welcome back to our video series on plant diversity and evolution in this video we're going to look at the reproduction in seed plants gymnosperms and angiosperms we're going to use the pine tree as our poster child for all gymnosperms and basically any flowering plant to represent the angiosperms remembering that in the gymnosperms or in the Pines at least the reproductive structures are cones and in the anges sperms they're flowers now I may turn this into a two-part video uh how long it takes me to get through the gymnosperms but uh let's start there so the life cycle of the gymnosperm looking at the pine trees we have the reproductive structures the cones but there's two types of cones there are the female cones or the seed cones sometimes are called The Woody cones they're what you think about when you kind of visualize a pine cone but we also have male cones or pollen cones they're smaller and spongier in texture and obviously they're the ones that going to make the pollen let's look at the male side of things first here's a pollen cone remembering that this is the sporify generation that we're seeing the Dio generation and spor fites make spores so let's zoom in on part of this pollen cone this spor fight is going to make spores and since the spor fight is diploid and the spores haid we need meosis now specifically since we're going to make the microspore remembering that seed plants are heterosporous we have a micro microspore and a megaspore and so in the pollen cone through meosis we make the microspore now we know that spores become gametophytes and the microspore specifically becomes the male gapy and if we remember in seed plants the male gapy is pause video write down what I'm about to say pollen that's right the male gamify in seed plants is pollen this represents the gamify generation at least on the male side let's move over to the female side and look at the Woody cones or the seed cones and if we zoom in on a section of this one of these scales and then we zoom into one of those we see an ovule and again this is the sporify generation so inside the ovial is a cell called the megaspore mother cell now if it's a Mother cell it means it's going to give birth to some other cell and it's the cell that's going to make the megaspore so it's diploid it's the spor fight generation we're going to need meosis to make it haid so inside the ovile the megaspore Mother cell undergoes meosis making four Hao cells now only one of these is going to become the megaspore these other three kind of go away they're not important now this megaspore is the HAPO Spore and we know that spores become gyes so it's going to grow by mitosis to become the female gapy so this and I've blown it up a little bigger here inside this female gamify are a number of cells one of which is the egg because gyes make gtes and the other is the endosperm Mother cell which is going to give rise to the endosperm now we're going to talk more about the endosperm but it is the nutritive tissue that's going to sustain the embryo after fertilization but we don't have it yet we just have the cell that's going to give rise to it so the poll cone made pollen and in the seed cone uh in the seed cone we've um set up everything to make a seed we just need pollination to occur so here we have our female gapy M holding our egg in our endosperm Mother cell and we just need pollen in the pine trees pollen is brought by the wind it's wind born it's not brought by a pollinator like we might see in flowers no no insects involved here so the wind blows pollen over here and when the pollen reaches the scale of the cone it uh discharges the sperm the sperm is going to fuse with the egg and fertilize the egg and make the zygote the endosperm Mother cell divides producing the endosperm now the zygote is diploid it's the result of fertilization the endosperm the nutritive tissue around the zygote is haid now the zygote will become the embryo and surrounded by the uh endosperm the nutritive tissue and we formed the seed now the seed uh if we go back to the seed cone the seeds are found here when the cones mature the scales peel back like you see in this picture and the seeds can fall out of the cone land on the ground and grow into a new pine tree and that's going to do it for the life cycle the gymnosperm now I'm going to make the angiosperm life cycle and reproduction its own video it takes a little longer so come back for that one if you have any questions about this one leave me comments below uh the video and um I hope you learn something