DNA or Deoxyribonucleic acid is a chain of organic molecules that caries unique genetic code and instructions which are necessary for any organism and even some viruses to evolve. They live in almost every cell of our body.
The discovery of DNA, its structure and characteristics is perhaps one of the greatest achievements in the human history. Not only it enabled researches on many genetic diseases, but helped explain other complications in the human body and whether a person invulnerable to any disease in the future.
Here, we have compiled a list of 26 intriguing facts about DNA that you must know. Let’s get started.
26. What does it mean when someone says human genome? Well, the human genome is basically the entire sets of base pairs of deoxyribonucleic acid or DNA (3 billions of them) that are embedded in all the 23 chromosome pairs in humans. The genome includes both coding and noncoding DNA.
25. There are only a few minds still alive who can effortlessly explain the workings of cosmos to a laymen more effectively than the enigmatic Carl Sagan. Here he explained the nature of human DNA and what its future looks like.
According to him, the nitrogen bonds in our DNA are made in an exploding star.
The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff. –Carl Sagan
24. The widely acclaimed human genome project was an advanced science research project that was carried out by an international group of researchers. The main aim of this project was to identify the correct sequence of base pairs in human DNA and map all the human genes.
The enormity of this project makes it one of the world biggest collaborative research. It ended in 2003.
22. Forensic experts and researchers have already developed an advanced forensic tool called “touch DNA“. It’s a revolutionary method that only requires minimal sample to effectively procure a DNA sample from a crime scene. However, this method has been a subject of severe criticism due to its high false positive results.
21. Do you know how many bacterial groups are there in the English Stilton blue cheese? Well, a group of British researchers found out there are at least 6 different groups of microorganisms present in the cheese that also play a role the distinct flavor of the cheese.
They were able to reach this conclusion after studying its DNA with denaturing gradient gel electrophoresis or DGGE.
20. According to a genome research back in 2011, men have somehow lost a DNA sequence that triggered penile spines. The study also revealed more than 500 DNA codes that are now missing from our body.
19. It would take anyone about 50 years to type down the entire human genome by the rate of 30 words per day for 16 hours a day.
18. Mutations are caused by permanent modifications in DNA sequencing. While genetic mutations generally take place during the DNA replication phase (especially meiosis), exposure to radiation, substance abuse and few other things can also lead to mutation.
An overview of meiosis Image Courtesy: Wiki Commons
17. Genetic mutation doesn’t always have a visible effect or any effect at all. These are called silent mutations. Other mutations, on the contrary, can compromise gene function or completely incapacitate gene.
16. If we try to measure the length of the entire DNA in our body from end-to-end, it would stretch from Earth to Sun and back 4 times or maybe more.
15. The Braconid wasp belongs to a family of parasitoid wasp that secretes a distinctive immunosuppressive virus along with venom. They use this virus to penetrate the host’s body in order to lay their infected larvae. The components of this virus are embedded in the DNA of Braconid wasp. Researchers have now traced its origin to a 100 million year old infection.
14. Human Chimerism is an extremely rare genetic condition that takes place during the initial stages of pregnancy. When pregnancy starts out with twins, sometimes one of the fertile eggs is absorbed by another during their microscopic phase. Normally, it doesn’t lead to any future complications.
However, in some exceptionally rare cases, the one that absorbed another egg also embrace its genetic code. As a result, after birth the person ends up having two totally different DNA in their body. There are only a few documented cases of human Chimerism in the world.
13. We share about 50% of our genetic code with bananas. But that doesn’t make us very close to bananas.
12. Nucleotides are the basic molecular units which are essential for the formation of nucleic acid; DNA and RNA. Nucleotides are in turn made of three types of molecules, one of the following four; cytosine, adenine, thymine and guanine (nitrogenous bases), deoxyribose or ribose (carbon sugar) and one Organophosphate or phosphate group.
Chemical structure of DNA Image Courtesy: Madeleine Price Ball
11. We are all related. Years of DNA research have concluded that every human being on Earth have about 99.5% genetic similarity with another human. It means that there is only 0.5% variation in individual DNA. On the other hand, we share about 98% DNA with chimpanzees.
10. Are you confused how we have a genetic variation of just 0.5%? Our genome contains approx. 3 billion of base pairs (nitrogen bases) and a difference of 0.5% makes it about 15 million distinct base pairs. That amount enough to impact diversity.
9. Do you know storing coded messages in DNA was first achieved in 1980s, however the technology available at that time was not capable enough to put anything more than few graphical signs. But in 2012, a group of researchers at the Harvard University were able to store 700 terabytes of information into a tiny, one gram of DNA.
8. Matured red blood cells in mammals, including humans lack cell nucleus, hence DNA. In fact RBCs are the only cells in the human body that doesn’t have DNA. However, other vertebrates have nuclei in their red blood cells with some exceptions.
Though red blood cells of birds have nucleus, they are mostly absent from the mature blood of female Gentoo penguin
7. It has been estimated that about 1 million DNA molecules are destroyed and repaired each day. Lack of effect DNA repair can lead to serious disease including cancer and other rare illness.
6. Do you know about 8% of our DNA is made of up of retroviruses that infected us thousands and thousands of years ago? Yes, that’s right. Retroviruses target other cells by inserting their own DNA into the host cell’s genome. They can also be inherited by offspring naturally through sperm or an egg.
Researchers now believe that there are substantial amounts of retroviruses present in our DNA that ceased replicating or functioning long ago. But, in 2007, a team of researchers successfully activated one of those retroviruses.
5. The fact that DNA carries the genetic information was discovered by researcher Oswald Avery Jr. in 1944.
4. James Watson is widely regarded as the co-discoverer of the structure of the DNA molecule along with his fellow researcher James Crick for which they received the Nobel Prize in Medicine in 1962.
However, their discovery is fundamentally based on exceptional works of Raymond Gosling, Maurice Wilkins and particularly Rosalind Franklin. While Wilkins was also one of the recipients of the Nobel Prize in 1962, Rosalind Franklin died before she could possibly receive the prize.
Maclyn McCarty with Francis Crick and James D Watson Image Courtesy: Marjorie McCarty
3. DNA has a half life of 521 years. It means that half of the bonds between nucleotides would have broken after 521 years (after cell death). Over the next 521 years, half of the remaining bonds would wear out and so on.
At this rate, every DNA bonds would be destroyed after 6.8 million years. This discovery was made by a group of international researchers back in 2012.
2. Swiss born biologist and physician Friedrich Miescher became the first ever person to isolate nucleic acid in 1869. While experimenting on leukocytes (white blood cells), he stumbled upon a completely unknown substance which he initially thought was some sort of protein.
Further analysis of the substance, revealed that unlike protein, it contained large amounts of phosphate-rich chemicals. His discovery was however not clearly understood by the scientific community until 1870s.
Experimental Setup of Photo 51 and the sample Image Courtesy: Derived work based on geograph.org.uk by Robin Stott
1. The Photo 51 was perhaps one of the most important evidence in determining the actual structure of DNA. It’s an X-ray diffraction image of DNA taken by researcher Raymond Gosling and Rosalind Franklin at King’s Collage, London in 1952. The image provided crucial details about the nature of DNA structure; the double helix.