BIGGEST EVER MATHS & SCIENCE LESSON

GUINNESS WORLD RECORD ATTEMPT

www.bubblymaths.co.uk/DNALesson maths@bubblymaths.co.uk

INSTRUCTIONS for BALLOON MODELS OF THE DNA DOUBLE HELIX The kit is sufficient to make three 10 rung models of the DNA ladder, each 120 cm long, and to split one to show how DNA replicates itself. You will then have four models. The kit includes spare balloons to replace those that pop or are not measured correctly. The DNA double helix twists through 3600 over 10 rungs. When you twist your models each 10 rung double helix will measure about 90 cm. CONTENTS OF KIT • 100 white 260 balloons • 30 green, 30 red, 30 blue, 30 yellow 260 balloons • 1 balloon pump • Instructions Making one model will involve up to 40 learners each taking an active part. A trial run will give you a good idea of what the task involves for the learners and help you to be aware of the difficulties. To try it out, you could make the first model yourself, or with other adults, then you could rehearse it with the class in advance and finally, on the BIG day, the learners make the third model. List of requirements: • 2 sealable black plastic bags (black to protect the balloons from light - balloons are made from rubber tree sap. They

are biodegradable and they last longer in a cool, dark place.) • Two large boxes or baskets, capacity about 50 litres, for example a box 30x30x50 in centimetres or12x12x20 in inches. • Scissors • 15 cm rulers (30cm rulers are OK), one for each pair of learners.

INSTRUCTIONS FOR MAKING THE MODEL Watch the video about the preparation needed before the lesson on www.bubblymaths.co.uk/dna-lesson-resources You will use 14 white balloons, 4 red balloons, 4 green balloons, 4 blue balloons and 4 yellow balloons. You will need to cut the balloons in 3, knot the open ends, and inflate them before the lesson. Each balloon that comes in the kit makes three 15 cm balloons.

The preparation takes between 90 minutes and two hours. Each 10 rung model takes 20 coloured (15 cm) balloons and 22 white balloons and involves up to 40 learners taking an active part. This works well for smaller classes of 30 learners or fewer with some learners making more of the parts which are assembled to make the model. To make a 10 rung model start with 2 containers to put the 15 cm

balloons in when you have inflated them: (C1) 20 white, 5 red, 5 green, 5 blue and 5 yellow

the white balloons make the sides (or back bones) of the DNA ladder, the coloured balloons make the rungs (bases) of the ladder

(C2) 22 white, 5 red, 5 green, 5 yellow, 5 blue SPARE balloons ready to replace any balloons that pop or are not the right size

For detailed instructions for making the model watch the video on www.bubblymaths.co.uk/dna-lesson-resources The learners should work in pairs for this activity. The teacher must ensure that each pair has a 15 inch ruler and one white and one coloured balloon from container (1). Method: 1. Push air to the end of balloon to make a bubble 2 cm in diameter. Squeeze and twist. Hold the twist or it will pop out. Make sure that everyone has a bubble at one end of their balloon and a small un-inflated tail at the other end.

BIGGEST EVER MATHS & SCIENCE LESSON

GUINNESS WORLD RECORD ATTEMPT

www.bubblymaths.co.uk/DNALesson maths@bubblymaths.co.uk

2. Pairs of learners - twist their two spherical bubbles together. Each pair now has A NUCLEOTIDE with one white “back bone” and one coloured base molecule. 3. The pairs that finish first can make up more nucleotides until container (1) is empty 4. When all nucleotides are made: Learners with a yellow nucleotide find a pair of learners with a blue nucleotide Learners with a red nucleotide find a pair of learners with a green nucleotide 5. MEASURE a 10cm length of balloon on the coloured balloon. Squeeze and twist. HOLD the twist. Check the length. It is very important to get this measurement correct. JOIN the red and green balloons together JOIN the blue and yellow balloons together 6. You now have 10 rungs ready to join together to make the model of the DNA ladder by joining the white balloons to make the two sides of the ladder. MEASURE a 10cm length of the white balloons. Squeeze and twist. HOLD the twist. Check the length and repeat if it is not exactly 10 cm. 7. Make a line of the 10 “rungs” at the front of the class. One learner holding each white bubble. The teacher should go along the line to supervise the process of joining up the edges of the ladder. It usually works best to make one connection at a time with the teacher to assist if necessary. Start at one end…. • Measure 10 cm on the white balloon, make a bubble at the free end, and join it to the next rung where the white and

coloured balloons join. Twist all three bubbles together. • Join the next rung to the chain in the same way. • Continue until you have a 10 rung ladder. 8. The ladder will have two white balloons free at one end and not at the other end. • One learner can hold the free white balloons “handles” at one end. • To complete the ladder two other learners should:

ü each collect another 15cm white balloon, ü squeeze air to the end and twist to make a 2cm bubble, ü hold the twist, ü attach to the end of the DNA model. ü One learner should now hold these 2 ‘handles’ that have just been added.

9. Make sure all the bubbles are tidy and the “ladder” lays flat. • Where 3 bubbles join, put the white bubbles on the outside and the coloured bubble in the middle. • At the centre of each rung put one bubble on the front and the other directly behind it on the back. Put the coloured

bubble of the left hand base on the front and the coloured bubble of the right hand base on the back. 10. Measure the length of the ladder by measuring the distance between the handles held by the learners at each end so that the ladder is as long as it will go without being stretched. 11. The learner holding the handles at one end of the ladder should rotate the ladder by 180 degrees clockwise and hold it. • Both learners should move closer together as the ladder twists. • What is the distance between them now? • 2nd learner at the other end should rotate the ladder by 180 degrees clockwise and hold it. • Again, both learners should move closer together as the ladder twists. • What is the distance now? You have to judge what looks right. It should be about 90 centimetres.

You have now made a model of a 10 rung double helix DNA ladder with a 360o rotation. CONGRATULATIONS! Take lots of photos! We shall make a composite photo joining all the DNA ladders from all the photos submitted. Get all learners BEHIND the DNA strand as learners at the side may be cropped off. Take photos from 3 metres away from DNA strand making sure that the four white ‘handles’ are visible. The photo and exact numbers of learners and teachers involved, together with the address of the school, must be submitted to http://www.bubblymaths.co.uk/ by Thursday 5 November at the latest. Schools will get a free certificate from AIMSSEC, Bubbly Maths & HeyMath and a template to print certificates for each learner who took part. We hope to achieve a Guinness World Record and feature in the Guinness World Record Book.