Land Plants

by Jason Amores Sumpter
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Hello, everyone. Today we're going to be talking about the different types of land plants and how they evolved over time. Alright, so land plants originally evolved from algae that lived in the water, specifically green algae. Because there are different lineages of algae, there's brown algae and red algae in green algae land. Plans on Lee came from green algae, so they evolved from these aquatic organisms and they evolved to live on land, which means they had very specific adaptations toe live on land because their environments drastically changed. Now this change happened around, I believe, 850 million years ago is when plants began to colonize dry land, which is a really long time ago. And they came from these freshwater green algae and they're gonna have very specific adaptations because, as you can imagine, moving from an aquatic environment to a terrestrial environment has its issues. And some of the adaptations which you will all learn more about in later lessons, are going to be things like the cuticle, which is a waxy covering of the plants which helps them retain water because they're no longer living in the water there now, living in the air, they have the possibility of drying out. They also have things like seeds, vascular tissue. Some of them even have Paul in, which allows them to reproduce without water, which is very interesting. So there are many adaptations which we will learn more about in later lessons. But right now let's talk about the lineage and the evolution of these land plants. So land plant, as we normally call them, is a very informal name. It's just talking about all of the plants on land, but this is a very informal name, and it's actually very interesting. Land plants also encompasses some plants that went back to an aquatic ecosystem that air now aquatic again. They went from aquatic to terrestrial to aquatic through their evolutionary processes. So land plants. If you want to be more specific, you're going to call them embryo fights. Embryo fights are a specific type of organism that holds the embryo or the developing offspring inside, off the tissues of the parent. Don't don't worry, you will learn more about that specific quality and later lessons when we talk about plant reproduction. I was just telling you why they have this particular name Now there are three types of land plants, non vascular, seedless vascular and seed plants, and they did evolve in that particular order. Non vascular plants came first, then seedless vascular and then seed plants. The majority of the plants that you think of are going to be seed plants, and they're going to be the youngest and generally the most specialized plants that live on dry land. But first, let's talk about non vascular plants. These were going to be the first plants that actually colonized land, and they're gonna be very similar to the green fresh water algae that they evolved from. So these were the first land plants, and they lacked these particular structures, called Trey kids. Now Trey kids are going to be a type of plant cell and trey kids ourselves with very thick walls made of lignin. Lignin is like cellulose. It is a very important structural component of most plants, except for non vascular plants. You'll find that seedless vascular and seed plants have this ligament cell wall component to their anatomy, and this is going to be very important for structure. This is going to give them the ability to grow taller and larger but non vascular plants. The first land plants didn't have Trey kids. They didn't have lignin, so they were not able to grow to great size so they could not support large vertical growth. They couldn't grow really tall. Now you would be knowing this. Now. You're probably not surprised. Thio here that non vascular plants are going to be things like moss and liver warts, which sounds awful, but they're actually not as awful as they sound. So moss, liver warts. I also believe horn warts are non vascular plants, and these were going to be plants that are also called Braila fights, which will learn more about in their own lesson. There's a whole lesson on Bryan fights, but these are very short plants, very small plants, Mosses, kind of like little little Tufts of hair or grass on the ground. They don't get very tall, and the reason is is because they did not evolve. Trey kids, they're the first land plants. They didn't have this adaptation as of yet. Now these plants are a gammy to fight dominant life cycle. You will find that the other two types of plants seedless, vascular and seeded plants are not. Give me to fight dominant life cycle there. Spore fight, dominant life cycle. And this means because they're gay. Me to fight dominant life cycle that they are hap Lloyd Most of their life, they only have one set of chromosomes the majority of their life, their dominant part of their life. Now they do have some sort of internal water conducting tissue, but they don't have vascular tissue that the larger plants of land today actively have, so they don't have as specialized water and nutrient conducting tissues. So that's also why they're very small. Now let's go into the next type of plants. We have the seedless vascular plants thes. We're going to be the ones that evolved. Next, seedless vascular plants are a para file ethic group, which I'll explain more when we look at the file a genie down here in just a second. Basically, what that means is seedless vascular plants that term. That group name encompasses the ancestor of vascular plants, but it doesn't