Scientists say that photosynthesis and cellular respiration are reciprocal processes. why? a) they use different cellular organelles. b) the products of one process are the reactants of the other. c) water is broken down in one process and formed in the other. d) autotrophs are responsible for photosynthesis while heterotrophs are responsible for cellular respiration.

The correct answer is option B, that is, the products of one process are the reactants of the other.  

Cellular respiration and photosynthesis are associated with each other via an essential relationship, that is, the products of one process are the reactants of the other. Photosynthesis generates glucose, which is utilized in cellular respiration to produce ATP. The glucose is then converted back to CO2 and is used in the process of photosynthesis.  

In photosynthesis, water is dissociated to produce oxygen, while in cellular respiration oxygen combines with hydrogen to produce water. The process of photosynthesis needs CO2 and discharged O2, while in cellular respiration, oxygen is required and CO2 is discharged.