The Scientific Art of Identity
An Introduction to DNA for teachers to use

DNA introduction
What do all these sayings/idioms/expressions mean?
• ‘I’m a chip off the old block’
• ‘like father, like son ’
• ‘she’s got her mother’s eyes’
• ‘they’re like two peas in a pod’
= how we inherit certain features from our parents – all to do with our ‘genes’ (not ‘jeans’!) Ask the children to talk round these issues
Like two peas in a pod
When/where have you heard term ‘genes/genetic’ before?
(brainstorm eg genetic engineering, fingerprinting, Gm food – genetically modified, genome project, cloning eg Dolly the sheep)
S how images of Dolly and articles on GM food. ask children to talk round these issues.
What is DNA?
This stands for – show words to the children on a card. Ask children to repeat the words and say them. Click to hear children saying deoxyribonucleic acid
Now show Russian dolls and use them to demonstrate:
ORGANS – CELLS - NUCLEUS – 46 CHROMOSOMES (23 PAIRS) – TIGHTLY PACKED DNA MOLECULES - GENES = about 30,000 genes in every human cell (less than originally thought)
Russian dolls are a good way of showing the relationships between organs, etc and genes

If all our DNA were unraveled, it would spread from Earth to the sun (29, 000,000 miles) 30 times!

Show video tape in case = like a chromosome
Blank tape inside = DNA molecule
Recorded tape = genes = instructions or code
Use a video tape to show the relationship between chromosomes, molecules and genes
DNA molecule = 2 strands of sugar & phosphate, linked by nucleotide bases, like a twisted rope ladder.
Bases pair up to make rungs (adenine & thymine, cytosine & guanine)
Make cards with letters on them and give these to the children - A – T / C – G Give out ½ of CTAG cards randomly. Ask them to find a matching pair, then repeat this, but not the same sequence, without moving too much, so they are like a dna spiral

A rope letter is a good prop for these examples

Children finding their matching pairs

Variation in this code, makes each unique person (apart from identical twins which are genetically the same, although they do have different fingerprints)
Why might some identical twins be easier to tell apart? – due to environmental factors eg how much food they eat, exercise, haircut etc
Variation in code rather is like 8 musical notes – arrangements make Beethoven – rap!

98% of our DNA is the same as a chimp’s show images
55% same as a banana!
Every human being on the planet is 99.9% the same!
Humans are 55% genetically the same as a banana

BUT…
Sometimes instructions go wrong eg changing 1 letter in a word totally changes its meaning & function in a sentence – nice, mice rice – same with genetic code
1 baby every ½ hour is born with a genetic problem
4000+ different genetic disorders, some more serious than others, some affect us in later life