DNA is now a part of everyday language, but how much do we really know or understand about it? What does it tells about each of us? Understanding DNA in 10 minutes might seem tricky but it’s not impossible. Tom Ireland of Focus University has written a potted explanation and all most of us need to know.
Introduction to DNA
In 1953, geneticists Watson and Crick declared, “We have discovered the secret of life!” Since then the knowledge of and practical applications for DNA have increased each and every year. These two incredible scientists could not have said a truer word: DNA is the building block of all living things and can unlock the mysteries of how those living things make, replicate, and repair themselves.
DNA, which stands for deoxyribonucleic acid, is found in every cell of every living thing. It carries all of the instructions for an organism to build, maintain and repair itself. By replicating and passing on their DNA, animals, plants and microorganisms can impart their characteristics to their offspring. This is critical to the Darwin Theory of Evolution, and how the strong survive—by passing on their traits through their DNA.
Here are some of the basics, shared directly from Ireland’s article). Set a timer for 10 minutes, and…GO!
How Does DNA Work in Humans?
- In humans, half the DNA in our cells stems from our mother, and a half from our father, which is why we inherit a mixture of characteristics from both parents. DNA is a hugely long and complex code, and every one is unique. This “genetic code” can tell us many things, including details about the ancestry and potential health problems.
What are Genes?
- Genes are sections of our DNA sequence that contain the code for a specific protein, normally linked to a specific function or physical characteristic. In humans, for example, a stretch of DNA known as ‘OCA2’ has a strong influence on a person’s eye colour.
- Variations in these parts of our DNA lead to the different characteristics we see among individuals. For example, people with blue eyes have different DNA at ‘OCA2’ than people with brown eyes.
- A common misconception about genes is that one gene is responsible for one trait, which is actually highly unusual. More commonly, physical traits result from a combination of many genes.
How Does DNA Replicate?
- The discovery of DNA’s “double helix” structure helped reveal the beautifully simple way a DNA molecule replicates itself. With the help of other chemicals in the cell, the double helix untwists and the two strands split down the middle, like a zip. Strands are made up of nucleotides adenine (A), thymine (T), cytosine (C), and guanine (G). Because A always pairs with T, and C with G, both strands then form an exact copy as more nucleotides are attracted into the corresponding place opposite the freshly-split strands.
- The replication process is crucially important, because cells are constantly dividing and replicating. If DNA is copied incorrectly, the resulting cells have jumbled instructions and can start growing out of control. This is often how a cancerous tumor starts.
What Can We Do with DNA?
- We already use DNA for a range of immensely-useful applications such as home genetic test kits that can tell us about our past, present and future: who our ancestors are, what medicines we should take or avoid, and what illnesses we may develop many years from now.
- We can also use it to answer paternity questions, or catch criminals by analysing tiny amounts of DNA found at a crime scene.
- But that’s just the start. As DNA sequencing becomes vastly easier and cheaper, what was once unthinkable is now eminently possible. Already, scientists can create personalised medicines that are tailored to work with your exact combination of genes. They are reading the genomes of cancer cells, in order to learn more about them and fight them. Gene therapy can be used to fight genetic disorders by inserting new genes into people’s DNA.
- In the future, biologists may be able to create entirely new organisms that exist solely to produce useful products for us. We may even be able to edit the genome of our offspring—not only to guarantee our children are free from genetic disorders, but also to ensure they have the characteristics we want.
This fact sheet may not have turned you into a DNA expert, even if you have managed to read this in 10 minutes. But it does provide enough information to give you a fundamental overview of DNA, and hopefully, makes you eager to learn about DNA mysteries that are likely to be uncovered in the near future.
