DNA: the instructions inside you
Every living thing carries a set of instructions called DNA. What it looks like, how it is written, and why people are all a little different. With a paper DNA ladder.
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Inside the cells of every living thing there is a set of instructions. They are called DNA.[2][1]
DNA looks like a very long, twisted ladder. Scientists call this shape a double helix.[2]
The instructions are written with only four letters: A, T, C and G. A always holds hands with T, and C always holds hands with G.[1]
Children get half of their DNA from each of their two biological parents. That is why a baby animal looks like its kind: a kitten grows into a cat, not a dog![4][1]
The DNA of all people is almost exactly the same. The tiny differences help to make each person look different.[2][3]
Try it: Build a paper DNA ladder
You need
- Two long strips of paper (the sides of the ladder)
- Small paper rungs in four colours: red, yellow, blue and green
- Glue sticks
- Felt-tip pens
Safety
Use child-safe glue and round-ended scissors if the rungs need cutting. Wash hands after gluing.
What to do
- Write A on the red rungs, T on the yellow rungs, C on the blue rungs and G on the green rungs.
- Remember the rule: red A always goes with yellow T, and blue C always goes with green G.
- Glue a red A on the end of one side. Which colour must go next to it on the other side? Glue it on.
- Keep going until you have made 8 rungs. Ask a friend to check that every rung follows the rule.
- Hold the top and bottom of your ladder and gently twist it. Now it looks like a double helix!
Play: Has DNA or not?
Living things have DNA in their cells. Is each thing alive with DNA, or not alive? Pick the box.
Your best score is kept only on this device. Nothing is sent anywhere.
Quiz
Other ages: Ages 10–11 · Ages 15–16