very confused as to what DNA is, and have no technical expertise to understand detailed articles! Is DNA something you can look at under a microscope or what?
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DNA is like a book that every living thing has inside their cells. It’s a book that tells your cells what to do, how to replicate and how to form you. Every living thing has DNA and by using chemicals and expensive lab equipment scientists can pull that “book” out of your cells and read it.
After we die all the materials and cells that make-up our body start to break down and that includes the DNA “book” we have inside. However, sometimes depending on how our bodies were preserved when we died, that book can last a really long time. Bones are not an especially good place to get DNA from but sometimes people can find preserved tissue inside them which you can extract DNA from.
More like, explain like I’m 10: Technically you can see DNA under a special microscope in the form of chromosomes. They’re just a super super dense wound up DNA strand. DNA is a physical chain made up of nuclei acids. As for the extraction:
https://set.adelaide.edu.au/news/list/2021/10/12/can-we-extract-ancient-dna-from-dinosaurs
This explains it pretty well. hope it helps
DNA is just a special kind of polymer that is contained in your cells. A polymer is a chain of molecules that are stable on their own, (monomers) but which are also stable attached to themselves in a chain (polymers). There are all kinds of polymers in your fmday to day life. Almost all plastics for example. Polyurethane and epoxy resins are both examples of taking a liquid made of many monsters that aren’t connected yet, adding a catalyst to speed up the connecting process, and then making the liquid into a shape before all the connecting polymers form and make it solid.
DNA is a special kind of polymer where instead of being the same monomer repeated over and over again, there are four different possibilities. The order in which these four substituent monomers occur is how DNA stores information. Usually, in patterns of three.
There are special indicator chemicals which you can apply to test samples, which react with DNA without altering its structure. There’s a LOT of very chemistry involved, but, essentially, the mechanism is very similar to how proteins are folded. Essentially, it balls the DNA up very tightly, and makes it possible to encapsulate the DNA strand. The indicator chemicals are also combined with other special chemicals that are used to cause the DNA and the indicator to be able to dissolve into a solution that leaves everything else behind. So, you essentially are washing the DNA off with a social chemical that only washes away DNA.
Then, the DNA sample is separated from everything else and can be examined using other techniques like genome mapping or gram staining. Obviously, the DNA is severely damaged but if you know the “rules” for how the DNA syntax works, you can look at the surrounding information for a section of DNA and determine what a small missing piece is based on whether or not it makes sense for anything else to be there. Remember what I said about chunks of three? While there are technically 64 unique combinations of 4 things three times, only about 30 of them get used, and often if you know two of them, there are only one and rarely two other possibilities for the third.
There are all kinds of fascinating techniques for figuring out what the missing parts of a DNA strand are
DNA is a molecule made up by smaller molecules. It’s in a double helix shape, imagine like a spiral staircase 🧬. DNA is wrapped up into even bigger molecules called chromosomes, which are then stored in the nucleus of every cell in your body.
DNA is basically the blue print for life. It acts like a code made up by 4 letters: ATGC. They are massive strings, billions of letters. Fun fact, if you string all the DNA from all chromosomes from just one cell into one continuous string, you’d get a string 2 meters long. So there’s a lot of instructions. You share a lot of DNA with other people and other kinds of life. But the stuff that makes you unique, your appearance and size and stuff, is a bit of code that’s only found in your DNA.
When they check bones for DNA, they cut it open and get to the marrow. Here there’s some remnants of cells with fragmented DNA still intact. They use computers to puzzle it back together, and with a little luck, you get the unique bits of code that you can use to identify ethnicity, sex and sometimes even a specific person. But DNA is pretty much broken down after 10000 years so you can’t bring back cave people or something like that 😉
DNA extraction from super old bones is a tricky process, but it’s possible! Scientists first have to find an ancient bone that is well-preserved. Then, they have to clean the bone to get rid of any dirt or bacteria that might be on it. After that, they use a special solution to dissolve the bone into small pieces. They filter out the pieces and collect the DNA. Finally, they use a technique called PCR (polymerase chain reaction) to make the DNA strands visible so they can analyze it.
DNA is a molecule that records the patterns that make the proteins that make up everything in your body. It’s a long and *extremely* tough molecule, as these things go, and has a lot of built in redundancy and repetition in its patterns as well. DNA can survive intact for a long time in good conditions, and even in bad conditions it takes a lot to break it down to the point where we cannot put it back together again, using those patterns and redundancy as a guide.
Imagine a book – if all the pages are ripped out, you can still put them back in the right order, using the page numbers. If half the pages are missing, it takes more work, but you can still have a good guess at the right order, and get a sense of what the book was about. When you try to examine very old bones for DNA, it would be like a book run thru a shredding machine, tiny fragments all mixed up – but still extractable, and with a lot of patience and technique, still able to be put back together.
DNA is a molecule that’s a really long chain made up of smaller units called nucleotides. It’s like a string of pearls with four colors (for different nucleotides). The sequence is used as a template to build all the proteins of the body, and guide the development of a single cell into a fully formed mature living thing.
You can’t see DNA under a normal microscope. Sometimes you can see chromosomes where DNA is wrapped around nuggets of protein, but DNA itself is too thin to see without a special type of electron microscope.
To get DNA from old bones, you scrape out some of the bone marrow and soak it in clean water. Then you mix some chemicals in that makes it break free from other crud that might be there. Then you have bits of DNA floating in the water (which you can’t see).
Once you have a bit of DNA, you can make copies of it. All cells have enzymes that can make copies of DNA, and you can now buy those from chemical suppliers. So, you use enzymes to make many copies.
Then, you “sequence” the DNA. It’s a chain of pearls with different colored pearls and there’s all sorts of ways of chemically figuring out what that sequence is, either by plucking one base at a time off, or adding one on. We “see” the base that’s plucked off using specially designed machines that can “read” the chemical signatures (there are many different ways).
You sequence lots of small pieces many times, so you have lots of sequence fragments. We represent their sequences as strings of the letters A, C, G, and T representing the four nucleotides forming the DNA chain (adenine, cytosine, guanine, and thymine). Then, you use computers to line up the fragments (which overlap each other) and stitch them together like a puzzle to reconstruct the larger original sequence. We can even recognize if the sequences come from contamination like bacteria.
Given the sequence, we can identify diseases, traits, compare it to different people groups to identify ancestry, link it to descendants, detect many diseases, etc.
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