DNA is fascinating and incredibly important. Our bodies have over 200 types of cells, all designed for different functions. It is DNA which provides the instructions, basically telling each cell what to do. The DNA in our bodies, is stored in 46 chromosomes, in the nucleus of our cells. In order to fit it all the DNA in, enzymes are used to help coil it all up so it takes up less space. Each strand is thousands of times thinner than a single strand of hair. However, there is a lot of it! If we could stretch out the DNA in just one cell – it would be around 2 metres long! Strangely – an amoeba, a tiny single-celled organism, has about 100 times more DNA than we do. It can have more than 500 chromosomes in a single nucleus.
Not all animals just follow the instructions of their DNA. Squid and octopus can edit and direct their own genes! Sometimes they interfere with the code, which changes the proteins their cells produce. This, in turn leads to interesting variations in their behaviour, and is, scientists believe, what could be responsible for their complex behaviour and high intelligence!
GCSE scientists – you need to be able to explain the structure of DNA. For help, try our new guide “How to work with DNA”. It includes a description of its structure. In addition there is information on how to extract it from fruit. As always there are questions to try, and answers to check your understanding.
Click on the picture below to see the guide.
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