Which gas is essential for the process of photosynthesis in plants?

Photosynthesis is a critical process by which plants convert light energy into chemical energy, ultimately producing food in the form of glucose. During this process, carbon dioxide plays a vital role as one of the raw materials. Plants absorb carbon dioxide from the atmosphere through small openings in their leaves known as stomata.

In the presence of sunlight and water, the absorbed carbon dioxide undergoes a series of chemical reactions in the chloroplasts of plant cells, leading to the production of glucose and oxygen. While oxygen is indeed a byproduct of photosynthesis and essential for many forms of life, it is not required as a raw material for the photosynthesis process itself. On the other hand, nitrogen and argon do not play a direct role in photosynthesis. Nitrogen is primarily used for building proteins, and argon is an inert gas that does not participate in biological reactions. Thus, carbon dioxide is the essential gas needed for photosynthesis, making it the correct answer.