A
Describe the water cycle.
evaporation, condensation, and precipitation
What is the source of the carbon atoms in a plant's cells?
the environment
What flows through ecosystems in one direction?
Energy
Why are food webs better representations of how energy moves through an ecosystem than food chains?
Food webs show that animals in an ecosystem can get energy by eating different things.
How are photosynthesis and cellular respiration related?
Photosynthesis and cellular respiration involve a similar set of molecules.
How does the movement of water in ecosystems differ from the movement of energy?
Water cycles through ecosystems in a continuous cycle. Energy flows in one direction.
What happens to the parts of food molecules as matter moves through an organism?
The parts of food molecules are rearranged to make new molecules or release energy.
Which describes how the atoms in living things cycle?
repeatedly back and forth through living and nonliving parts of the ecosystem
Explain how cellular respiration is the opposite reaction to photosynthesis.
Cellular respiration uses oxygen to break down sugar into carbon dioxide and water, releasing energy.