00:01
We are going to be looking at the process of meiosis and breaking out the differences between meiosis 1 and meiosis 2.
00:06
So if you look over here on the left side, you'll see i have a little depiction of what it's like for a cell to go through meiosis 1 and then meiosis 2.
00:16
And so you start with a diploid cell that has both sets of chromosomes in it.
00:30
And initially, the dna will be loose.
00:34
It'll be just a chromosome on its own.
00:37
But after that cell goes through dna replication, and so by the time we get to meiosis 1, you will have paired chromosomes.
00:50
You will have a tetrad.
00:53
And so then you'll go through meiosis 1, and you have that tetrad, but by the time that you have meiosis 2, you will be back down to single chromosomes.
01:03
And i will show you why that is.
01:07
But when we have these single chromosomes and we have only half of them, here we will have gametes.
01:17
And that's the major difference between meiosis 1 and meiosis 2.
01:21
Meiosis 1, we just get cells, just normal cells from it.
01:28
But if a cell goes through meiosis 2, then it produces a haploid cell that we will, will call gametes, meaning haploid, meaning they have half of the amount of chromosomes that most cells do.
01:49
All right, so we are going to go through this.
01:53
In meiosis one, we start with a cell that has all of its chromosomes, and we will say that this particular organism has four different chromosomes.
02:10
So it has them and it's set in the pairs of chromosomes...