Lesson video

Hello and welcome to this lesson from the unit Reproduction in Plants.

The title of today's lesson is Flower Structure, and we're going to be looking at how plants reproduce sexually and how they use their flower, which includes the sexual organs of the plant, in order to produce offspring.

My name's Mrs. Barnard and I'm going to be taking you through today's lesson.

So by the end of today's lesson, you should be able to describe the function of the male and female reproductive structures in a flowering plant.

So we've got our keywords for today's lesson.

I'm gonna put a slide up with the definitions, so if you want to pause the video to write them down, you can.

Otherwise we will be defining them as we go through today's lesson.

So our keywords today are sexual reproduction, ova, pollen, stigma, and anther.

Our lesson today is in two parts, sexual reproduction in plants, so we're going to look at how a plant reproduces in order to make offspring, and then the reproductive system, so the male and female parts of the reproductive system, and what the jobs of each of those parts are.

So let's start with the first part of today's lesson, which is sexual reproduction in plants.

We're gonna start with a little bit of a recap, so hopefully you've covered this before.

So all living organisms, including plants, carry out some common processes.

So how many of them can you remember? You might want to talk to somebody next to you.

There're seven.

So I'll pause while you have a think.

Okay, so let's see how we got on.

So we've got movement, reproduction, sensitivity, growth, respiration, excretion, and nutrition.

And some of you might remember the mnemonic that we use to remember that, which is MRS GREN.

Now the common process that we're gonna be focusing on today is one of those Rs, which is reproduction.

Because plants are living organisms, they all reproduce, and they can reproduce by sexual reproduction.

So what that means is that two parent plants, through the process of reproduction, will form a seed, which is the first part of the development of offspring.

So why is it so important to learn about reproduction in plants? And it's because plants are producers, which means that they produce something, they make something.

And what plants do is they make their own food, and they do that from carbon dioxide, water and using the energy from sunlight.

So it's quite amazing really, like, we can't do that.

We can't make our own food, we have to rely on other things for our food, but plants can just take gas out of the air and water and sunlight energy and they can make their own food.

So it's important to know about that 'cause it's just amazing, and it is a process called photosynthesis, which lots of you will have heard of before.

But it's also important for us because it's where all the food in the food chain comes from.

Now, plants to start with use that food, their own food that they've made, for growth.

So you start with a little oak seedling in an acorn and it grows into a seedling to start with.

And then through that process of using carbon dioxide and water and sunlight as energy, it turns into a massive tree.

So all of that growth is made because it can make its own food.

And growth of plants is important because we're going to use those plants for food for all of the consumers on Earth, and that includes humans, we rely on plants for our food.

Without plants there would be no food for animals.

And all of our food is initially made by producers.

So you might think, "Oh well, I've had a hamburger or some chicken, that didn't come from the ground." But the animals that made that, so obviously beef burgers are made from cows, those cows had to eat the grass to start with in order to grow that muscle in the first place.

So as humans, we can either eat the plants straight from the ground, or we could eat meat, which has come from animals that have eaten the plants that have come from the ground.

So we depend on producers.

So therefore we depend on their ability to reproduce 'cause they make more producers when they reproduce.

And most of our crops, like vegetables and fruit, are made by plants that reproduce using flowers.

And here's an example, you might notice in springtime when all of the blossoms start to come up on the trees, and that's the start of plants starting to reproduce.

They're putting their flowers out there in order for pollination to take place, which we'll talk about in later lessons.

But eventually all of that blossom blows off and falls away because the flowers aren't needed anymore.

And it'll be replaced by, in this example, apples.

So why is this so important for humans? Because humans, the world population of humans in 2024, is 8 billion people.

Now that's a number that's quite hard to get your head around, but sometimes when you look at cities and you see the vast numbers of people there, you can sort of understand.

And those numbers are going up and up every year.

And because of that, we need to really think quite carefully about how we're going to feed all of those people.

And as we know that all food comes from plants, we really need to understand plants.

We need to understand how they grow, the conditions they grow in, and how they reproduce.

So therefore our knowledge of plant reproduction is essential to life on Earth.

So time for a quick check.

Why is reproduction in plants so important? So read these four answers and decide which you think help you to support that statement.

Okay, let's see how you got on then.

So without it, there would be no more plants.

So that one is true, that does support that statement.

And, it produces more food which consumers need.

That one is also correct.

It's a process of all living organisms. It is, but that doesn't really tell us why it's so important.

And without it, there would be no more flowers.

Again, that might be true, but it's not why it's so important, particularly to humans.

Okay, time to move on.

So flowering plants can reproduce using sexual reproduction.

So not all plants use sexual reproduction, but that's what we are focusing on today.

And that requires two parent plants to undergo that common process of reproduction to make offspring.

So when the plants reproduce sexually, the two parent plants are required to make offspring, and the offspring will be the same species as those parents and they will look similar to those parents.

So when plants reproduce during sexual reproduction, a seed is formed.

So you have your two parent plants, reproduction takes place, and you form a seed.

