 Let's talk about aneuploidy. Aneuploidy is a condition that happens when essentially meiosis messes up. And if meiosis messes up, it's called nondisjunction, and nondisjunction happens during anaphase when chromosomes are being pulled apart. So whether homologs are being pulled apart or sister chromatids are being pulled apart or if they don't get pulled apart properly, then you're going to end up with a wonky number of chromosomes in your gametes. You could end up with an entire chromosome that's missing from a gamete. You could end up with two chromosomes instead of one chromosome in a gamete. And sometimes, aneuploidy result, it's a deal breaker, done. Game over, you die. You probably don't even know you're pregnant in some cases because the miscarriage will happen so fast that it's just you can't function with aneuploidy in some cases. But there are other cases where aneuploidy is okay. And take a look at this karyotype right here and tell me if you can find. This is not a normal karyotype. Tell me if you can find the condition. Go ahead and push pause and see if you can find it. The way you're going to diagnose this is you're going to look through and see if you would expect two chromosomes in every category. So far, so good. We've got two chromosomes of every type so far. There we go, until we get here. Chromosome number 21, we actually have three of them. So clearly at some stage in anaphase, two chromosomes were not separated. And we ended up with three of three of chromosome 21. Chromosome 22 is normal. Chromosome, the sex chromosomes, what do you see here? I see two ex chromosomes. So this is a female child with trisomy 21 or Down syndrome. This is an example of using a karyotype to diagnose the situation. What about this one? Do you see anything going on here? You can go through and look at all of your chromosomes. Fantastic, looks really good. We've got two exes, that's great. It's a girl child, nothing's wrong, except we also have a Y. The presence of a Y chromosome means you're a boy. Like that Y chromosome will make you a boy, but the two exes are going to cause some interesting stuff. X, X, Y, it's client filters, you're a sterile male and you may have some female body characteristics and in some cases increased learning adventures. So essentially you may have some mental issues. You will be a boy because of the presence of that Y chromosome. Let's look at another one. Look here, this one, everything else looks fine. It looks like we only have one ex chromosome, no Y, and no other ex. This is called Turner's syndrome and this is a female because we are lacking that Y chromosome, but this person is usually, doesn't undergo puberty. That's interesting. Let's see if there are some other ones. Here's the trisomy X. This is apparently not much happens with that one. That's interesting. So essentially the whole point is that if we have an issue of non-disjunction where the chromosomes don't properly separate, we can end up with an abnormal number of chromosomes that will have phenotypic consequences or most likely have phenotypic consequences. Not all aneuplates are bad and certainly not all are survivable. Some of them are game over. All right, we're going to look at more examples of aneuplates. I thought I already looked at examples of aneuplates. I'm skipping the examples of aneuplates because I think I just did that part and now we're going to talk about pedigrees.