This week, Topla is offering you the chance to play private detective! Discover what determines a person's UNIQUE identity: their DNA. Chromosomes will soon no longer be a secret to you! Let's go for a little investigation into what makes you unique in the world.

Material :

• 4 felt-tip pens of different colors
• 1 sheet of paper
• 1 rule
• 1 pencil
• scotch tape

Step 1

Start by dividing your sheet as shown in the picture. Measure 9 cm on the sides and make marks every 1.5 cm. Along the length, each rectangle measures 5 cm.

These measurements are only indicative, you can draw rectangles with other measurements!

Step 2

Cut out your small rectangles and choose 2 pairs of colors: we chose to combine purple-yellow and blue-pink. Each color represents a chemical element that makes up DNA (They are called nucleotides, there are 4 different ones).

Step 3

Spread 2 long strips of tape, sticky side up. Place your nucleotides in any order on the two strips of tape, as shown in the picture. You are creating a unique piece of DNA! Be careful to leave a blank space of tape above each nucleotide.

Step 4

Fold the tape over itself to keep the nucleotides securely in place.

DNA is a kind of "identity card". This code, contained in the cells of your body (in fact, very precisely on your chromosomes!) is transmitted by your parents. It determines all your physical characteristics: for example the color of your hair, your height etc. ..

Step 5

Wrap your piece of DNA around itself to make it into a helix shape.

A DNA molecule is made up of two strands joined together that twist together to form a helix. This form of double helix was discovered by scientist Rosalind Franklin .