Wednesday, August 8, 2012

Pollination (Bonus Post)


Like I said before, there are boy flowers, and there are girl flowers. (shown in the pictures below)


Male Plant


Female Plant

Now, here is a plant that is both BOY AND GIRL:

Male and Female Plant

Pretty nice, isn’t it? As you may have noticed, they have both the male and female parts. This kind of flower is rather special. Why? Well, if you read my last post on pollination, you will know that you usually need two flowers to make a seed. Well, with these kinds of flowers, you need just ONE flower to make a seed. Let’s look at how it does it.

On the previous post, I talked about pollen grains and ovules, which are the two halves of a seed. We also talk about the anther and the ovary, which makes the pollen and ovules. Usually, one plant has the pollen, and the other plant has the ovules. So, they need two plants to make a seed. They need to help each other.

But this special plant has an anther AND an ovary. This means that it can make both pollen AND ovules. It already has two halves of the seed together. That means that it can make seeds on its own. THESE KINDS OF PLANTS CAN MAKE SEEDS ON THEIR OWN.

Imagine this kind of plant as a really tough, lonely person. It dosen’t need help from other plants. It can survive on its own. It can make seeds on its own. It’s a loner in a lonely world. It is forever alone.

This is how it does it:


This kind of pollination is called self-pollination. This is because it can be pollinated by itself. Try to remember this, because this it is very important.  The seeds created only have one parent. If you read my previous post, you might be wondering whether this is considered wind or insect pollinated. Well, it is neither. You don’t need wind or insects. These kinds of plants are really special.  Only a few plants can do this, like peanuts and soybeans, because only those kind of plants have flowers that are both boy and girl.

There is also another way, and I explained it in the last post. Basically, you need two flowers, one must be a boy, and one must be a girl.  These plants are the opposite of the lonely plants. These are the lovey-dovey plants. Pretend this is a love story. The boy plant is Tommy. The girl plant is Mary. Tommy wants to make a seed with Mary, so he sends some pollen to Mary. So he lets the pollen fly away in the wind or get carried by an insect. Sadly, not all the pollen will reach Mary. However, a few lucky ones DO reach Mary. The pollen grains that do will land on Mary’s stigma. Then, Mary’s stigma will squirt out a sugary liquid. This sugary liquid tells the pollen grains to grow pollen tubes down into the ovules. So after the pollen tubes are connected to the ovules, the pollen grains pump in some cells that can pollinate Mary’s ovules. Mary’s ovules become pollinated, and they become seeds.Repro

This kind of pollination is called cross-pollination. This is important to remember. In cross-pollination, there MUST be TWO flowers. If you need to remember this, try to remember need two lines to make a cross, and these two lines are actually plants. There are two types of cross-pollination, one using wind and one using insects. (but that’s not really important for now.) Also, it is important to remember that the two flowers CAN come from different kinds of plants. For example, the boy flower could be from a durian tree, and the girl flower could be from an apple tree.

Both self-pollination and cross-pollination.have their good points and their bad points. Basically, with self-pollination, the seeds that are created will ALWAYS be the same as their parent. (There’s only one parent, remember that.) Why? Well, let’s think about yourself. Has anyone ever said that you look like one of your parents? Or maybe you act a lot like one of your parents. What I am trying to say is that you look and act like your parents. It is the same with plants. When the seeds finally grow up into adult plants, they will look and act like their parents (or parent, if there is only one).

Now, what would happen if you only have ONE parent. For example, you only have your mother. Well, when you grow up, you will look a lot like your mother, and you’ll probably act a lot like her as well. (If you want to know why, we will talk about it in a later post.) This is the same with plants. When a plant has self-pollination, the seeds that are created only have ONE parent. So when the seeds grow up, they will look a lot like the parent plant, and act a lot like it too. If the parent plant was a durian plant, the baby plant will definitely be a durian tree.

