Question

If a plant is releasing carbon dioxide and taking in oxygen during the day, does it mean that there is no photosynthesis occurring? Justify your answer.

Answer 1

Hint: The process of taking in oxygen and giving out carbon dioxide is known as respiration. Whereas in photosynthesis, the plants take in carbon dioxide from the atmosphere and utilise it for preparing carbohydrates and release oxygen as a by-product. Photosynthesis occurs during the day in the presence of sunlight.

Complete answer:
To solve this question, we must know about the physiological process in plants. The major physiological processes in plants are respiration, photosynthesis, excretion etc. The plants take in carbon dioxide and give out oxygen through the process of photosynthesis. This process is dependent on light and takes place in the daytime. They prepare their food in the form of carbohydrates. This carbohydrate is broken down through oxidation. The oxygen is taken in through the process of respiration. This breakdown of food liberates carbon dioxide which is released into the air. This process liberates energy in the form of ATP which is essential for the growth and development of living organisms. Respiration is independent of the sunlight and occurs throughout day and night.

These two processes are independent of each other and can occur simultaneously during the daytime. At night, due to the absence of sunlight, respiration takes place which releases carbon dioxide.

Note: With the help of photosynthesis, the plants convert solar energy into chemical energy. By the process of cellular respiration, the plants convert this chemical energy into energy that can be utilised by the plants. Both the processes are important for the physiology of the plants. Excretion is also an important physiological process that involves the elimination of waste.