What is this skill?
An ecosystem is a community of living things and the nonliving parts around them, such as soil, water and sunlight, all connected. The connections are easiest to see in food chains. Producers, like grass and trees, make their own food using sunlight. Consumers eat other living things: herbivores eat plants, carnivores eat other animals and omnivores eat both. Decomposers, such as mushrooms, fungi and earthworms, break down dead plants and animals and return nutrients to the soil.
In this practice a child answers "Which one is a producer?" (grass, not a rabbit or a fox) and "Plants make their own food using ___" (sunlight). A sort puts an oak tree and wheat with producers, a deer and a wolf with consumers and a mushroom and an earthworm with decomposers, and another sorts cows and goats as herbivores, lions and eagles as carnivores, and bears and raccoons as omnivores. Ordering questions put a food chain in order, starting with the energy source (sun, grass, grasshopper, frog, snake) or the producer in an ocean chain (algae, krill, fish, seal, shark). Other questions ask where the energy in a food chain starts (the sun), what a food web is (many connected food chains), and what the arrows in a food chain diagram show (energy moving to the eater). The hardest questions ask what would happen if all the grass in a meadow died (herbivores would run out of food) and what happens first when more foxes move in where foxes eat rabbits and rabbits eat clover (fewer rabbits, so clover may grow more).
Why it matters
Ecosystems teach one of the most useful ideas in science: parts of a system affect each other. Change one link, such as the number of foxes, and the effects ripple out. That kind of thinking applies to weather, health, economies and anything with moving parts.
It also connects to the news children hear about habitats, pollution and endangered animals. A child who understands food chains can see why losing one species can matter to many others.
The skill builds on earlier science. Plants and the sun, animal needs, habitats and the cycles of matter all come together here, and fifth grade is a good time to tie them up.
Common mistakes
- Drawing food chain arrows the wrong way. The arrow points from the food to the eater, because it shows the energy moving. Grass to rabbit, not rabbit to grass.
- Forgetting the sun. Almost every food chain on Earth starts with light, which producers turn into food.
- Leaving out decomposers. They are easy to miss because they are small, but they return nutrients to the soil so that plants can grow again.
- Assuming that if a predator goes away, everything improves for the prey. More rabbits might mean less clover, so the effect continues down the chain.
How to help at home
- Draw a food chain from a meal. A hamburger, a salad or a bowl of cereal each lead back to a plant and the sun. Draw arrows toward the eater.
- Look under a log or in a compost pile and find decomposers at work. Ask your child what would happen if there were none.
- Make a backyard food web with a handful of cards: a plant, a bug, a bird, a cat. Connect them with string and remove one to see what changes.
- Watch a nature video together and pause to ask who is a producer, a consumer or a decomposer.
Worked examples
These are real questions from the Tutorsaurus ecosystems and food chains practice, with the answers worked out.
Example 1
An animal that eats only plants is a ___.
Choices: Herbivore, Decomposer, Carnivore
Answer: Herbivore. Herbivores eat only plants. Cows, rabbits and deer are herbivores.
Example 2
A food web shows many connected food chains.
Answer: True. True! Most animals eat more than one thing, so food chains link together into a food web.
Example 3
Foxes eat rabbits, and rabbits eat clover. More foxes move in. What happens first?
Choices: More rabbits, Fewer rabbits, so clover may grow more, Clover disappears right away
Answer: Fewer rabbits, so clover may grow more. More foxes eat more rabbits. With fewer rabbits eating clover, the clover can grow more. Everything is connected.
Printable worksheet (PDF) — one page of questions from this practice that work on paper, easier ones first, with an answer key on page 2. Free to print, no sign-up.