Cycle Basics
What does the word “cycle” mean?
A process that repeats continuously.
What process changes liquid water into water vapor?
Evaporation.
What carbon-containing gas is absorbed by plants?
Carbon dioxide.
What provides most of the energy that drives the water cycle?
The Sun.
What human activity releases large amounts of carbon dioxide from coal, oil, and gasoline?
Burning fossil fuels.
What is a biogeochemical cycle?
The continuous movement and recycling of matter between living organisms and the environment.
What process changes water vapor into tiny liquid droplets that form clouds?
Condensation.
What process allows plants to use carbon dioxide, water, and sunlight to make food?
Photosynthesis.
Where is most of Earth’s water stored?
In the oceans.
How does cutting down forests affect the carbon cycle?
Fewer trees are available to absorb carbon dioxide.
What two major components exchange matter during biogeochemical cycles?
Living components and nonliving components.
Water falls from the clouds as rain. What process is occurring?
Precipitation.
What process releases carbon dioxide when organisms break down food for energy?
Cellular respiration.
How does carbon move from plants to animals?
Animals obtain carbon by eating plants or other animals.
Roads and buildings cover the soil with concrete. How can this affect the water cycle?
It reduces infiltration and increases surface runoff.
Why must water and carbon be recycled in an ecosystem?
Because organisms need them for survival, growth, and important life processes.
After heavy rain, water enters the spaces between soil particles. What process is this?
Infiltration.
A dead animal is broken down by bacteria and fungi. What carbon-cycle process is occurring?
Decomposition.
Rainwater flows over the ground and enters a river. What process is happening?
Surface runoff.
A community throws garbage into drainage canals. What may happen during heavy rainfall?
The blocked drainage may cause flooding and water pollution.
Matter is recycled in ecosystems, but energy is not. What happens to energy?
Energy flows in one direction and is eventually released as heat.
Plants absorb water through their roots and release water vapor through their leaves. What process releases the vapor?
Transpiration.
When gasoline, coal, or wood is burned, stored carbon is released into the atmosphere. What process is this?
Combustion.
Explain how photosynthesis and respiration connect plants and animals in the carbon cycle.
Plants absorb carbon dioxide during photosynthesis, while plants and animals release carbon dioxide during respiration.
Give two actions students can do to reduce harmful effects on the water and carbon cycles.
Possible answers include conserving water, planting trees, reducing waste, recycling, walking, biking, and saving electricity.