Student Exploration: Food Chain
Vocabulary: consumer, ecosystem, energy pyramid, equilibrium, food chain, population,
predator, prey, producer
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
The Food Chain Gizmo™ shows a food chain with hawks, snakes, rabbits, and grass. In this
simulation, the hawks eat snakes, the snakes eat rabbits, and the rabbits eat grass.
1. Producers are organisms that do not need to eat other organisms to obtain energy.
A. Which organism is a producer in this food chain?
The grass is a producer in this food chain.
B. Where does the producer get its energy?
The producer gets its energy from the sun.
2. Consumers must eat other organisms for energy. Which organisms are consumers in this
food chain?
The hawks, snakes, and rabbits are the consumers in this food chain.
Gizmo Warm-up
The SIMULATION pane of the Gizmo shows the current population,
or number, of each organism in the food chain.
1. What are the current populations of each organism?
Hawks: 42 Snakes: 278 Rabbits: 2,566 Grass: 27,300
2. Select the BAR CHART tab, and click Play ( ). What do you
notice about each population as time goes by?
The population doesn’t change much.
If populations don’t change very much over time, the ecosystem is in equilibrium.
3. Notice the populations decrease as you go from the bottom of the food chain to the top. Why
, do you think this is so?
I think this is so because the lower levels need a big enough population to give energy to
the one below them.
This diagram, showing decreasing populations at each level, is called an energy pyramid.