But why do you not look and act exactly like one of your parents? Well, that is because you have two parents. Your mother and your father both have different looks and behavior. So a part of your goes inside you, and a part of your mother goes inside you. Sometimes, your father’s part might be bigger, or your mother’s, which is why you sometimes look more like one parent than the other. However, you always have a bit of your father and mother inside you. (Sometimes a bit of your grandparents too, but that’s for another post)

Again, it is the same with plants. When two plants have cross-pollination, they have TWO parents, and the seeds that are created have a bit of their mother and father inside. This is where it gets interesting. If the two plants are very different, for example, the mother is an apple tree, and the father is a durian tree, then their baby can be very strange. The baby is a bit of an apple tree, and also a bit of a durian tree. Apples are small and sweet, and durians are big and spiky. So their baby might make a new kind of fruit, maybe one that is big and sweet. From now on, let us call these new kind of fruits, appledurians.

By the way I am explaining it, it might seem a bit easy to make new kinds of plants and fruits. Actually it is not. Some kinds of plants cannot accept pollen grains from other kinds of plants. They actually have a special way to reject pollen grains that they do not want, which I will explain later in the next section.

So, basically, with self-pollination, you get seeds that are a lot like the parent. With cross-pollination, you get seeds that are a bit like the parents but still quite different.

All right, ladies and gentlemen, without further ado, we will move on to the moment you have all been waiting for. Which is better, self-pollination or cross-pollination?


Good: With Self-Pollination, it is easier to make seeds, since you only need 1 plant. Bad: With Cross-Pollination, it is more difficult to make seeds, because you need 2 plants, and the pollen needs to be carried by wind or insect. Sometimes, the wind or insect might carry the pollen somewhere else, instead of the girl plant.
Good: If the parent plant is growing in a good place, its seeds will also grow near it, and they will also grow well because the parent plant and the child plant are a lot alike. Bad: With cross-pollination, there is a chance that the child plant will not grow well because the child plant is different from the parent plant.


Bad: If there is a disease that is killing the parent plant, the baby will probably die because it is a lot like the parent plant. Good: If there is a disease that is killing the parent plant, the baby might survive because it is different from the parent plant.
Bad: The babies of this kind of plant will be the same. And the babies of the babies will be the same. And so on. This might not seem so bad, but think about what would happen if every generation of humans are the same. We would still be cavemen, using stones to make fire and killing animals for food. Same thing with plants. There might be other plants that have super powers, but this plant will always be the same. Good:  The babies will be different from the parent plant. This can sometimes be good or bad. If for example, the parents are an apple and durian tree. Apples are small and juicy and Durians are big and spiky. So, the baby might turn into a small, spiky appledurian fruit which no one likes, which is not good. However, it might also turn into a big, sweet appledurian fruit, which is good. If it continues over a few generations, it might become an evolution.

So, both self-pollination and cross-pollination have their good and bad points. However, most plants like being cross-pollinated. Why? Well, most plants prefer having different kinds of babies, so that they can go through evolution. You might have heard about evolution, you know, like when monkeys evolve into humans. Well, plants go through evolution too.

Basically, evolution is when a parent gives birth to a child that can do something different from it. Also, it must continue over a few generations. For example, let’s think of our example with the apple and durian tree. If it makes a baby that can have big, sweet appledurian fruits, then this could be a new evolution. However, to become a real evolution, the babies of the new appledurian tree must also have big and sweet fruits, and the babies after that. Basically, it must continue over a few generations. This is an example of a good evolution. There are also bad evolutions. For example, there could be an appledurian tree that has small and spiky fruits, which is bad. However, most plants are willing to take the risk, because they don’t want to stay the same forever.

This is how other living things evolve too. Just give birth to a baby that has some strange ability, and it MIGHT just become a new evolution. And if you’re lucky, that evolution will stay on for hundreds and thousands of years. So maybe, just maybe, there COULD be appledurian trees with big and sweet fruits, and they will stay here for millions of years!

(Before I end things of, I am afraid that I will have to say that appledurian plants don’t exist. Yes, it is very sad, but it cannot be helped.)

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