herbivore A consumer of producers in a community; often organisms that eat plants.
omnivore A consumer in a community that eat both producers and consumers; usually
eaters of both plants and animals.
producer An organism that can absorb the energy of the sun and convert it into food
through the process of photosynthesis; i.e. plants and algae.
trophic level A level of the food chain reflected in the ecological pyramid.
Points to Consider
- Animals are carbon-based organisms. When animals decompose, what happens to the
carbon? Discuss this with your class. - We need nitrogen to make our DNA. Where does it come from? Where does it go?
What would happen to nitrogen released from decaying organisms? - Water is essential for photosynthesis. Water moves through both the living and non-
living parts of an ecosystem. How does water move through the living parts of an
ecosystem?
24.2 Lesson 24.2: Cycles of Matter
Lesson Objectives
- Describe the key features of the water cycle.
- Describe the key features of the nitrogen cycle.
- Describe the key features of the carbon cycle.
Check Your Understanding
- What types of organisms break down animal remains and wastes to release nutrients?
- What are the main chemical elements that are essential for life?
Introduction
What happens to all the plants and animals that die? Do they pile up and litter ecosystems
with dead remains? Or do they decompose? The role of decomposers in the environment
oftengoesunnoticed, buttheseorganismsareabsolutelycrucialforeveryecosystem. Imagine