Who else understood this a lot better than their 3 hour lecture?

My lecturer went over this for a whole hour and I didn’t get it, you spent 5 minutes and it was perfect! Thanks

SORTING OUT THE PARTS: PROPHASE As the first active phase of mitosis, prophase is when structures in the cell’s nucleus begin to disappear, including the nuclear membrane (or envelope), nucleoplasm, and nucleoli. The two centrosomes, duplicated in the synthesis process during interphase and each containing two centrioles, push apart to opposite ends of the nucleus, forming poles. The centrioles produce protein filaments that form mitotic spindles between the poles as well as asters (or astral rays) that radiate from the poles into the cytoplasm. At the same time, the chromatin threads (or chromonemata) shorten and coil, forming visible chromosomes. The chromosomes divide into chromatids that remain attached at an area called the centromere, which produces microtubules called kinetochore fibers. These interact with the mitotic spindles to assure that each daughter cell ultimately has a full set of chromosomes. The chromatids start to migrate toward the equatorial plane, an imaginary line between the poles. DIVIDING AT THE EQUATOR: METAPHASE After the chromosomes are lined up and attached along the cell’s newly formed equator, metaphase officially debuts. The nucleus itself is gone. The chromatids line up exactly along the centerline of the cell (or the equatorial plane), attaching to the mitotic spindles by the centromeres. The centromere also is attached by microtubules (spindles) to opposite poles in the cell. PACKING UP TO MOVE OUT: ANAPHASE In anaphase, the centromeres split, separating the duplicate chromatids and forming two chromosomes. The spindles attached to the divided centromeres shorten, pulling the chromosomes toward the opposite poles. The cell begins to elongate. In late anaphase, as the chromosomes approach the poles, a slight furrow develops in the cytoplasm, showing where cytokinesis will eventually take place. PINCHING OFF: TELOPHASE Telophase occurs as the chromosomes reach the poles and the cell nears the end of division. The spindles and asters of early mitosis disappear, and each newly forming cell begins to synthesize its own structure. New nuclear membranes enclose the separated chromosomes. The coiled chromosomes unwind, becoming chromonemata once again. There’s a more pronounced pinching, or furrowing, of the cytoplasm into two separate bodies, but there continues to be only one cell. SPLITTING UP: CYTOKINESIS Cytokinesis means it’s time for the big breakup. The furrow, formed by a contractile ring that will divide the newly formed sister nuclei, migrates inward until it cleaves the single, altered cell into two new cells. Each new cell is smaller and contains less cytoplasm than the mother cell, but the daughter cells are genetically identical to each other and to the original mother cell, and will grow to normal size during interphase.

I'm trying SOOOO hard to understand everything in Campbell's Biology book but after the first few sections of a chapter I just can't focus anymore, it all just goes WA WA WA WA WAAAAAH, WA WA WAAA WA....this helps tremendously thank you Khan academy!!!

LOOK OUT HARVARD I'M COMING FOR

The way you explained this was pure love!

Perfect introductory explanation! I'm continuing zoology after a two years of break. Thank you Khan academy

you already know I have a test in pre-ap bio in 5 minutes so im cramming super quick

5 feet and 2m have a huge difference

wow, great video!!! So clear and straightforward! Congrats!

Love the comparison to seasons and the pictures. Thank you

Humans aren't about 2M. 2M is about 6.5 feet.

Perfect explanation ......better than a 3 hours lecture !!

I admired ur way of explanation..have a blessed life sir

Thank u sooo sooo much Sir This literally helped so much :)

This video made things clearer thank you!

Thanks for the lecture. It helped a lot👍🏾

I don't think an average person is 2m tall .... or maybe I'm too short :(

very very well explained... thanks so much

Thank you so much for this video I needed this ❤️❤️

thank you khan academy for this information. ,

Thank you. Gid bless this institution.

thank you sooo sound and understandable!

THANK YOU!!!! This video helped me a lot on my TEST (

I like this guy's voice, he sounds dedicated and very clear lecture

Very helpful! Thanks

excellent explanation thank you!

