Lesson video

Welcome to lesson Number 6 in the Ecosystems Unit.

This lesson is all about pollination and human food security.

My name's Mr. Jarvis and I'm going to be teaching you today.

During the course of today's lesson, you should be able to describe the importance of pollination for food production.

During the lesson, there are five key words that we're going to be looking at.

They are: producer, pollen, pollination interdependent, and food security.

Here are the definitions of those words coming up on the screen.

You might want to pause the video at this point just so that you can have a read through the the definitions of these keywords for yourself.

But don't worry because we will be going through them as we go through the lesson.

Today's lesson is broken down into three parts.

First, we're looking at how organisms rely on producers for food.

Then, we're going to look at flower structure and pollination.

And finally, we're going to look at the role of pollination in providing food security that's providing enough food for humans to eat.

So if you're ready, let's start with the first part of the lesson, which is relying on producers for food.

Plants are producers.

That means that they make their own food and they do this using light, water and chemicals from their surroundings, mainly from the soil.

All animals, including humans, are consumers and they rely on the producers for their food.

So you can see in the picture we've got some sheep eating some heather, a plant, and a human eating some rice from a coconut.

Without producers, animals wouldn't be able to survive because there wouldn't be any food for them to eat.

Humans eat lots of different sorts of food.

You may eat some or all of these food types: meat, fish, bread, cereals, fruits and vegetables.

The one thing that's in common is that all of that food comes from a producer.

Let's investigate that a little bit further.

So food chain diagrams can be used to help show us where the food we eat comes from.

I've got a picture of beef burgers on a barbecue.

Beef burgers are made of beef.

Beef comes from cows.

Let's look at the food chain.

Grass is eaten by cows.

Cows are eaten by humans.

Grass is a producer.

It makes the food.

Cows and humans are both consumers.

So you can see that the cow gets its food from the grass.

The grass is the producer.

What about a salmon lunch? Here's some salmon on a plate.

What about the food chain diagram for the salmon? Well, algae is eaten by zooplankton.

Zooplankton are eaten by shrimps.

Shrimps are eaten by salmon, and salmon are eaten by humans.

So the producer in this food chain diagram is the algae, and the consumers are the zooplankton, the shrimp, the salmon, and the human.

You can see that although we're eating a salmon, the salmon has got its food from the algae.

The algae have made the food for the food chain.

So let's check to see how well you've understood that first section.

Here's some information.

Some humans eat bacon from pigs and pigs eat maize.

Which of the following options of food chain diagrams is correct? Is it A, B, C, or D? I'll give you five seconds, but you can pause the video if you want to and then press play when you're ready to start.

The correct answer is C, maize is food for pigs.

Pigs are food for humans.

The important thing is that the arrows are pointing in the right direction.

Remember, the arrows mean it's food for.

So maize is food for the pig and the pig is food for the human.

Well done if you got that right.

Let's move on to a practise task.

Alex and Laura talk about what they had for lunch.

Alex had a school lunch of a roast beef dinner, and Laura had a packed lunch of a salad.

What producers were present in the two meals? Do the lunches contain any consumers? If so, write down a food chain diagram to show where the consumer's food came from.

There's a hint here that beef comes from cows.

You'll need to pause the video at this point, and then when you're ready, press play and we'll check to see how well you've done.

Good luck.

So how well did you do? Alex had his roast beef dinner for his school lunch, and Laura had a packed lunch of a salad.

What were the producers in Alex's meal? Well, the producers were wheat, which made the Yorkshire pudding.

well done if you got that one right, 'cause that's a tricky one to get.

There's also carrot, peas, potatoes.

In terms of a consumer, the beef comes from a cow.

The cow eats grass.

So the food chain diagram you should have written is grass, is food for a cow is food for a human.

Well done if you got that right.

Laura had a packed lunch of a salad.

The producers here are cucumber, tomato, lettuce, spinach, and there are no consumers in Laura's lunch.

Well done if you got those right.

So we are now going to move on to the second part of the lesson, which is all about flower structure and pollination.

So if you're ready, let's move on.

