The rate of decomposition of organisms is faster in the tropical rain forest than in other biomes because

Step 1: Analyze the question We are asked why dead organisms break down faster in the tropical rain forest than in other biomes. So we need the factor that most directly speeds up decomposition.

Step 2: The concept Decomposition is carried out mainly by bacteria and fungi (decomposers). These microorganisms thrive when there is:

• Warmth (enzymes work best at warm temperatures)
• Moisture (microbes need water to be active and grow)
• Oxygen and available organic matter

The tropical rain forest has high temperatures all year and heavy rainfall and high humidity. Together, these create ideal conditions for decomposers.

Step 3: Evaluate each option

• A. Relatively constant daylight: Light does not directly affect decomposers like bacteria and fungi. Not the reason.
• B. More plants per square foot: This means more dead material, but it does not make the rate of decay faster. Not the reason.
• C. Abundance of water: Moisture keeps decomposers active and speeds up their enzyme action. This fits.
• D. Constant cool temperature: The rain forest is warm, not cool, and cool temperatures would slow decomposition. Incorrect.

Step 4: Answer The best option is C, because the abundance of water (rainfall and humidity), together with the warm temperature, favours rapid growth and activity of decomposers.

Exam tip: Remember "warm + wet = fast decay." Cold or dry biomes (tundra, desert) have slow decomposition. If you see "cool" in an option about the tropics, eliminate it immediately.