encompass all of the descendants of that ancestor because the other descendants of that ancestor are going to be seated plants, and obviously they're not seedless vascular plants. They're seated vascular plants. So but don't get too much into the specifics. I'll show you guys the biology in just a second. Okay, So what's new about these plants is that they have vascular tissue. That means that they have specialized water conducting and nutrient conducting tissue that acts a lot like our blood vessel system does. It is able to transport water and nutrients to the extremities of the plant. This allows the plants to get a lot bigger because they're able to move water and nutrients farther. So these are also going to be plants that have a spore fight, dominant life cycle. Remember that non vascular, organ modified, dominant life cycle. See, this vascular plants are spore fight dominant life cycle, meaning that most of their life they're going to be deployed. They're gonna have two sets of chromosomes in their cells. Also, they evolved lignin like we talked about earlier, and this allows them to have strong vascular networks, and it allows them to support more vertical growth. So these were going to be larger plants thes. They're gonna be things like ferns and horse tails are also seedless vascular plants, so they have vascular conducting tissue. They're able to grow taller because of their lignin, but they don't have seeds as of yet. So now let's move on to the seeded vascular plants. So we just call these seed plants. But these air most of the plants that you think of today, whenever you think of a plant and this is going to encompass the gym, No sperms and the angiosperms. Two different types of seeded plants. Jim, no sperms have naked seeds. These air gonna be things like Conifers. Basically, what this means is they don't have an active protection around their seeds, and they don't have any parental part around their seeds. So the opposite of that is gonna be angiosperms. Angiosperms are enclosed seeds, so you'll find the angiosperms will commonly hold their seeds inside. I'm sorry I'm in the way. You guys, they'll commonly hold their seeds inside of a nut or inside of a fruit so their seed is enclosed. While Jim no sperms have naked seeds. It's not enclosed, so angiosperms are going to be all types of flowering plants. That is what makes angiosperms Sony unique. They are flowering plants, and they have pollen. So all seeded plants are gonna have pollen as well. These gym no sperms have pollen and so do these angiosperms. So they have vascular tissue. They have lignin. They have Trey kids, they have seeds. Seeds is a very important adaptation because seeds protect the developing embryo and they allow that embryo to have a better chance of survival. Alright, so just you guys know remember the gym? No, sperms are generally Conifers, so things like pine trees. All right, so now let's go down And let's have a look at this biology that we have here. So this is a pretty big file, a genie, and let me scroll down so you guys can see the bottom. So if the bottom here, you all can see that we have thes green algae species and these green algae species are going to be the ancestors to land plants. Now land plants are going to be from here and above. So those are going to be our land plants which you guys can see. It's as embryo fighter. So these air, the embryo fights or the land plants and the first particular types of land plants to evolve are going to be those Braila fights. Those are the non vascular plants, so non vascular plants are the bride of fights and these air going to contain the horn words, the Mosses and the liver, warts. Very low profile, very small plants. Now, as we go up in the file a genetic tree, we're going to move on to things like ferns and horse tails. So these are going to be our seedless vascular plants that evolved from our non vascular seedless plants. These are gonna be things like the ferns and the horse tales that we talked about, remember, They're now able to grow taller. They have lignin and they they have vascular tissue. They're able to transport water and nutrients around their bodies, so they're able to get larger. And this includes all of the vascular plants here, which is the vascular seedless plants and the vascular seeded plants. And as we move further up the file a genie, we can move on to the seeded plants, which are going to be things like Jim, no sperms and angiosperms. So these are our flowering plants are Conifers, our site cads, argan coz, and those are going to be gin goes and psych odds are not as common as Conifers and flowering plants, so you might not know exactly what they look like. Definitely recommend looking them up if you would like to know. But these were going to be more specialized plants, more specialized toe living on land because they're going to have things like pollen. They're gonna have things like seeds and flowers there, specifically adapted to live and reproduce on land. And remember, guys, they also have this vascular tissue and this lignin so angiosperms and Jim knows firms are generally the largest plants on our planet because of their structural abilities. And angiosperms are going to be the most successful, I guess you could say, or the most prominent types of plants on our planet, because flowering plants have done so incredibly well because they interact with the environment greatly and the interact with animal and insect pollinators very well as well. Okay, everyone. Now let's go on and learn more about specific types of plants and these specific adaptations that land plants acquired