One of the most incredibly important discoveries in scientific research and history is the discovery of DNA.
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The discovery of this unique molecule is what birthed a whole new science-based around heredity and eventually genetics, and its secrets are still only being discovered and unlocked now, 150 years since its first discovery.
Like many of the most significant scientific discoveries, the knowledge is so new and revolutionary that it takes many years for the importance and usefulness of a discovery to sink in, and the people of the 19th century and early 20th century had no idea how revolutionary this single-molecule and discovery could be to humanity, from its medical applications to its uses in fighting crime to modern genetic modification and farming techniques!
In this guide, we’re going to do a rundown on DNA, from the meaning of those three letters to some more history and detail surrounding DNA as well
What Do the Letters Stand for?
The letters DNA stand for Deoxyribonucleic acid, and this essentially refers to the shape and content of the molecule, however, the full name is… quite a mouthful so it’s shortened to DNA for clarity and ease of use.
The name mainly refers to the structure of the molecule, which is made up of a sugar and phosphate group which forms the backbone of the molecule, with bases sticking out of it.
The “deoxyribo” part of the name refers to these sugars, and the nucleic acid symbolizes the phosphates and bases that comprise the rest of the molecule.
Despite the complex-sounding name and famous double helix structure of DNA, the molecule is actually incredibly simple, which is amazing as it contains all of the instructions our cells need to function properly, which is a testament to the marvel that is the human body and evolution itself.
What is DNA?
In real terms, DNA is the package that contains all of the instructions to make… well, you, or indeed any living thing, even the tiniest single-celled organisms!
DNA is in all humans and almost all organisms.
Almost all human cells in a person’s body have the same DNA, and the DNA is stored in the nucleus of these cells, which forms the center of each cell and is where the instructions for the cells are located.
There is a small amount of DNA found in mitochondria cells, however, which is called mitochondrial DNA or mtDNA, and is a slightly separate molecule to our main DNA.
The instructions and information stored in our DNA form a code which is made up of four chemical bases, known as; Adenine (A), Guanine (G), Cytosine (C), and Thymine (T).
The organization of these bases and the number of them dictates how complex an organism is, and as an example, human DNA contains some 3 billion bases, and the reason for the large similarities between most humans is that over 99 percent of these bases are identical in all people.
Relatives will have an even higher number of similarities in these bases, and just a few key changes here can make a huge difference to the appearance, form, and function of an organism, which is why DNA and genetics are so powerful and dangerous.
These minute differences in DNA are also what allow us to trace it and use it to identify people with incredible accuracy.
DNA is almost always unique to the person it belongs to, and while close relatives and family members will have very very similar DNA, there will almost always be tiny differences that make identification and tracing possible.
Who Discovered DNA and How!?
In 1869 a Swiss physician named Friedrich Miescher was the first person to study the substance that would eventually become known as DNA.
He noticed that there was a microscopic substance inside the pus that was left on used medical bandages, and was struck by the strangeness of this occurrence.
He initially named the substance Nuclein as this strange discovery was found in the nuclei of the cells, which at this time were known to scientists as a key part of the cellular structure.
However, the importance and nature of the discovery didn’t become apparent for some time.
It didn’t take very long however for DNA to be confirmed as the source of genetic heredity, and this was confirmed in 1952, less than a hundred years later than its initial discovery.
In 1953, two scientists named Francis Crick and James Watson discovered the now-famous double helix shape of DNA and notoriously claimed that they had “discovered the secret to life.”
All modern genetic science has stemmed from these discoveries, such as the famous Human Genome Project which ran in the late 90s and early 00s, and other key genetic science such as crop manipulation and STEM cell research.
Where Does DNA Come from?
As mentioned before, DNA is found in the nucleus of all organic cells and dictates the form and function of these cells.
However, in a broader sense, DNA comes from your parents! Half of your genetic makeup comes from your mother and a half from your father, or your biological parents if you’re someone who was born via in-vitro fertilization.
This means that almost all your genetic material has been passed down through the generations, which is why family traits are so similar and passed down, from the shape of your nose and eyes to your skin color and even diseases and ailments.
There can be mutations and changes, however, and this is what leads to evolutionary adaptation.
How Much DNA do I Get from Each Parent?
You get half your DNA from one parent and a half from another, usually a biological male and female.
The genetic traits that are expressed can be a mixture of these depending on whether the traits are dominant or recessive and there is competition between these traits to determine which genes are expressed and which are dormant.