So all consumers, including humans, depend on producers for food, and that means that we also depend on producer's ability to reproduce to make more producers.

Most crops, vegetables, and fruits that we eat are made by plants that reproduce using flowers.

So here's a picture of some blossom flowers on an apple tree, and each of those flowers has the potential to become an apple.

Flowers make pollen and grains of pollen carry the genetic material between flowers, which enable flowers to reproduce.

Here we've got a picture of a bee on a flower, and you can see the pollen grains in the air and the pollen grains on the bee itself as well as on the flower.

The flowers contain the male and the female reproductive organs of the plants.

There are lots of different types of flower, however, they have some common parts.

We have anthers, they're male parts of a flower and they make the pollen.

And we have the stigma, which is a female part, and that's sticky to help collect pollen during reproduction.

They've also got an ovary that's also a female part, and that contains the ovules that receive the genetic material from the pollen, and eventually that's where the seeds are produced.

So here's a drawing of the flower.

You can see there's the anther, the male part of the flower that produces the pollen.

We've got a female part of the flower, the stigma, which is the sticky part, and which is where the pollen sticks, and also a female part, the ovary and the ovules, which become the seeds which are located further down the flower.

There's also a petal.

The petal is the pretty coloured part of a flower and that's used to attract insects.

So let's check to see how well you've understood that section.

So join the boxes to show whether each part of the flower is male or female and the job that it does.

So use some lines to connect those boxes to describe whether their parts are male or female and the jobs that they do.

You'll need to pause the video at this point and then come back, press play, and we'll check your answers.

Good luck.

So how well did you do? First of all, let's look at the male part.

The male part is the anther.

The anther makes pollen.

The female part is the ovary, and that contains the ovules that receive the genetic material and also the female part is the stigma, and that's sticky to collect pollen.

Well done if you've got those all correct.

So pollen is made in the anthers.

That's the male part of the flower.

Lots and lots of pollen grains are released by the flower, and that's because they need to get from the anthers where they're made to the stigma of the same type of plant.

There's the anther, the bright yellow part, and there's the stigma which the bees climbing onto.

The process of getting pollen from the anther to the stigma is what we call pollination.

And the pollen grain travels to the ovary and fertilises the ovules that then become seeds.

Some producers did not have colourful flowers or petals.

Grasses and cereals such as wheat have the same reproductive organs, but they produce much larger amounts of pollen.

So here are some pictures of grass, wheat and rice, all of which don't have those colourful flowers.

There are two main ways that pollen can get transferred from the anthers to the stigma.

The first is via insects.

We call that insect pollination.

And the second is via the wind, and we call that wind pollination.

Let's go into a bit more detail about what each of those mean.

So insect pollination is where flowers attract insects by their coloured petals, their lovely fragrance smells, and by rewarding insects with a drink of sugary nectar.

The anthers of insect pollinated plants produce relatively small amounts of sticky pollen, and when the insect lands on the flower, the pollen sticks to their body.

As you can see with this picture of a honeybee, which is absolutely covered in bright yellow pollen.

The insect flies off to another flower and pollen from the body sticks to the stigma and pollination takes place.

Wind pollination is different.

The anthers of wind pollinated plants hang outside the flower, and you can see that on the diagram in the bottom right hand corner of the screen, the anthems, the bits that produce the pollen are hanging outside of the flower.

They produce millions of light pollen grains that are carried by the wind.

Wind pollinated plants have stigmas that are really large and feathery.

They act a little bit like a net.

They catch the pollen grains and when they the pollen grains land on the stigma pollination takes place.

Let's check to see how well you've understood that section.

True or false? Lucas has labelled his picture of a flower correctly.

When you've decided whether that's true or false, decide why that's your answer.

Is it A, because this is the part of the flower that produces pollen or B, this is the stigma and this is where the pollen sticks when pollination takes place.

I'll give you five seconds or you can pause the video if you need a bit more time to think about your answer.

How did you get on? Let's see how well you did.

So the correct answer to the question is false.

Lucas has not labelled his picture of the flower correctly, and the reason for this is that he's a label line is actually pointing to the stigma, and that's where the pollen sticks when pollination takes place.

