Teeth, digestion and food chains

Model the journey of your food

What happens to a cracker on its way through the digestive system?

25 minAt home

Watch first

Follow energy as it passes from plants to animals along a food chain.

What you need

Tick each one as you find it — 0 of 6 ready.

Stay safe: Do not eat anything once it has been in the bag or the tights. Wash your hands afterwards.

Plan the fair test

Objectives this evidences

Describe the simple functions of the basic parts of the digestive system in humans

Do it, one step at a time

Step 1 of 5

Step 1. Break one cracker into the bag with a fork — that is your teeth chewing.
Step 2. Add a splash of water or juice and squeeze the bag for a minute. This is the stomach, mixing food with juices.
Step 3. Pour the mush into the leg of the tights and squeeze it slowly along — this is the small intestine, where the goodness is squeezed out.
Step 4. Catch anything that comes through the fabric in the jug: that is what gets absorbed into the blood.
Step 5. What is left inside the tights is what leaves the body. Compare it with the whole cracker on the plate.

What should happen

The well-chewed, well-mixed cracker gives up much more liquid. Chewing and stomach juices break food into pieces small enough to be absorbed.

Think about: Try it again with a cracker that is hardly chewed. Why does chewing properly matter so much?

Write up your result

What did you measure, and what pattern did you see?

A sentence or two is enough to save it.

The lessons behind this practical

Each one opens with the same short film, and the film has a written transcript underneath if reading is easier than watching.

Now the quiz for this topic

Questions come from the lessons behind this practical, so nothing is asked that has not been taught.

Quiz

Teeth, digestion and food chains quiz

6 questions from the lessons in this stage. No timer, and you can try again as many times as you like.