Food Web Builder

Food Web Builder is a free KS3 biology game about food webs. A food web shows what eats what in one place, such as a meadow or a hedge. Answer questions about its links. Then take species out and see what happens to the rest.

The first six questions ask about links in the web. Tap the food button, then tap the animal that eats it. The arrow points from the food to the animal that eats it. In a normal round, the first three links start from a plant.

The last four questions use the whole food web. Tap Remove to take one species out. Then pick the animal that loses all of its food first. The answer panel lists every animal that runs out of food, in order.

Each right answer scores 10 points, and a 30-second timer runs on each question. The practice switch turns the timer off. Choose Challenge start and all six links start from animals, which is trickier. On a keyboard, press 1 to 4 to answer and Enter to go on. The best score for each start is saved on this device.

The living things in an ecosystem depend on each other. Scientists call this interdependence. An ecosystem is a place, like a pond or a wood, together with everything that lives there. Plants make their own food. Animals get theirs by eating plants or other animals.

A food chain follows one line of eating, such as clover to caterpillar to ground beetle. Real animals often eat more than one thing, and more than one animal may eat them. When you join all the food chains in a place together, you get a food web.

A food web helps you predict what happens when something changes. If one species disappears, the animals that eat it lose some of their food. An animal with other foods can switch to them. An animal that ate only the missing species runs out of food. Then the animals that ate it lose food too, and so on up the web. That chain of effects is what the removal questions test.

The web in this game is a model. It uses a small set of plants and animals from a British meadow and hedgerow. A real habitat has many more species and many more links. The model keeps things simple, so you can follow each effect by eye.

Food webs sit in the relationships in an ecosystem part of the KS3 National Curriculum for science. That part also covers insect-pollinated crops, and why insect pollination of plants matters for the food people eat. It also asks how living things affect their surroundings and are affected by them, including the build-up of poisons over time.

• Read each arrow as "is eaten by". Clover → Caterpillar means the caterpillar eats the clover.
• Plants never sit at the end of an arrow in this web. They make their own food.
• In a removal question, first find every animal that eats the missing species.
• Then check each of those animals. Does it have another food left in the web? If it does, it survives.
• In this web, the animal at the top eats more than one thing. It is never the first to lose all its food.

In a removal question, the wrong options have no direct link to the missing species. If you pick one, look back at the list and trace the arrows.