15 points. how are photosynthesis and respiration related to each other? a: both are performed by all plants and animals. b: the products of photosynthesis, oxygen and glucose, are the starting substances of cellular respiration. two of the products of respiration, carbon dioxide and water, are the starting substances of photosynthesis. plants and animals depend on each other and these two important processes to survive. c: photosynthesis and respiration are not related to each other.

Photosynthesis makes the glucose that is used in cellular respiration to make ATP. The glucose is then turned back into carbon dioxide, which is used in photosynthesis. While water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water. While photosynthesis requires carbon dioxide and releases oxygen, cellular respiration requires oxygen and releases carbon dioxide. It is the released oxygen that is used by us and most other organisms for cellular respiration. Therefore the answer is B

During photosynthesis, the plant needs carbon dioxide and water both which are released into the air during respiration. And during respiration, the plant needs oxygen and glucose, which are both produced through photosynthesis!