The correct option is (c) 1 and 3 only
Explanation
The concept of "Green Lungs" refers to the critical role played by forests and vegetation in maintaining atmospheric balance. This is achieved through the cycling of gases-specifically oxygen and carbon dioxide-between biotic components (plants and animals) via the processes of photosynthesis and respiration.
Statement-wise Analysis:
- Statement 1 is Correct: During photosynthesis, plants utilize sunlight to convert carbon dioxide ($CO_2$) and water into glucose. A by-product of this chemical reaction is oxygen ($O_2$), which is released into the atmosphere. This process replenishes the oxygen supply essential for aerobic life.
- Statement 2 is Incorrect: This statement is scientifically flawed for two reasons:
- First, for photosynthesis, plants require carbon dioxide, not oxygen.
- Second, animals do not release oxygen; they consume oxygen and release carbon dioxide during respiration. While plants do consume oxygen for their own respiration, the statement specifically links it to photosynthesis and animal release, which is factually wrong.
- Statement 3 is Correct: Animals perform cellular respiration to generate energy, a process that consumes oxygen and releases carbon dioxide ($CO_2$) as a metabolic waste product. Plants absorb this atmospheric $CO_2$ to perform photosynthesis, thereby closing the cycle of gas exchange.
Key Takeaway:
The "Green Lungs" function relies on the symbiotic exchange where plants sequester carbon dioxide (a greenhouse gas) to produce food and release life-sustaining oxygen, while animals consume oxygen and release carbon dioxide.