DNA contains the genetic instructions for the development and functioning of a living organism. While there are billions of people in the world, each one unique , we actually share 99.9% of our DNA with each of them. The Human Genome Project , completed in 2003, confirmed that 99.9% of the 3 billion base pairs in humans were identical. That means just 0.1% of your genes is what makes you unique. And we are all a lot more alike than you may have imagined!
It is fascinating what your DNA can tell you. It can indicate what kind of medical conditions you may be prone to and inform you about your ancestry. You can even discover whether you are likely to have perfect pitch or smell asparagus!
Scientists extract DNA from saliva samples, and will look at it in hundreds of thousands of different places. This is then compared to the DNA of thousands of people in a database from all around the world. By checking for similarities in different areas, they can match you to groups of similar people. This can then indicate where your ancestors may have come from. Different parts of your DNA may be matched with different populations, showing you have ancestors from different parts of the world. Because thousands of years ago it was not easy to travel around the world, people were more likely to have children with their neighbours. This resulted in people sharing more DNA with people living nearby.
GCSE scientists – you need to explain how genetic information is passed on from parents to offspring. For help with this try our new guide “How to work with Genetics: Part 1”. It includes information on genetic diagrams and key vocabulary you need. It includes questions to try, and answers to check your understanding.
Click on the picture below to see the guide.
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