Energy Transfers (SQA National 5 Biology): Revision Note

Food chains & energy losses

• When biomass is consumed during feeding, energy is transferred from the food organism to the consumer; this energy transfer is represented by the arrows in food chains

• In transfers from one level to the next in a food chain, the majority of the energy is lost

• Energy losses occur because very little of the energy stored in the tissues of a food organism is used for growth by the consumer; the remaining energy is lost to the environment, e.g.:

  • in the form of heat

  • due to movement

  • within undigested food when it exits the body

• Energy lost to the environment is not stored in the biomass of the consumer and so is not available to the organism at the next level of the food chain