Question

Which of the following is not essential for photosynthesis?
A. Oxygen
B. Carbon dioxide
C. Sunlight
D. Sunlight

Answer 1

Hint: Photosynthesis is a process of making food by green plants in the presence of sunlight. It is the process by which light energy gets converted into chemical energy. Plants require certain raw materials to carry out photosynthesis to produce food in the form of carbohydrates (i.e., glucose).

Complete step by step answer:
Option (A) is correct. Oxygen is not essential for the process of photosynthesis because oxygen is released in this process when plants utilize the raw materials i.e., carbon dioxide and water to produce sugars (glucose). Hence, it is not essential to carry out the process of photosynthesis.
Option (B) is incorrect. Carbon dioxide is an essential component of photosynthesis in plants to make food. It is the carbon dioxide molecule that reacts with water to form glucose and oxygen.
Option (C) is incorrect. Sunlight is one of the important requirements to carry out photosynthesis by plants. As photosynthesis is carried out in two phases i.e., light and dark phase so, in the light phase, energy from the sunlight is used to split the water molecule which releases two electrons that are used to form NADPH and ATP molecules.
Option (D) is incorrect. The whole process of photosynthesis takes place in the chloroplasts of a plant that contains a green-colored pigment called chlorophyll. It is the chlorophyll molecule that is meant for absorbing the light rays coming from the sun. Hence, it is essential for photosynthesis.

Hence, the correct option is (A)

Note:
Plants containing chlorophyll use carbon dioxide, water, and sunlight to produce food (in the form of glucose) and release oxygen with the formation of ATP and NADPH. As oxygen is produced by plants, so, it is not an essential component to start the process of photosynthesis.