DNA: The book of you – Joe Hanson

Translator: Andrea McDonough
Reviewer: Bedirhan Cinar Every human being starts out the same way: two cells, one from each parent, found each other and became one. And that one cell reproduced itself, dividing, dividing and dividing until there were 10 trillion of them. Do you realize there’s more cells
in one person’s body than there are stars in the Milky Way? But those 10 trillion cells
aren’t just sitting there in a big pile. That would make for a pretty
boring human being! So what is it that says a nose is a nose, and toes is toes? What is it that says this is bone and this is brain and this is heart and this is that little thing
in the back of your throat you can never remember the name of? Everything you are or ever will be made of starts as a tiny book of instructions found in each and every cell. Every time your body
wants to make something, it goes back to the instruction book, looks it up and puts it together. So how does one cell hold
all that information? Let’s get small. I mean, really small —
smaller than the tip of a sewing needle. Then we can take a journey
inside a single cell to find out what makes up the book of you, your genome. The first thing we see
is that the whole genome, all your DNA, is contained inside
its own tiny compartment, called the nucleus. If we stretched out all the DNA
in this one cell into a single thread, it would be over 3 feet long! We have to make it fit
in a tiny compartment that’s a million times smaller. We could just bunch it up
like Christmas lights, but that could get messy. We need some organization. First, the long thread of DNA
wraps around proteins clustered into little beads
called nucleosomes, which end up looking
like a long, beaded necklace. And that necklace
is wrapped up in its own spiral, like an old telephone cord. And those spirals get layered
on top of one another until we get a neat little shape
that fits inside the nucleus. Voilà! Three feet of DNA
squeezed into a tiny compartment. If only we could hire DNA
to pack our suitcases! Each tiny mass of DNA
is called a chromosome. The book of you would have 46 chapters, one for each chromosome. Twenty-three chapters of your book
came from your mom, and 23 chapters came from your dad. Two of those chapters, called “X” and “Y,” determine if you’re male, “XY,” or female, “XX.” Put them together, and we get two almost identical but slightly
different sets of 23 chapters. The tiny variations are what makes
each person different. It’s estimated
that all the chapters together hold about 20,000 individual
instructions, called genes. Written out, all those 20,000 instructions are 30 million letters long! If someone were writing
one letter per second, it would take them almost
an entire year to write it once. It turns out that our genome book
is much, much longer than just those 30 million letters — almost 100 times longer! What are all those extra pages for? Well, each page of instructions
has a few pages of nonsense inserted that have to be taken out
before we end up with something useful. The parts we throw out, we call introns. The instructions we keep, we call exons. We can also have hundreds
of pages in between each gene. Some of these excess pages were inserted by nasty little infections
in our ancestors, but some of them are actually helpful. They protect the ends of each chapter
from being damaged, or some help our cells find
a particular thing they’re looking for, or give a cell a signal
to stop making something. All in all, for every page
of instructions, there’s almost 100 pages of filler. In the end, each of our books’ 46 chapters is between 48 and 250
million letters long. That’s 3.2 billion letters total! To type all that copy, you’d be at it for over 100 years, and the book would be
over 600,000 pages long. Every type of cell carries the same book, but each has a set of bookmarks that tell it exactly which pages
it needs to look up. So a bone cell reads only the set
of instructions it needs to become bone. Your brain cells, they read the set that tells them
how to become brain. If some cells suddenly decide
to start reading other instructions, they can actually change
from one type to another. So every little cell in your body
is holding on to an amazing book, full of the instructions for life. Your nose reads nose pages, your toes read toes pages. And that little thing
in the back of your throat? It’s got its own pages, too. They’re under “uvula.”


  1. it's all chemistry – see what you missed in chem class? if you want to learn how a organism is made look up embryology. If you want to learn how they all communicate with each other become doctor, possibly a neurologist. And no there's no higher intelligence guiding it, a doctor doesn't diagnose you by conferring with some higher being – just because it's complicated for you doesn't mean a higher being is involved, it just means you don't understand it.

  2. also it's not blind chance it was evolution through natural selection. through evolution complexity can arise iteratively over long period of times. From the simple can come complexity. One can not simply say this stuff seems so complex so an intelligence must have did it, because that infers the intelligence is even more complex, which means something even more complex must have created it, etc… into infinity. The more stable solution is from the simple comes complex.

  3. some "junk" does, he mentions the switches which were once considered useless, some "junk" is viral (he mentions these too), that is serves no purpose but to replicate itself from generation to generation and some "junk" is just left over useless code that degenerates over time. nature is a crappy coder basically and doesn't tidy up it's useless subroutines like a good engineer would (that's because nature has no brain it's just a process).

  4. who said higher being? i didnt.. i said intelligence. i said co-ordinated. I think its pretty silly that doctors and chemists think they understand this the human organism. In ten years we will look back and laugh at what is held now as common knowledge. This is how the evolution of thought has always been. I did say "highest intelligence". and what i meant by this was that the human central nervous system (which includes the brain) is the most dynamic and intricate system in the known universe.

