Energy in Ecosystems
What is the main source of energy for almost all ecosystems on Earth?
The Sun
What is the original source of energy for almost all food chains on Earth?
The Sun
What does a food chain show?
How energy moves from one organism to another
What is matter?
Anything that has mass and takes up space
What does the term energy flow describe in an ecosystem?
How energy passes from one organism to another
Which part of a plant helps absorb sunlight to make food?
Leaves
How is a food web different from a food chain?
A food web includes many connected food chains.
How do decomposers help matter cycle through an ecosystem?
They break down waste and return nutrients to the soil.
In a simple food chain, which statement best describes how energy moves?
From producers to consumers to decomposers
Which statement best explains how animals get the energy they need to survive?
A. Animals create energy by sleeping.
B. Animals absorb energy from the sun through their skin.
C. Animals get energy by eating other organisms.
D. Animals produce energy using oxygen and water.
Animals get energy by eating other organisms.
Look at this simple chain: Sun → Grass → Grasshopper → Frog → Snake.
Which organism is the producer?
The grass
How is the movement of energy different from the movement of matter in ecosystems?
Energy flows in one direction, but matter is recycled.
Why does the amount of energy decrease at each level of a food chain?
Energy is lost as heat and used for life processes.
What happens to matter in a dead animal’s body?
It is eaten by decomposers and returned to the environment.
If most of the frogs in a pond die from disease, what will most likely happen to the insects they eat?
The insect population will increase.
Which of the following is a real-world example of matter cycling in an ecosystem?
Compost breaking down into nutrient-rich soil
A new species of insect eats large amounts of grass in a meadow ecosystem.
What will most likely happen to the rabbits that also eat grass?
Their population will decrease
Which of the following correctly describes how matter moves through an ecosystem?
A. Matter is recycled between living things and the environment.
B. Matter moves only from animals to the environment.
C. Matter moves in one direction from producers to consumers and then disappears.
D. Matter is created by animals and used only by plants.
A. Matter is recycled between living things and the environment.
In a forest food web, owls eat snakes, and snakes eat mice.
What might happen if all the snakes disappeared?
Mice populations would increase, and owl populations would decrease.
Explain what happens to matter and energy in this sequence:
Fallen Leaf → Earthworm → Bird → Decomposer
Matter cycles back into the soil, and energy is released as heat.