Lesson 7 of 8

Lesson 7: Ecology and Earth's Cycles

Ecology is the study of how living things interact with each other and their environment. An ecosystem is all the living and nonliving things in an area working together.

Energy Flow

  • Producers (plants) make their own food from sunlight
  • Consumers eat other organisms (herbivores, carnivores, omnivores)
  • Decomposers (bacteria and fungi) break down dead matter and recycle nutrients
  • A food chain shows one path of energy; a food web shows many connected chains

KEY TERM

In an energy pyramid, only about 10 percent of the energy passes to the next level. That is why there are many plants, fewer plant-eaters, and even fewer top predators.

The Carbon and Water Cycles

  • Carbon cycle: carbon moves through photosynthesis, respiration, decay, and the burning of fuels
  • Water cycle: water moves by evaporation, condensation, precipitation, and collection

ON THE TEST

Energy flows one way through an ecosystem and is lost as heat. Matter like carbon and water is recycled again and again.