00:01
I'm going to look at the process of mitosis and meiosis and what happens when cells replicate.
00:06
So we're going to do this by starting with a cell, just a normal somatic cell, meaning that it is not a germ cell.
00:21
It will not be producing gametes, so it will not lead to an egg or sperm, just all the other cells in your body.
00:29
We're going to say that this somatic cell has 36 chromosomes in it.
00:37
Most of the time, our cells are in g1 phase of mitosis, but when they get signals, they start to get ready to duplicate, they will go through s phase, so making sure that everything is ready and the cell will be fine.
00:53
And then when it actually does go through g2 phase, it will duplicate its chromosomes.
01:08
So we'll start with 36 and you'll end up with two, you'll end up with a pair of everything.
01:13
So here there'll be 76 chromosomes in one cell, and that's sort of mitosis.
01:21
And then it will go through m phase or meiosis, and you'll end up with two daughter cells, each one having 36 chromosomes.
01:36
We can talk about meiosis real quick, this process of separating one cell into two.
01:49
So there are a few different phases to meiosis.
01:52
There is prophase, where you actually duplicate all of the chromosomes.
02:05
So if you start out with four and by prophase, you will have eight.
02:19
And then it will be metaphase, where all of these pairs of chromosomes now will line up in the middle of the cell, and there will be spindles attached to both sides.
02:37
So that way in anaphase, these pairs of chromosomes can be pulled apart.
02:48
So you have half on each side.
02:51
And then it will go through telophase, where the cell will start to cleave and you'll have organelles and these chromosomes pair off into the two different places before it finally goes through the process of cytokinesis, where you'll have two distinct cells.
03:21
So then we got the daughter cells finally.
03:23
And that is everything that's going on here.
03:29
And for a somatic cell, that's where everything stops...