Pollination

by Jason Amores Sumpter
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up to this point. We've been talking about all flowers like they're the same. But as with everything in biology, there are exceptions, and there is variety and diversity, and that's a good thing. And we need to go over some of that terminology. So we've actually been talking about what you'd call complete flowers. That is, flowers that contain see pols, pedals, stamen and pistols all parts. Some flowers, though, are considered incomplete, and that's because they're missing. One of those components may be more than one of those components. In fact, now you can also have what's called a perfect flower, which is going to be a bisexual flower that has statement and pistol structures within the same flower. That's as opposed to what's called an imperfectly flower, which has either stamen or pistols and is Eunice Sexual Now amongst Eunice sexual flowers. We can get another dichotomy, and that is the difference between munitions plants and delicious plants. Now money cious plants and diocese plants both have, you know, sexual flowers. But in mani cious plants, the male and female flowers will be found on the same plant, so one plant will have some flowers that have male parts, some flowers that have female parts. But it's all in the same plant di cious plants. On the other hand, we'll have just male flowers or just female flowers on the same plant. So the male and female floral organs are separated by plant. In here. You can see we have some images to represent all this stuff. So here we are, looking at in complete flowers, and this one is male. This one is female. And here we have a, uh, a perfect flower. Actually, I'm sorry. This supposed to be in perfect? Not in complete. Well, actually, it could be incomplete. It's both incomplete and imperfecta, actually. So in perfect. Perfect. But over here is where I wanted to show are incomplete. Complete dichotomy. Get my head out of the way. So this is a complete flower. It's got the, uh You can see the stigmas up at the top. There. Here are the answers. You know, this is the style The ovary is gonna be down in there. You can't really see it. It's got pedals. You can't see it, but it has Cibeles under there. It's a complete flower. This is an incomplete flower Oh, if you're curious, this is a yeah. On the left. Here we have a hibiscus flower on the right is a calla lily, and while this might actually look like a pedal, it's not. It's a leaf. It's a leaf that has had its color altered to appear, a za pedal to fool pollinators, so to speak. And this structure is actually a covered in pistols, though you'd have Thio look through a zoomed in lens to really see it. But the point is, it's incomplete. No, if we move on, we need to talk about how pollen gets around, as I'm sure you may have thought. You know, if ah flower has the male parts and the female parts well, then can't it pollinate itself? The answer is, sometimes some plants can self pollinate, but others can't. Others will cross pollinate, which is when a when pollen is transferred from the anther of one plant to the stigma of a different plant, and some plants are prevented from self pollinating by genetic mechanisms. We call this self incompatibility so that it that is when genetic mechanisms prevent self pollination, and this encourages what's known as out crossing, which is when you breed genetically unrelated individuals. Now there are other methods that plants use to prevent self pollination. One of these is known as temporal separation. Essentially, the male and female comedic fights on a plant will mature at different times, so that neither one is mature at the same time, meaning it can't pollinate itself. However, other plants will have their male and female Gumede a fights match maturing at, um, you know, on a different schedule and so those guys can get together. There's also spatial avoidance, which is basically spatial positioning of male and female flowers or floral organs to avoid self pollination. So if pollen has to get to stigma, for example, maybe all your female flowers are somewhere with the male flowers can't get their pollen to them. Or, for example, you put your stigma and anther within the same flower in a confirmation where the anther can't hope to get its pollen up to the stigma, for example. Now, lastly, we need to talk about pollination syndrome, which are flower traits that have evolved in response to pollen vectors. So these are going to be traits that influence a plants ability to pollinate by wind or by attracting bees or by attracting birds for that matter. And the reason that you have organisms that will pollinate these plants is because of mutual is, um, right. They're not doing this for free. It's not a charity. There's something that they get out of it. The animal pollinators like this dusty, be covered in pollen here or this be slurping up its meal or this hummingbird behind my head here, slurping up its meal. They're getting food. They're not. They're thinking, All right, I'm gonna take some of this pollen bringing to this other plant later. See? No, they're like, I'm getting a meal right now. And you know, it's got to get a little dirty to get this food right to get dusty in the process. I don't really care. I'm getting a delicious, sugary snack, and when I go to my next meal, I might rub off some of that dust that pollen on that plant, right? So the plants get to spread their pollen around the pollinators, get a meal out of it, and what we see often with these pollination syndromes is co evolution, which is when, uh, one species evolution influences the other species evolution. So ah, lot of these pollinators and flowers have co evolved. In fact, when Darwin, the father of the idea of natural selection and all that good stuff when he went to the Galapagos and he saw this particular flower that had this really long tube down to the neck tary, he said, I bet you that there is some organism that has evolved to have a feeding tube that will fit into that flower. He was not wrong. He didn't discover that moth, but he was right in predicting that it existed. And that is just one eloquent example of co evolution. And you're going to see that with these pollinators and the organisms that their pollinating for because they rely on each other. Right, This is the food source for those animals. And this is how these angiosperms are going to spread their pollen around. No, I should make note that not all vectors are animal vectors. You know, there's other stuff like wind, but the the really cool examples of co evolution come out with those animal pollinators. All right, that's all I have for this lesson. I'll see you guys next time