Containing over three billion cells - each with a specific job to do - your body is a wonder to behold. Learn how it works, by creating your very own liquorice double helix (DNA), laced with gummy bear bases!
Some cells help us to see, others give us our sense of taste or touch. Other cells allow our bodies to jump, or run, or blow a bubble, or throw a ball. But how do the cells know which job to do? The answer is found in DNA: the body’s very own blueprint or instruction manual. Take your child on an adventure into the unknown with this fun, tasty STEM activity.
- Begin by talking to your child about DNA.This video is a great place to start.
- Gather your sweets. To make the sugar and phosphate sides, we recommend using strands of black and red liquorice. For the nitrogenous bases, we recommend using gummy bears. If you choose different sweets, ensure they’re soft enough to puncture with a toothpick.
- Gather some string and at least a dozen toothpicks.
- Cut the string to around a foot long.
- Cut the liquorice into individual pieces, measuring around one inch each.
- The four letters of the DNA alphabet are similar to pieces of a jigsaw puzzle. Cytosine and guanine (C and G) fit together, while thymine and adenine (T and A) fit together. Choose four different colored gummy bears to represent these nitrogenous bases, and help your child to pair them up accordingly. It doesn’t matter if a pair goes C–G or G–C, as long as those are always the two in a pair. However, just as certain pieces of a mismatched jigsaw simply cannot fit together, certain base pairs simply cannot be mixed (e.g T–G and A–C cannot be combined).
- Take the two pieces of string and tie a knot in the bottom of each.
- Thread the string through the hollow centers of the liquorice in alternating colours. These symbolise the sugar and phosphate that make up the double helix strands.
- Once you’ve added all of your liquorice pieces, tie another knot at the end of the string.
- Pair off all the gummy bears into the C–G and T–A groups and stick them on the toothpicks – one pair per toothpick. Push the gummy bears into the middle of each toothpick, so there is a little space on each end of the toothpick.
- Lay out your two liquorice strands on a smooth surface. Attach the gummy bear toothpicks to both strings of liquorice, by inserting the sharp ends of the toothpicks into the liquorice, joining the strings together to form one DNA strand.
- Once you’ve attached your toothpicks to the liquorice, twist the strands in a counterclockwise direction. This will create the spiral appearance of a true double helix.
What is DNA?
DNA – also known as Deoxyribonucleic acid – is a molecule; a bunch of atoms stuck together. In the case of DNA, these atoms combine to form a ladder, known as the double helix.
What does DNA do?
DNA contains genetic information that acts as a blueprint or ‘recipe’ for all living things. It’s a code for what our body needs to make to survive, such as proteins, enzymes and hormones. Our genetic code influences many of the things about us – such as how we look, how we behave (to some extent), and how likely or unlikely we are to suffer from particular ailments and genetic diseases. Though our environments also shape who we are, our genes are fundamental.
Fun facts about DNA
- Nearly 2 metres of DNA is located in the nucleus of every cell in our body!
- Our DNA is organized into chromosomes. When we are conceived, we receive 23 chromosomes from each of our parents: that’s 46 in total.
- If you unraveled all the DNA molecules in your body and placed them end to end, they would stretch to the Sun and back several times.
- Astonishingly, every person’s DNA is 99.9% similar to that of another person! It’s the variations within that 0.1% that give us our unique DNA fingerprint.
- We also share many genomes (an organism’s complete set of DNA) with other species. For context, according to most estimates, the chimpanzee genome and the human genome are 98.5% similar. Just think of all the seemingly large differences between us, and the startling similarity of our code. It’s very interesting indeed!