Which of the following processes removes carbon (IV) oxide from the atmosphere?

Step 1: Analyze the question The question asks which process removes CO₂ from the atmosphere. In other words, we are looking for a process that uses up CO₂, not one that releases it.

Step 2: Explain the concept The carbon cycle has two sides:

• Processes that add CO₂ to the atmosphere: respiration (in plants and animals), burning (combustion) of fuels, decay and putrefaction by bacteria and fungi, and volcanic activity.
• Processes that remove CO₂ from the atmosphere: mainly photosynthesis, where green plants take in CO₂ through their stomata. Dissolving in oceans also removes some.

Photosynthesis equation:

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ (in the presence of light and chlorophyll)

Step 3: Check each option

• A. Burning fuels: releases CO₂ (combustion of carbon compounds). ❌
• B. Putrefaction: bacteria break down proteins in dead organisms, releasing gases including CO₂. ❌
• C. Photosynthesis: plants absorb CO₂ and use it to make glucose. ✅
• D. Respiration in plants: plants release CO₂ when they respire. ❌

Step 4: Answer The correct option is C. Photosynthesis.

Exam tip: Remember "Photosynthesis = Plants Process (take in) CO₂". Respiration, burning, and decay all give out CO₂. If a question asks about removal of CO₂, think photosynthesis first.