  5. so i guess we need to define the word intelligence. For me intelligence is the organizational capacity of information in any given system. It seems the way we quantify intelligence in the human organism is how they organize and communicate data. SO the cells of the human body are REALLY good at this. so good that it communicates and transmits data continuously and holistically faster than we can track or really even grapple with. so cells are atoms.. atoms are 99.99% empty space. so what is it?

  6. Definition: " the ability to learn or understand or to deal with new or trying situations" I don't think one can impose their own definition on something that is already defined. To think that symbiosis is synonymous with intelligent is a completely misleading term because it implies another force other than physics is controlling physics >.>

  7. "the ability to learn or understand or to deal with new or trying situations". This is not so different than organizational capacity of information. Lets say you have a pathogen in your body, your cells need to communicate this to those cells which have the capacity to deal with the pathogen. So can physics describe how the body knows what a balanced hormone level is? how does it know when to code for what amino acids? what is the signal that says we need more pigment in the eye?

  8. ok i was a bit confused i guess, u seemed to infer there was a consciousness behind the coordination of cells, i took that to mean an intelligence, but other than that misunderstanding there is no intelligence that coordinates the cells it's all just chemistry. of course no doctor/scientist claims to understand it all but they do have understanding of several aspects of it. DNA is present in all living organisms even plants which have no nervous system and yet they still are constructed via dna.

  9. yes physics and chemistry can describe those. The immune system is amazing and basically exhibits evolution in realtime, that's how most pathogens get neutralized – look up Somatic hypermutation. For timing of coding look up Hox Genes and Embryology. Of course not everything is known but they are making headway in that field – they do know a lot more than one would expect.

  10. The fact that protein bind through various energy affinities demonstrates that physics govern everything. The fact that the way proteins are transcribed and translated though random diffusion of amino acid residues in the cell is a prospect of physics. Our bodies are vats of chemical reactions which govern the way we feel and interact with the environment. The is no intelligence to it, because the reactions of certain molecules are govern by the laws of physics!

  11. And to think…we were all created by two microscopic seeds of life!

    We are all miracles-works of art.
    Born the same, but none the same.

    Such exquisite precision of the survival struggle.

    We are what dreams are made of.
    And what they cannot live without.

    The mingling schism of fantasy and reality.
    Two best friends growing old together.

    The immortal-balancing act.

  12. *giga base-pairs if I'm not mistaken. How the data were to be stored on a computer could vary depending on the file's compression. I might be wrong though.

  13. Isn't having a set of instructions for every body part for every cell incredibly inefficient? Won't it make us more susceptible to genetic mutations and diseases?

  14. forgive me holy-rollers if i prefer to trust in the information of a billion year old "book" vastly more complex and informative than some 2000 year old man-made fairy tale

  15. Redundancy is a benefit actually. It means if one copy gets destroyed, there's still a copy in every other cell in the body!
    Besides, evolution isn't about efficiency. Look at all that junk DNA!

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  17. I still don't get how a cell knows which pages it has to read. If it is so that the cell gets "bookmarks" in it's DNA, that would mean that the DNA differs per type of cell, and that isn't the case. So what is it!? TO THE INTERNET!!! [Batman tune] 

  18. I don't totally agree with this video. There are no genes to form a nose or a uvula or limbs. They are formed as a consequence of the development process and the genes that regulate this are expressed at different times and intensity. This makes the whole difference. This is how a chicken doesn't have a dinosaur tail anymore or teeth. These genes are the same in all vertebrates, same signaling pathways with different consequences.

  19. is this dark magic? i need to learn more on how the hell can u fit an equivilent to 3 feet in 1 timy space smaller then an atom

  20. Whoaaaaaahhh. It's wonderful. Thank the author/ teacher.
    "in Your book all the days of my life were written before ever they took shape, when as yet there was non of them. How precious and weighty also are Your thought to me, O God! How vats is the sum of them. If I could count them, they would be more in number than the sand… For You did form my inward prat, You did knit me together in my mother's womb." (Ps. 139)

  21. but the real question is if all those cells have the same book same DNA same instructions shouldn't they do the same thing but we see some became brain cell some blood cells what is telling what cell to do what?

  22. 저는 이 동영상이 갠적으로 맘에 듭니다~유전자란 신비적이라서 가장 갖고 싶은 염색체져~~~~~~~~~~!!!!!!!!!!

  23. can someone tell me what would happen when one cell want to read and become an other cell in a group? (I mean if a cell in brain read and become a bone cell)

  24. I really good and well spoked video 🙂 Very informative and captivating, it hade 4 minuts feel like seconds! I like to see Joe Hanson on Ted-Ed aswell, always though he wuad qualify. Thanks for yet another amazing video 🙂

  25. thanks for putting the captions, you speak fast. hard to keep up when you're teaching us so much in such a short amount of time! thank you!!

  26. Wow…no doubt…it only proves that we are created by God and His intelligence is higher than ours…

    Psalm 139
    For you formed my inward parts; you knitted me together in my mother's womb. I praise you, for I am fearfully and wonderfully made. Wonderful are your works; my soul knows it very well. My frame was not hidden from you, when I was being made in secret, intricately woven in the depths of the earth. Your eyes saw my unformed substance; in your book were written, every one of them, the days that were formed for me, when as yet there was none of them.

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