Now a seed is a living organism.

It is part of the lifecycle of a plant.

So it follows some of those common processes.

It is the first development stage of the new offspring of the plant, okay? It's made of cells, made of living cells.

And during sexual reproduction, DNA is passed from both parents to form the seed, and that will eventually grow into a plant.

So we've got our two parent plants here, and during reproduction to form this seed, they're both going to pass DNA.

So that seed has got DNA from both of its parent plants.

That seed will then grow into a sprout and then continue to grow into a seedling.

And that seedling is then going to resemble its parents, but it's gonna have DNA from both of its parents if it has been made by sexual reproduction.

So time for another quick check.

Sexual reproduction is when two plants make a seed.

So first of all, do you think that's true or false? And when you've decided, which of the statements below do you think best justifies your answer? So just pause while you make your decision, we'll come back and we'll see how you've got on.

Okay, so let's see what the answer is.

So sexual reproduction is when two plants make a seed.

That is true.

And the statement that best justifies the answer is that two plants each provide half of the DNA to create a seed that will then grow into a seedling.

And that's the important part about sexual reproduction, 'cause we have DNA from two separate adults to form the offspring.

So sexual reproduction in plants uses gametes.

Now gametes is the scientific term for sex cells, and you might have come across this term in a human reproduction topic when we talked about sperm and eggs.

So gametes in plants carry the DNA of each parent, so the same as it does in humans.

The female parts of the plant, they produce one ovum or many ova, so ovum is the singular and ova is the plural, so it means the same thing, it's just that one is many and one is just one.

And the male parts of the plants produce pollen.

So each gamete carries half of the genetic information required to make the offspring.

So half of the genetic information from their parent plant.

And that genetic information is coded for in DNA, and that is packaged into chromosomes.

And those chromosomes have the DNA all wound up, stored inside the nucleus of each gamete.

So there we go, we've got our pollen and our ovum, and inside their nuclei you've got chromosomes, and those chromosomes is all the DNA that's bundled up into those structures.

So, time for another quick check.

Choose the features required for a seed to form in sexual reproduction in plants, okay? So pause the video, we'll decide and then we'll have a look at how you've got on.

Okay, so what did you choose? How many did you choose? Let's see.

So we will need two parents, we will need two sets of DNA, and we will need male and female gametes, okay? And we need all of those things to form one seed.

So let's move on to a practise task.

Sofia looks at a sunflower closely to see it seeds.

Now if you get the opportunity to do this, often people grow sunflowers, so have a look if you're walking past any gardens.

And it is really amazing when you look really closely and you can see those seeds forming inside that flower head.

And Sofia's quite impressed with it.

She says, "Wow! These are the offspring of this plant.

They can be planted to grow more sunflowers." So Sofia has some correct ideas, but she's missed out some key information about sexual reproduction.

So what I would like you to do is I'd like you to write an improved statement to describe the seeds of these sunflowers.

Take her ideas and see if you can put in more of your understanding of sexual reproduction into that statement.

So pause up while you do that and then we'll come back and we'll see how you've got on.

Okay, how did we get on then, have we improved that statement? So we're putting in our knowledge of sexual reproduction.

So the sunflower seed is the offspring of two parent sunflower plants.

So that's one of the things that she missed, saying it was just the offspring of this particular flower.

Both of the plants provided DNA, carried by their gametes, to produce the seed.

And the seed can be planted and will grow into a plant that resembles both of the parent plants.

Now with sunflowers you might find that the parent plants look quite similar anyway, but it will resemble both of them because it has the DNA from both of them.

Okay, so if you've got those key ideas into your answer, then well done.

So it's time to move on to the second part of our lesson today.

And the second part is the reproductive system.

In order for an organism to carry out sexual reproduction, it needs to have a reproductive system, just the same as humans do.

So the reproductive system of a flowering plant is the flower.

So in plants, the male and female reproductive systems are actually together within the same flower.

So the plants are both male and female.

So you can see some pictures here of different flowers, lots of different flowers look different, but they're all the reproductive organs of a flowering plant.

So different flowers all have the same reproductive organs, even though they might look a little bit different.

So what we have here is we have the stamen, so the stamen is the male part of the reproductive system and it's made of the filament and the anther.

The anther contains the pollen, and that's right at the very top of the filament, which is the stalked particle that holds the anther up.

Then we've got the female part of the plant, which includes the stigma, which is this bit that goes through the middle.

Also, the female part of the plant is the style.

So the stigma is held up by the style, which then goes down to the ovary at the base, which contains the ovules.

And then we've got petals, and hopefully you've learned before that petals are there to attract pollinators such as insects, bees, but we'll talk about pollination in later lessons.

So all flowers contain the same reproductive organs, but they can look different.

So here's a daffodil, now hopefully you are all familiar with the daffodil.

And it is the flower.

And you can see, as we cut it open, we can see those parts of the reproductive system inside.

So this is quite cool, maybe you could have a go at this.

