Goal and materials
Students model feeding relationships in a simple meadow and use arrows to show energy moving from a food source to the organism that consumes it. Prepare cards for grass, clover, grasshopper, rabbit, frog, snake, fox, hawk and decomposers, plus paper or a board and pencils or string. The cover image is illustrative; the card relationships below are the lesson information.
Introduce the model
A food chain is one path through a food web; a web connects several paths. In this model, grass and clover are producers. Grasshoppers and rabbits can eat plants; frogs can eat grasshoppers; snakes can eat frogs; foxes can eat rabbits. A hawk may eat snakes or rabbits in this simplified classroom model. Decomposers break down dead material and return nutrients to the environment; they do not create energy.
Build and connect paths
Place producer cards on the left. Make two paths: grass → grasshopper → frog → snake, and clover → rabbit → fox. Add the hawk and connect it to snake and rabbit cards, following this model. Join the paths into a web. An arrow points from the organism being eaten toward the organism receiving energy; it does not point toward the eater’s prey.
Student task
Complete three prompts: (1) trace a path from a producer to a predator; (2) draw an arrow between grass and grasshopper and explain it; (3) name two organisms with more than one link. Students may write, label cards or answer orally. The goal is to explain relationships, not memorize one universal list of what every animal eats.
Worked example and key
One valid path is grass → grasshopper → frog → snake. The arrow from grass to grasshopper shows energy moving from the plant to the animal that eats it. In this model, the hawk links to snake and rabbit, and producers link to more than one consumer. Accept other paths only when they follow the supplied relationships. Decomposers act on dead organisms across the web; do not show them as an energy source for plants.
Discuss a change
Remove the grasshopper card. Students may infer that frogs have one fewer food link in this model and grass is no longer eaten by this consumer. They should not claim every frog disappears or that the meadow changes in one certain way. Real ecosystems have many relationships and conditions; this card model supports reasoning about links, not prediction of a real population.
Check understanding
Use an exit ticket: “Choose one arrow and explain its direction. Name one conclusion the model supports and one it cannot prove.” If an arrow points from eater to food, ask who receives energy and redraw it. If the organisms are in a single line, ask where a second feeding link could connect. Recognize a clear explanation even if a card needs to move.
Access and extension
For younger learners, use picture cards and two organisms at a time. Offer a word bank, large print, tactile string links or oral responses. For extension, add decomposers and distinguish nutrient recycling from energy flow. Keep one arrow convention throughout. Schoolizer’s area and perimeter grid activity is a separate maths resource; do not mix its answer key into this science model.
