1. Human Variation
We’re all different from one another whether it is through our DNA, our fingerprints or other physical features. Forensic scientists use these physical differences to try and identify people. We can use different parts of the body to do this. For example, from a person’s hands, we can look at their fingerprints or their knuckle creases for similarities and differences.
During week 6 you learnt that the similarities and differences between you, your family and everyone else are determined by your genes. Genes are made up of DNA (can you remember what DNA is made up of?). Sometimes we leave DNA behind – we might leave it when we drink from a cup or on a door we’ve touched. Forensic Biologists can compare DNA from a crime scene to determine if it is the same as the DNA from a particular person. To do this they need to collect the DNA, extract it from the cells that contain it and then analyse the extracted DNA. DNA profiles look like peaks on a graph where the combinations of different groups of peaks are different for different people.
You can extract your own DNA at home so that it is visible to see in today’s activity.