Energy Flow

• A food chain shows the feeding relationships between organisms
• Each organism in the food chain is called a trophic (feeding) level
• Food web shows how one or more food chains are interconnected. This is because many animals eat more than one type of food. Each animal or plant is also eaten by more than one type of animal. Hence, food web gives the overall picture of all the organisms that are involved in the transfer of energy and nutrients in an ecosystem
• • Trophic level 1: Producers (Green plants)
  • Trophic level 2: Primary consumers (Animals that eat plants, includes omnivores)
  • Trophic level 3: Secondary consumers (Animals that eat other animals)
  • Trophic level 4: Tertiary consumers (Animals that eat other animals)
• Non-cyclical nature of energy flow

  
• Energy is lost to the environment as food is transferred from one trophic level to another:

  • as thermal energy during respiration
  • in uneaten body parts
  • through undigested matter egested by consumers
  • through waste products excreted by consumers
• 90% of energy is lost when it is transferred from one trophic level to another. Only 10% is transferred to the next trophic level. As energy passes along a food chain, the amount of energy transferred gradually decreases