Energy Flow in Ecosystems
What process allows green plants to make their own food using sunlight?
What is photosynthesis?
Which process in the carbon cycle removes carbon dioxide from the atmosphere?
Photosynthesis
What is ecological succession?
The gradual change in an ecosystem over time.
Organisms that make their own food are called ___________.
Producers
Name one example of a producer and one example of a consumer.
ex. Producer: grass / Consumer: rabbit
What is the main source of energy for almost all life on Earth?
What is the sun?
What role do nitrogen-fixing bacteria play in the nitrogen cycle?
They convert nitrogen gas (N₂) into usable forms plants can absorb.
Which type of succession begins in an area with no soil — such as bare rock?
Primary succession
Organisms that break down dead matter and recycle nutrients are called ___________.
Decomposers
Which cycle includes evaporation, condensation, and precipitation?
Water Cycle
Only about 10% of energy is passed to the next trophic level. What happens to the other 90%?
It is lost as heat or used for life processes.
Which nutrient cycle does not involve the atmosphere?
The phosphorus cycle
What type of succession happens after a forest fire or hurricane, when soil remains?
Secondary succession
The step or position an organism occupies in a food chain or web is called a ___________.
Trophic Level
Why do ecosystems depend on decomposers?
They recycle nutrients back into the soil and make them available for plants.
How are producers and consumers different in how they get their energy?
Producers make their own food; consumers get energy by eating other organisms.
Explain how carbon moves between plants and animals.
Plants absorb carbon during photosynthesis; animals eat plants and release CO₂ through respiration.
What are pioneer species, and why are they important?
They are the first organisms to colonize new areas and help form soil
The process of breaking down food to release energy is called ___________.
Cellular respiration
Explain one similarity and one difference between energy flow and matter cycling in ecosystems.
Both move through ecosystems, but energy flows one way and matter is reused.
Explain the difference between a food chain and a food web.
A food chain shows one path of energy flow; a food web shows many interconnected food chains.
Describe one way humans impact the carbon or nitrogen cycle.
Burning fossil fuels adds CO₂; fertilizers add excess nitrogen to soil and water.
What is a climax community?
A stable, mature ecosystem that no longer goes through major succession changes.
What term describes a network of feeding relationships showing how energy moves through an ecosystem?
Food web
Explain how energy and matter move differently through ecosystems.
Energy flows in one direction and is lost as heat; matter cycles repeatedly through living and nonliving parts.