absolutely perfect. this really helped me with my biology test (95%)

@johnny_phouc_21

3 жыл бұрын

Why not 100%? Very poor effort, just not good enough...

@moelester3434

3 жыл бұрын

@@johnny_phouc_21 sorry man I’ll do better next time

@bub3124

2 жыл бұрын

@@johnny_phouc_21 lmao

@iamyou7631

Жыл бұрын

​@@johnny_phouc_21 Asian Parents be like:

@AbdullahGoraya-fk2kg

4 ай бұрын

u a doctor yet?

This is one of the best videos I've seen on Khan Academy to date. Extremely well done!

all the khan videos are so well explained , great work!

Nice analogy! Thanks so much, this really helped me!

This guy deserves a raise!!! Thanks for the video!

Thank you so much .. Beautifully explained .

super helpful!

I just want to take a moment to appreciate the artistry in this video! Well-explained too, thank you.

i love this but couldn't help but thinking awww when you said they decide what they want to be when they grow up and can be peer pressured

This is great Thanks!

This is awesome. Thank you!

thank you very much, i really love khanacademy and khanacademymedicine your video helps me a lot in understanding it and since my native language is not english, watching it while reading the subtitle really make it easier for me to fully understand the video

Thank you so much im gonna use this for my test tommorow

awesome video. also you sound exactly like mark ruffalo

do the proteins remain inside a cell to give a cell it's different look or do they get associated with cell like in the intercellular space ? Please answer

Thanks for the video. The art is really good and it really helped me understand cellular specialization

great! :D

Super interesting, I wonder if humans could differentiate in their professions more efficiently in a similar way

Will be using this in my test in three hours

Brilliant vid. Thanks for posting! :D

ty

perfect!

GOOD

Your analogy is even stronger... RBC do have a nucleus when made in the bone marrow, but they lose the nucleus (by some unknown mechanism) when mature.

@Hegeleze

6 жыл бұрын

Also, the 2012 Nobel Prize was awarded to some people who showed that mature cells CAN become pluripotent. They are called induced pluripotent stem cells.

But how are the transcription factors in the zygote formed or where are they from? And are they different from one another? In induction, is there a transfer of transcription factors from one cell to a stem cell?

@TonyTigerTonyTiger

7 жыл бұрын

A transcription factor is a protein, and is formed like other proteins .. via transcription of DNA into mRNA, and then translation of the mRNA into a polypeptide/protein. Just as there are many different enzymes, there are also are many different transcription factors, which allows them to turn on and turn off different genes. They can also act in pairs or triplets, etc. For example, in order for a certain gene to be expressed, it might needs 2 different transcriptions to bind to its enhancers. There are morphogens which can be released from one cell and effect other cells. The morphogens only trigger a signal cascade in the other cell, which can result in transcription factors in the recipient cell being produced. I personally cannot remember cases of trancription factors being released from one cell and taken in by another, but it has been 10 years since I earned my BS in biology, so don't trust me on that one thing.

@xoxomangakcorxoxo

6 жыл бұрын

BETA β nice question!

@abdullahraja1711

3 жыл бұрын

@@TonyTigerTonyTiger sir if zygote have all cytoplasmic determinants then zygote must express all his genes but this does not happens..... Why? 😶

@TonyTigerTonyTiger

3 жыл бұрын

@@abdullahraja1711 The zygote doesn't have all transcription factors that the embryo/fetus ever will have. It is a sequence of events: transcription factor "X" may not be made until 4 weeks after conception, and in only one specific small group of cells. As an analogy, you can think of an atomic bomb. All that is needed to get everything started is for one single nucleus to fission. When it does, it releases neutrons that are absorbed by other nuclei, causing them to fission. Each of those fissioning nuclei release their own neutrons, which are absorbed by other nuclei, causing them to fission too. At least theoretically, an egg could have only a single transcription factor that is distributed in the cytoplasm asymmetrically, and that would be enough to trigger everything from there. When the the egg divides, one daughter cell would have a high concentration of the transcription factor and the other daughter cell would have a low concentration. That could cause one daughter cell to express a transcription factor that the other daughter cell does not, and now you have 2 distinct sets of genes being expressed in the two cells. That's all that is needed to get 2 cells that have different genes expressed.

5.28 what happens to those cells that lack transcription factor , do they differentiate?

What level is this in the UK? GCSE? A-Level? Bsc?

What will happen to the cells which receive no transcription factors through mitosis? Will they be induced to differentiate via the states external options?

@Jonathan-rf5cp

4 жыл бұрын

The diagram is an oversimplification - in reality, there's hundreds of different transcription factors or mRNAs at the single-celled stage and the gradient from all of those combines to specify cell fate.

@abdullahraja1711

3 жыл бұрын

Sir if zygote have all transcription factors then zygote must express all his genes but this does not happens.... Why 😶

I had a little hard time understanding the internal cues... Someone who can give a simple explanation so i can confirm if i have understood it properly or not :D

@musharaf6269

3 жыл бұрын

Same here

Sir if zygote have all transcription factors then zygote must express all his genes but this does not happens.... Why 😶

@yeasminmarium5611

2 жыл бұрын

It doesn't happen because of the gene regulation.

This is soo general even tho this channel claims to be for medicine this video hardly covers 5% of this topic

Definitely evolution (haha).

Nice video. However, not only this still does not explain how stem cells GET stimulated to "READ" (use) the "BOOKS" (specific genes) of the "LIBRARY" (genome) for understanding how to make proteins, but it also does not explain how reading such genes could supposedly make the cells do anything!! Other thing this video does not explain is how proteins work to be the driving mechanism behind all of the cell's functions!! I think no mainstream science can explain these unexplained facts without resorting to hypothesis.

@TonyTigerTonyTiger

7 жыл бұрын

Your ignorance, and not science, is the problem.

@MrGodofcar

7 жыл бұрын

Your commentary is a problem, too, because it not only does not answer my indirect questions in my original comment, but it's also useless.

@MrGodofcar

7 жыл бұрын

Since you are saying that science is not the problem, I think you are implying that you scientifically know the answer for how stem cells get stimulated to read the genes, how reading such genes would make the cell do anything, and how proteins work to be the driving mechanism behind all of the cell's functions. If so, then do it.

@s4trat844

6 жыл бұрын

MrGodofcar look at 4:30 in the video this basically explains it

Nice. But I don't think that human eggs have an asymmetrical distribution of mRNAs and/or transcription factors.

@Jonathan-rf5cp

4 жыл бұрын

Most species, including mammals, use a combination of autonomous and conditional specification. Mammals lean more towards conditional specification, but autonomous specification still plays a role in early embryogenesis.

Is it me or does he sound a bit like Mark Ruffalo

he kinda sounds like Bill Gates ^^

Sorry sir, I speak engish

@GM.Nobody

6 жыл бұрын

Carter Bryson ???

@whatabash8888

5 жыл бұрын

😂

Clear and concise, but your voice is bloody sedating..