Sophie is the first winner of our science writing competition, and entered the 10-12 year old category. She is 12 years old and from the UK. Sophie’s piece is all about our DNA and how it can be used to identify us. It was a wonderful read, and very impressive for someone so young. Congratulations Sophie.
DNA: What it says about you?
Have you ever wanted to know who stole your pen in class last week? Or who robbed the bank that your uncle works at? To be able to find all of this out everyone has their own DNA, which enables people to distinguish one human from another. Evidence can be gathered by taking samples from any crime scene such as: fingerprints, hair samples, saliva and much more.
I feel so connected to DNA because I like to find out about the past and I’ve always wanted to see what my past family members were like and what features I’ve inherited from them. My personal DNA allows me find this out. Also, when I was younger I lost one of family members and to see who did this, the police needed suspect’s DNA. So here is some history about DNA and further on in my blog I will explain more in depth information about how DNA is formed and where is it in the body, leaving you with a more extended knowledge of DNA.
Each cell in the human body contains about 2 meters of DNA that’s packed into a tiny nucleus that’s only about 5 micrometers in diameter. DNA, short for deoxyribonucleic acid, is a complex molecule that contains all the information necessary to build and maintain an organism. DNA is made up of molecules called nucleotides. Each nucleotide contains a phosphate group, a sugar group and a nitrogen base. The four types of nitrogen bases are adenine (A), thymine (T), guanine (G) and cytosine (C). Human DNA is 99.9% identical from person to person. Although 0.1% difference doesn’t sound like a lot, it represents millions of different locations within the genome where variations can occur, equating to a breathtakingly large number of potentially unique DNA sequences.
Many people believe that American biologist James Watson and English physicist Francis Crick discovered DNA in the 1950s. In reality, this is not the case. Rather, DNA was first identified in the late 1860s by Swiss chemist Friedrich Miescher. Its little structure was first identified by Francis Crick and James Watson at the Cavendish Laboratory within the University of Cambridge in 1953, whose model-building efforts were guided by X-ray diffusion data acquired by Raymond Gosling, who was a post-graduate student of Rosalind Franklin. Having just completed his education as a physician, Miescher moved to Tübingen (Germany) to work in the laboratory of biochemist Hoppe-Seyler, his aim being to clear up the building blocks of life.
To form a strand of DNA, nucleotides are linked into chains. In organisms called eukaryotes, DNA is found inside a special area of the cell called the nucleus. Because the cell is very small, and because organisms have many DNA molecules per cell, each DNA molecule must be tightly packaged. This packaged form of the DNA is called a chromosome.
Weird Facts about DNA
- If unwound and linked together, the strands of DNA in each of your cells would be 6 feet long. With 100 trillion cells in your body, that means if all your DNA were put end-to-end, it would stretch over 110 billion miles. That’s hundreds of round trips to the sun!
- Genes make up only about 3 percent of your DNA.
- We share 96% of our DNA with primates such as chimpanzees, gorillas and orangutans. But we are also genetically related to bananas – with whom we share 50% of our DNA – and slugs – with whom we share 70% of our DNA.
- 8% of human DNA is now made up of ancient viruses that used to infect us and make us ill.
- The DNA in every human cell gets damaged over 100 times a day, however, our bodies have very clever systems in place to act as repairmen.