 So in this video, I just want to go over some of the models we have available here in the Roam lab That you'll see so in this one we can see fertilization. So here's our sperm going into the egg here You've got a two-cell stage. You got a four-cell stage These two collectively are more eulose This would be the blasto cyst the trophoblast The blasto coal And you can see that bi-laminar germ disc there. The yellow would be the yolk sac And finally gas relation Moving over to a different Okay, we can see in this one you've got your primary follicles secondary follicle and Then the graphene follicle so looking at the sperm here. So again the head or acrosome The body and of course the tail This would show you your first mitotic division you can see that right there This would be finally the completion of myosis to and Fertilization so again some of the same stuff here is a blastocytes two-cell stage more eulose these guys Corion would be this stuff surrounding it here You can see again our bi-laminar germ disc there yolk sac and neon there Corion now has developed into villi Okay Still seeing our yolk sac and amnion here Moving over Okay now we can see that yolk sac has really developed and then as the embryo grows the yolk sac is going to be depleted So we can see it's much smaller and we get the early remnants of the placenta So as the yolk sac disappears placenta is going to grow And we get that early umbilical cord going into the placenta for nutrients