Question

Which of the following is the byproduct of photosynthesis?
A. Potential energy
B. Energy
C. Carbon Dioxide
D. Oxygen

Answer 1

Hint: Photosynthesis is a chemical process used by green plants and few other organisms to convert- light energy into chemical energy. The sugar produced by this process is converted into- ATP and used in other metabolic reactions.

Complete answer:
Photosynthesis is the phenomenon of conversion of light energy, absorbed by the plants in the form of sunlight to chemical energy. The chemical energy is stored in the form of sugars in the plants. It occurs in the double membranous structure of leaves- the chloroplast that is present inside the mesophyll cells of the leaves.
The sunlight absorbed by the chlorophyll cells functions as the main source of energy. Therefore, photosynthesis cannot occur in the dark.

Carbon dioxide and water are the main reactants for this process. The carbon dioxide is taken or absorbed by the stomata present in the chloroplast. Water is absorbed by the roots from the soil and transported to the leaves by the vascular tissues.
In the presence of sunlight or light energy, carbon dioxide and water react with each other to form sugar molecules- glucose. The water molecules are split into hydrogen and oxygen molecules. The hydrogen molecules react with carbon dioxide and reduce them. Photosynthesis is a redox mechanism where carbon dioxide is reduced to form glucose, and water molecules are oxidized to form oxygen molecules. The molecular oxygen formed is released as a byproduct.

Let us analyze the options to find the correct answer.

Option A: The potential energy is stored in the glucose molecules and gets converted into kinetic energy. Since the potential energy is not released as a by-product, this is an incorrect option.
Option B: Photosynthesis utilizes solar energy and releases chemical energy in the form of sugars. The glucose molecule is further converted into ATP by the process of respiration. Since no direct energy is released through this process, therefore, energy is an incorrect option.
Option C: Carbon dioxide is the primary reactant of this reaction. It is released as a by-product in cellular respiration. Therefore, carbon dioxide is an incorrect option.
Option D: Oxygen is released as a by-product in the photosynthesis to the atmosphere. This oxygen is utilized by the animals and other organisms for cellular respiration. Therefore, this is the correct option.

Hence, the correct answer is option (D)

Note: Photosynthesis is not a reversible reaction as the formation of glucose is a chemical change, which cannot be reversed. Respiration occurs in the mitochondria of cells, which follows the reverse reaction of photosynthesis. The oxygen breaks the glucose molecules to release carbon dioxide and water. This is also a redox reaction.