 Now we're going to start out with the exact same cells when we're looking at meiosis and mitosis I'm actually going to draw this out for you And that seems a little tedious because we're going to have to draw all these chromosomes over and over But I want you to remember what I've drawn here is essentially a cell a Diploid cell where the haploid number is two. I don't know if you remember that that We can describe the haploid number with by saying n a haploid cell is 1n a Diploid cell is 2n. So the haploid number is significant. Our haploid number is 23 so I'll tell you right now Even though it might feel a little overwhelming to draw four chromosomes in each one of these stages of meiosis and mitosis We could be drawing 23 of them and You don't have to so we'll just do two Just so we can visualize all the things that are happening in these processes and where they're really similar I threw my ptosis on the right side of this diagram and again It should be familiar the first thing I want to draw and have a feeling I'm going to run out of room here I want to acknowledge. I want to draw what is going to happen to that cell what that cell is going to look like If it goes through the s stage of interface My ptosis does it and guess what? So does my osis and I'm making my cells Sausage like in order to fit them on this screen So Percolate remind yourself. What do you think this the chromosomes in? My mitosis cell, what are they going to look like? After they go through the s phase Well, we know in s of interface. We've gotten the message to replicate Happens in meiosis and mitosis and the task is Replicate your DNA the cell says got you dog DNA polymerase. Let's roll and Pretty soon we have chromosomes that look like this You know That if you see chromosomes that look like this s has taken place This is remember sister chromatids Yes, and my sausage like cells are not quite fitting my chromosomes oops I don't like that. Oops. I like that one. I didn't like gotta make it big It's got to be big. Why? Because the big ones are homologues and if you look on our agenda We're gonna spend an entire section Next up talking about homologues because I would argue that everything weird that happens in meiosis That's different from mitosis takes place with the homologous chromosomes and They're all about generating genetic diversity Okay, so let's focus That's it. I'm not gonna do anything else you will go ahead and It's awesome practice to draw out all the stages of mitosis and I'm just going to tell you that the stages of mitosis are prophase Metaphase Anaphase and telophase awesome and at the end result We have two Daughter cells that are identical to my original cell and Look, I'm not convincing you that this is true. I'm not drawing out all those stages I'm just drawing the end result and saying hey it happened. Look. They're identical I'm not gonna draw out all the stages in meiosis either and if you again look at our list our to-do list We're gonna go through the significant stages that are different What I'm going to tell you is that mitosis my osis happens twice So we actually have I'm just gonna do it like this and I'm gonna say prophase metaphase anaphase and telophase one takes place and We end up with two cells and I bet if I draw out What happened in these two cells? you Would be able to fill in some of the details some of the processes some of the Miosis one events that take place Notice that Miosis happens twice Each one of those cells that results from meiosis one is haploid look at that we have one copy of each homologue in The daughter cells at the end of meiosis one, but what else do you notice? Shouldn't be hard to observe we have too much DNA We have two copies of chromosome big red chromosome Connected at the centromere that's not how we want our cells our daughter cells to look That's too much DNA. We don't want two copies of the identical Chromosome we don't want sisters. Oh Sisters sisters got a hug, but they got to say bye-bye So what's gonna happen? We got to have PMAT 2 meiosis 2 takes place and in fact each one of these guys goes through meiosis 2 and Let's see here. I know I can do it. I'm gonna just go ahead and draw all of these for you. What are they? Unique haploid gametes if you look at this guy We're gonna end up with Do you agree with this? one copy of the big red one and one copy of the little red one in each of my gametes and These gametes result in One big copy and one little copy. Okay differences Well shoot We have four Resulting daughter cells. We have four unique haploid daughter cells If you look at what happened in meiosis 1 our homolog split apart and the processes of meiosis will illustrate how that takes place meiosis 2 is almost identical to mitosis because look sisters split Not homologs sisters split I'm gonna show you this is our visual. This is like the big picture of what happens I am gonna show you like a Normal person whatever somebody fancy made this diagram We're gonna revisit this at the end But the things that I want you to notice is here. We go meiosis 1 happens and meiosis 2 happens I like the way that they depicted this because they show Meiosis 1 is the weird one. It's the one that isn't similar to mitosis mitosis is Really similar to meiosis 2 do you see how? Having a solid understanding of mitosis will help you with this whole process alright I'm gonna make a broad statement. It's a statement that I think I've already made Everything unique that happens in meiosis everything Different that happens in meiosis happens because of homologous chromosomes So we have to spend a little chunk talking about those clowns