Seed Plants - 4

by Jason Amores Sumpter
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Hello, everyone. In our last lesson, we talked about the anatomical structures of flowers. Now we're going to talk about the different types of flowers that you confined on different types of angiosperms. Okay, so we previously talked about things like Cibeles pedals and thirst, filaments and things like that, right? The structures did you find within a flower? But those structures can vary depending on which type of flower you have. So there are complete flowers in complete flowers. Perfect flowers. Manu wishes flowers and die Alicia's flowers. So what we learned about previously what we saw previously were complete flowers. They contain Cipel's pedals, stamen and pistols. So see pols and pedals and remember that stamen includes the anther and the filament. And these were going to be the male structures that create pollen and create sperm. And then pistols include the stigma, style and ovaries, which are going to be the female components of the flower, which create the egg and will eventually create the seed or the fruit. Now, if it is missing, if the flowers missing any of those four structures, it is considered an incomplete flower. If it's missing any of those structures otherwise, it is a complete flower. Some examples of complete flowers are gonna be hibiscus flowers. Roses are complete flowers. P plants have complete flowers, and I believe two lips are also complete flowers as well. There's many more examples, but those were just a couple. OK, so now let's talk about the perfect flower. You may think that the perfect flower in the complete flower probably the same thing. That's actually not true. They have kind of confusing names. You would think a complete flower would be a perfect flower, but in fact it's not a perfect flower is going to be a flower that is bisexual. What that means is that it has male and female structures in the same flower, so that means it has a stamen and pistols. So this is stamen plus pistol. Now you may be thinking, Oh, well, then it's probably a complete flower. No, because it doesn't have to have seat bowls, and it doesn't have to have pedals, and it could still be qualified as a perfect flower, long as it's got a statement and a pistol so perfect flowers can be complete flowers, but complete flowers or not always perfect flowers so Manu Wishes and Dia wishes are gonna be two other types of flowers. So mono, Aetius and Die Alicia's. You've heard those terms used before. Generally, when you're talking about animals and the sexes of animals, so mono Aetius plants or mono Aetius angiosperms are going to have unis sexual flowers. That means that means that the entire flower is either male or female, either on Lee has answers or on Lee has pistols, but the's male and female flowers are found on the same plant. So what that's going to look like is if we have a mono Aetius species of angiosperms, what we're going to have is, let's say we have these two. Bush is here and there, the same species of angiosperms. We're going to have male flowers, and we're going to have female flowers in red, so male flowers and blue female flowers in red. So if we have these two individuals of the same species, they're going to have male and female flowers on the same plant. So both of these plants will have blue and red flowers. They will have both sexes of flowers on the same plant. This is Manu Aetius and generally, when we talk about Manu wishes organisms. We're talking about hermaphroditic organisms, organisms that possess both qualities of both sexes. And these angiosperms do fit that category. Now Die Alicia's Flowers or Die. Alicia's angiosperms also have unis sexual flowers, meaning that they have male Onley flowers and female Onley flowers. However, these air found on completely different plants. So what is that going to look like? Di Alicia's is going to look different because now, if we have the same two plants, but this species is delicious, we're going to have one male plant and one female plant. So let's say that this is the female plant with the red flowers and then one male plant with the male flowers that is a Daio Isha species of angiosperms. And that's because Daio Aetius is generally referring to to different sexes. Human beings air die Alicia's. There are individuals that air solely male, and there are individuals that air solely female. The same thing is happening with these particular plants. They have male flowers that are on Lee found on the male plant and female flowers that are only found on the female plant. These air die Alicia species so there are different types of flowers on different types of angiosperms. So some examples of mono Aetius plants would be things like squash and corn have both male and female flowers on the same plant. Some examples of Daio Aetius plants or die Alicia's angiosperms would be things like willow trees. If you've ever seen a weeping willow, it's dyou, Aetius, Holly uh, sassafras. And also poison ivy is an example of a die Alicia species. There's male and female plants. There are many other plants. Those were just some examples of the two different categories. Okay, so now since we talked about flowers, let's talk about the different forms of pollination that you can have dealing with those flowers. So first we're going to talk about cross pollination. Cross pollination is where pollen is transferred from one plant in the species to a completely different plant in the species. So basically one individual is fertilizing a different individual. Now this is going to be what is preferred in the reproduction off angio sperm plants, and that is going to be because this allows for genetic diversity. It is sexual reproduction. This is how to separate. Individuals are going to mix their genetics to create a zygote and eventually a seed or a fruit, which will create the new plant. Now this is in contrast to self pollination. If an organism or an angio sperm self pollinates, it is able to take pollen from its own anther and fertilized its own egg in the ovary. So that is self pollination. This is not particularly preferred because this is basically cloning yourself. You're basically not making any new, Um, you're not making any new genetic diversity here. Cross pollination is preferred, but some plants also can perform self pollination, if maybe if they need to reproduce. But cross pollination makes genetic diversity, and that is what they're looking for. Okay, so now let's talk about double fertilization. In fact, angiosperms do this really unique process called double fertilization. Usually, when you think about fertilization, you think of the sperm fertilizing egg to create as I go. That's single fertilization, and that's how a lot of reproduction happens. Angiosperms, however, do double fertilization. This is where a sperm fertilizes the egg to create a zygote, and another sperm is utilized to fertilize what's called the polar nuclei, which you're gonna become the Indo sperm. So let's go down and let's look at a diagram of this. So this here is going to be a diagram of the overall angio sperm life cycle. I'm going to go out of the picture so you guys can see the rest of this. So let's start on this side here. We see that the answer is creating the sperm and is creating the pollen grain. You can see the pollen grain right here, and the pollen grain is then going to be, um, used for the process of pollination, either by wind or by pollinators like birds, bees and butterflies. And the pollen is then going to be transferred to the top off the stigma on the, um on the female aspect of the plant. So then the pollen grain attach is to the female aspect of the plant, and it begins to create this pollen tube, and the pollen tube travels down into the ovary to fertilize an egg. Once it has reached an egg, then the sperm, which you can see right here thes air the sperm, the sperm are going to travel down the tube and they are going to fertilize the egg and they're also going to fertilize the polar nuclei. You can see that process happening right here. The egg is going to be fertilized. That's the first round of fertilization. And the second round of fertilization is where the polar nuclei cells are going to be fertilized. Now what's the point off the polar nuclear nuclei sells? Those are going to create the Indo sperm and you can see the Indo sperm right here. So we have the embryo and the Indo sperm. The results of the two fertilizations. The embryo obviously will become the new baby plant, and the Indo sperm is going to be the nutritional substance inside of the seed that is going to allow the baby plant to grow. You can kind of think of it like the yoke of an egg. It is there for nutritional purposes and it is going to give the embryo fats and oils and anything that it needs to continue to grow and to get out of the shell of that seed to create a seedling. So the Indo sperm is going to be the nutrition, and this is going to be the process of double fertilization, one fertilization is used to create the embryo and the other fertilization is utilized to create the Indo sperm, the nutrition for the embryo. And this is going to be a characteristic that is very unique to angiosperms. Okay, everyone, let's go on to our next topic.