During photosynthesis plants need constant supply of sunlight but they produce glucose a constant supply for respiration.
Step-by-step explanation:
Photosynthesis take place in 2 steps, First is light dependent and followed by the light independent phase.
The light independent reaction two important molecules are formed, they are ATP and NADH. This reaction phase takes place in the thylakoid membrane of the chloroplast in the presence of sunlight. Because of this continuous supply of sunlight is required for photosynthesis. This will be followed by Calvin-cycle or light independent reaction where glucose and Carbon dioxide are the end products.
In cellular respiration glucose is the substrate along with oxygen forms energy for various metabolic activities to take place inside the organism.
So, it is seen that product of photosynthesis is the reactant for cellular respiration.