms. That being said, they still require nutrients to preform cellular respiration. Those nutrients are obtained through processes such as photosynthesis.
So in other words photosynthesis produces glucose and oxygen required for aerobic/anaerobic cellular respiration, and that’s how there related.