 Okay, so today we're going to be talking about mitosis. With mitosis, all of your somatic cells are capable of this. They all contain 46 chromosomes, which are organized into 23 pairs. 23 from the mom, 23 from the dad. So in order to understand mitosis, we're going to act it out for you. So get your study group and start walking. So what we're going to start off with today is two of our chromosomes. We've got one from the dad, one from the mom. These chromosomes are going to be loosely linked together, okay? And they're so loosely linked together that you can spread them out, move them around and manipulate them however you choose, okay? But all in all, when you look at the chromosomes, you've got one from the dad, one from the mom, and they match up and contain the same alleles, okay? So when we talk about mitosis, the first thing that we have to do is we have to replicate all of the DNA so that we can create two identical daughter cells. Obviously, if we were to split the cell right now, we would end up with one cell that has half the DNA, just one dad and one with just mom. And we don't want that to happen. We want to have the same number in our progeny cells. So the first thing we're going to have to do is interphase, which is going to be where the cell is going to replicate all of the DNA, okay? So you can see the first thing that happened is that the DNA replicated. I now have two chromosomes from the mom that are homologous and two from the dad, okay? Now, after we replicate everything, right, we also have to replicate the organelles that are in the cell because it does no good if all one cell gets all the mitochondria and the other cell does not and it can no longer make energy. So if we had one mitochondria in each cell, okay? In interphase, we're going to replicate it so that we create two, okay? Two becomes four and so on and so forth. So now we have equal numbers of everything and we're ready for division, okay? First step of division is going to be, I forgot, pro phase, cut that out, pro phase. Pro phase is going to be where the chromosomes are going to condense down. We package them so that way we can make sure that when we divide, everything goes in equal directions, okay? So we condense everything down. The nuclear envelope that was surrounding here is going to disappear, okay? Also during pro phase, our centrioles, which come in a pair, are going to divide up and one goes to one side of the cell. The other one goes to the other side, okay? These are going to be where our new nuclei are at the end of division, okay? After pro phase, we are now going to line up into metaphase. Metaphase is where all the chromosomes are going to line up at our mesophysical plate, okay? Metaphyseal plate, so here we go. One, two, now you can't see me anymore because I'm also in the middle. So everything has now lined up in the middle of the cell, okay? You can clearly see there's a pole on either side and that all of our chromosomes are aligned in the middle of the cell, okay? The next part is going to be anaphase. Anaphase is going to be where the centrioles send out spindle fibers and grab one of the each of the other chromosomes. Grab one mom, grab one dad and drag them back to their sides of the pole, okay? Now what we have is we have two separate organizations of chromosomes, right? One on one side, one on the other, okay? That separation is what we call anaphase. After anaphase, we now have to do the reverse of prophase. We have to close everything off and we have to form new cells. So in order to do that, there's going to be a cleavage furrow that's going to form in the center of the cell, okay? In the process of separating up, the cytoplasm is called cytokinesis, okay? So what we're going to do is we're going to reform the nuclei on either side. We're going to divvy up the organelles instead in half one way, half the other, okay? Group together. And what we've done, and you can see, is that we've created two separate cells. Both cells have a copy of the chromosomes from the dad, a copy of the chromosomes from the mom, and equal number of organelles. So we have completed mitosis and we're ready to start the cell cycle all over again. Thanks.