So we've got the petals, which are there again, as we've said, to attract the pollinators.

And then we've got the anthers, which are at the top of the stamen, which is the male part of the plant.

And then we've got the stigma, which is the female part, or part of the female system.

And then the other part of the female system is the ovary and the ovules, which are right down there at the bottom.

So we're gonna now look at these a little bit more closely.

So if we take these out and zoom in a bit, we can see that these are the stamen with the anthers at the top.

Now these anthers look a bit different 'cause they're sort of very long compared to that diagram.

And if you look carefully, you can see some really tiny little pollen grains there next to the anthers because that is where the pollen is made and stored.

And then right at the base here we've got the ovary, which is one of the female parts of the plant, and inside you can see quite well if you zoom in here, the ovules.

So the ovules is where the ova are.

So that's where the gametes, the female gametes of the plant are.

And then if we go over to the other side here, we can see the stigma.

Now sometimes it's difficult to see the stigma 'cause it looks like it's similar to the anther, but it is quite distinctively different when you look at it close up.

So you might be able to have a go at this with some flowers that you see around, if it's the right time of year.

So let's see if you can identify the different parts of the flowers from these pictures.

So first of all, in which of these images can you clearly see an anther? So pause while you make your decision, we'll come back and see how you got on.

Okay, let's see how we got on then.

So we can clearly see an anther in that pink flower.

It's that dark pink colour that's in the middle.

And we can see them in B, they look black at the surface here.

But we can't see them in this snowdrop because they're underneath the petals, we can't clearly see them.

And in these images, which one can you clearly see a stigma? So pause while you have a look and then we'll come back.

Okay, so we can clearly see it here, now it looks a bit different here, it's sort of shorter and rounder, it's that thing that's right in the middle that looks light green and a bit stripey.

And we can clearly see in this one, it's that one that goes up through the middle between the anthers with a slightly sort of pinkish top and a light green.

Now, although a dandelion flower will have a stigma, we can't clearly see it in this image.

So each organ of the reproductive system has a different job.

So let's start with the stamen, which is the male part of the flower, and it is made up of the anther and the filament.

And the job of the anther is it produces pollen, which is the male gametes.

And the ovary and the ovules, that's the female part, they make the ova, and that's the female gametes of the flower.

And then we've got the petal.

And the petal attracts pollinators such as bees to transport pollen, and pollination follows in a later lesson.

And the stigma is the female organ part of the plant which collects the pollen grains, so the pollen is deposited here on the stigma.

So time for a quick check.

So choose the incorrect statements from the four listed below.

Okay, let's see what you got.

So we had choices of the stigma produces pollen, ova are produced in the ovules in the ovary, petals attract pollinators, and an ovum is a male gamete.

So the incorrect ones are, the stigma produces pollen, because that's produced by the anther, and the other incorrect one was that the ovum is the male gamete, because the pollen is the male gamete, okay.

So time for your first practise task.

So what I'd like you to do is match up the key word with the correct definition.

So pause up while you do this and then we'll come back and we'll see how you've got on.

Okay, let's see how you got on then.

So match the key words to the correct definition.

So pollen is the male gamete of a plant.

Ova is the female gametes of a plant.

Stigma is part of the female organ of a plant that collects the pollen, and the ovule is part of the female organ of a plant that produces ova.

And the anther is the part of the male organ of a plant that produces pollen.

So if you got all of those definitions correct, then well done.

So your next task is to label this diagram of a flower with the organs that are involved in reproduction with descriptions of their functions.

So very specifically making sure that your descriptions include how they are involved in reproduction.

So this will take you a little bit of time.

So if you pause the video and then we'll come back and we'll see how you got on afterwards.

Okay, let's see how you got on with that then.

So first of all, we have got the anther, now you don't have to do these in the same order, so we'll do them all and then you can mark them as we go.

So we've got the anther, which is the male organ of the plant, which produces pollen, which is the male gametes, and it's part of the stamen.

And we've got the stigma, which is the female organ of the plant, which collects pollen grains.

And then we've got the ovary and the ovules, which is the female part of the plant, which produce the ova, the female gametes.

And then we've got the petal, which attracts pollinators such as bees to transport pollen.

So if you got all of those right, then well done.

You've got a full description there of the reproductive organs of a flower.

So that brings us to the end of today's lesson.

So well done with your work on this today.

Flowering plants reproduce sexually.

Half the DNA is passed from each parent plant to form a seed.

Plant reproduction is important as plants are producers and provide the food that all animals on Earth depend on, including humans.

Flowers contain male and female sex organs, and the reproductive system is called the flower.

The flower has the male organ, the anther, and the female organs, the stigma, the ovary, and the ovules.

Pollen grains carry male gametes and are produced by the anther.

Egg cells, ova, are female gametes and are produced in the ovules within the ovary.

And pollen is deposited on the stigma during pollination.

There's a lot of new words in today's lesson and we'll take them on to future lessons to talk about the processes of pollination and fertilisation.

So well done with your work today.