During photosynthesis in green plants, how do the levels of oxygen (\(O_2\)) and carbon dioxide (\(CO_2\)) change over time in a closed environment exposed to light?

• A. \(O_2\) increases, \(CO_2\) decreases
• B. Both \(O_2\) and \(CO_2\) increase
• C. \(O_2\) decreases, \(CO_2\) increases
• D. Both \(O_2\) and \(CO_2\) decrease

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the process of photosynthesis. Photosynthesis is the process by which green plants use light energy to convert carbon dioxide (\(CO_2\)) and water (\(H_2O\)) into glucose (\(C_6H_{12}O_6\)) and oxygen (\(O_2\)). The general equation for photosynthesis is: $6_{\mathrm{CO}}+6_H{2}_O\to C_{6_H}+6_O$. This reaction occurs in the presence of light and chlorophyll.
2. Step 2: Analyze the role of \(CO_2\) in photosynthesis. Carbon dioxide (\(CO_2\)) is a reactant in the photosynthesis process. Plants absorb \(CO_2\) from their surroundings to produce glucose. In a closed environment exposed to light, the \(CO_2\) levels will decrease over time as it is consumed during photosynthesis.
3. Step 3: Examine the role of \(O_2\) in photosynthesis. Oxygen (\(O_2\)) is a byproduct of photosynthesis. As plants convert \(CO_2\) and \(H_2O\) into glucose, \(O_2\) is released into the environment. In a closed environment exposed to light, the \(O_2\) levels will increase over time as it is produced during photosynthesis.
4. Step 4: Consider the conditions of a closed environment exposed to light. In this scenario, photosynthesis will proceed as long as light is available, leading to a continuous decrease in \(CO_2\) levels and an increase in \(O_2\) levels.
5. Step 5: Match the observations to the correct answer. Based on the analysis, the correct answer is: '\(O_2\) increases, \(CO_2\) decreases'. This aligns with the expected changes in gas levels during photosynthesis in a closed environment exposed to light.