Very short and simple... Thanks... Have a test on it tomorrow 😌

Great work, mister!

Thanks a lot !

Good explanation for an AP Bio student

simple illustration. Good job

thank you for the good video!

So underrated deserves more views subs and likes 😦

This is great

Thanx a lot brothr!

simply uh-mazing!!! fricking easy to understand :)

well done khan I understood it from you more than our professor

Excellent breakdown.

So helpful

Thanks so much !!!!!!

Thanks!

You should keep it up (:

I enjoyed your video on interphase. I look forward to watching your videos on mitosis.

Perfect ❤

thank you khan academy

😀thanks

i love how i can understand this 5 min more than a 1 hour lesson

Nice video!!!!

amazing.

I can finally ACE my FINALS! Thank you so much!

im from egypt and i thank you for your explain is very good

awesome

U r a legend😘

Great

best explanation video for non science background people despite the fact its a really difficult concept

Thx

I am here for two reasons, really. I need to prep for a cell division and inheritance test. Additionally, I need more science for my Fiction stories.

Nice 🙂

NICE

Why does he lowkey sound like the actual Khan? the repeating of a word while struggling to find a new color lol ..we found the IMPOSTER!!!

I love your hand writing, literally the biggest reason why I stayed to watch the video and subscribed lol

thx sir

Super

Ugh the teacher torched me and put this on the quiz i didn't study for this nor I had the materials wow..............

This sounds so simple yet my textbook and my teacher makes it seem so complicated

thank you!

most cells go through the Go phase. Some cells stay there permanently and others continue to the S phase but it's part of the cycle for all cells.

Thanks for this I have a test fore this in 10/23/2019

How do you know when a cell dose to the GNot Phase?

love the video and explination..how long is the process...does this happen in seconds..minutes..hours..days...weeks ect. ? @khanacademymedicine

During the S phase, It's the number of chromatids that double not chromosomes.

during mitosis, what is interphase doing?

🙏🙏✨

Hi I am surian you mast proffesor

Tell me a better lecturer than this narrator.🙌🏽 Thanks bro.

👍 👌 video but i have one question if the neurons stop dividing when they mature why are there older patients with brain tumors?

Thank you :) I think there is a small mistake, the cell has 46 chromosomes in the nucleus, they come in 23 pairs and not 46 pairs !

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❤️❤️😍

How about Cytokinesis? The cytoplasm division? Isn't it included in the cell cycle?

Why can the cell in G0 back to G2? And what is the different inside the cell that in G0 and G1?

since a cell's diameter measures 100 micrometers and a micrometer is 10^-6 of a meter... at 1:40 shouldn't it be 1/10 000 of the human size?

how does the cell know that it needs to go into the next phase? why does the cycle not move backwards? how does the cell know?

neurons do divide! Remember that.

Sir. As FROM THIS DEFINITION ;THE INTERPHASE IS THE INTERVAL BETWEEN TWO SUCCESSIVE DIVISIONS .🤔🤔🤔🤔🤔 Sir what are the names of these two successive divisions please let me know I am very confused

Does the S phase only happen to sex cells (gametes) or all cells experience it? The video explains "many" cells go in that direction but I thought it's only about sex cells. (Thanks superb clear explanation video!)

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Wait why In my book that making protein in (s period )not (g period )?! Now I’m confused

Harvard bouta not know what hit them 👊🏼

biology 2?

👍

Can anyone point me towards some independent cancer research publications? I've only found official publications from institutes of higher learning but I've never seen anyone actually independently work on this subject enough to correctly explain the science behind their research.

Khan academy is so wordy.

How is inter and G1 both phases a place were cells spend most of the time?

What phase of chromatin can I see 30 nm fiber in the cell cycle?

Doesnt M-Phase consist of mitosis and cytokinesis? not just mitosis?

Why am i not getting it

G0 cells are a vibee

Dude, 5 feet = 2 meters hahaha For reference, 2 meters are about 6 ft 6 or 6 ft 7. I got a heart attack when you said the average person is 2 meters tall :D