Which of the following adds/add carbon dioxide to the carbon cycle on the planet Earth? 1. Volcanic action 2. Respiration 3. Photosynthesis 4. The decay of organic matter Select the correct answer using the code given below.
Explanation
Statement 1 is correct: Volcanic action releases carbon dioxide trapped within the Earth's crust and mantle.
Statement 2 is correct: Respiration releases carbon dioxide as a byproduct of cellular respiration in living organisms.
Statement 3 is incorrect: Photosynthesis removes carbon dioxide from the atmosphere. Plants and other photosynthetic organisms use carbon dioxide during photosynthesis to create organic molecules.
Statement 4 is correct: The decay of organic matter releases carbon dioxide as decomposers break down dead plants and animals. This process returns carbon stored in organic matter back to the atmosphere as carbon dioxide.