In most food chains, all of the energy originally comes from:

• A. decomposers
• B. the Sun
• C. the soil
• D. chemical bonds in glucose

Answer: (B)

Verified step by step guidance

1. Step 1: Begin by understanding the concept of energy flow in food chains. Energy in ecosystems originates from a primary source, which is used by producers to create energy-rich compounds.
2. Step 2: Recall that producers, such as plants, algae, and some bacteria, use photosynthesis to convert light energy into chemical energy stored in glucose. This process relies on sunlight as the primary energy source.
3. Step 3: Decomposers play a role in breaking down organic matter and recycling nutrients, but they do not serve as the original source of energy in food chains.
4. Step 4: The soil provides essential nutrients for plant growth but is not the source of energy for the food chain. It supports producers but does not generate energy itself.
5. Step 5: Chemical bonds in glucose store energy, but this energy is derived from the Sun during photosynthesis. Therefore, the Sun is the ultimate source of energy in most food chains.