Remember, the anther is the part of the flower that produces the pollen.

Well done if you got that right.

Let's do a practise task.

I'd like you to look at the cards below, sort the cards into piles of the features seen in insect pollinated plants and wind pollinated plants.

If you haven't got the cards, you can do a table with two headings, insect pollinated plants and wind pollinated plants.

And just write a list underneath each of the headings.

So the cards say anthers and stigma are found inside the flower.

Colourful petals, large feathery stigmas catch pollen grains, scented petals, small amounts of sticky pollen produced by anthers, nectar, anthers hang outside of the flower and large amounts of light pollen produced by anthers.

You'll need to pause the video, write down your answers or sort your cards, and then when you're ready, press play and we'll check to see how well you did.

Good luck.

So hopefully, you've got two piles of cards or you've made two lists: one of insect pollinated plants and one of wind pollinated plants.

Let's check your answers.

So the pile of insect pollinated cards should be: scented petals, nectar, colourful petals, anthers and stigma found inside the flower and small amounts of sticky pollen produced by anthers.

Well done if you got all five of those.

The wind pollinated plants, so plants like grasses have anthers hanging outside the flower, large amounts of light pollen produced by the anthers and large feathery stigmas to catch the pollen grains.

Well done if you've got those right too.

That brings us to the final part of the lesson today, and that's all about pollination and food security.

So if you're ready, let's move on.

After pollination, genetic material from pollen is combined with genetic material in the ovules, and that process of combining the genetic information is what we call fertilisation.

Fertilised ovules develop to form seeds and those seeds are the basis of new plants.

However, those seeds also form an important part of humans' diet.

Rice, maize and wheat are all seed crops that humans eat and they make up 51% of the food that's eaten across the world.

Seeds are often surrounded by fleshy structures called fruits, and those fruits protect the seeds.

Here, you can see some pictures of the seeds that are protected by fruits.

We've got seeds within an apple and seeds within a kiwi fruit.

Many fruits are good sources of food for animals including humans.

The plantain fruit is one example.

They're a staple part of the diet of many people around the world.

All consumers, including humans, depend on producers for food.

We've seen that in the first part of today's lesson.

Many of the crop plants that we eat depend on insects, and in particular bees, to pollinate them.

Only when the crop plants are pollinated can they produce seeds and fruits, and this is an example of how plants and animals are interdependent, i.

e.

, they rely on each other.

Plants rely on animals to pollinate them, and animals rely on plants for food.

Some plants also depend on animals consuming fruits.

Seeds can pass through the animal's digestive system undamaged, and they germinate in the animal's faeces and grow to make a new plant.

This dispersal of seeds by animals helps populations of plants to spread out and grow in different areas.

Here's a chance to check what you've understood in that section.

Which of the following statements are correct? A, plants produce fruit so that humans have food.

Plants produce fruit to protect seeds or it helps plants when consumers eat fruits and disperse the seeds to new places.

I'll pause for five seconds.

If you need a bit longer, then you can always pause the video and press play when you're ready to carry on.

How did you get on? Well, let's see.

The correct answer is B, plants produce fruit to protect seeds and C, it helps plants when consumers eat fruits and disperse the seeds to new places.

Well done if you've got both of those answers correct.

Demand for food is increasing as the human population grows, and that raises questions about food security.

Food security is being able to produce enough food to feed the human population.

Bees and other pollinating insect populations having comparison declined in the past 50 years, and this is a result of destruction of insect habitats, the introduction of pests, diseases, and humans' use of insecticides.

It's important to conserve bees and our other pollinators and help them to pollinate our crops, and we can do that in a number of ways.

We can provide a habitat for bees and other insects by planting hedgerows and sowing wildflower seeds so that they have enough food to eat and we can reduce the use of insecticides.

Both of these will help humans to have food security in the future.

Let's check to see how you've understood that last section.

Which of the following is correct? Food security is A, eating lots of different foods from around the world.

B, having food locked away from emergencies.

C, growing enough food to feed the human population, or D, stocking a wide variety of exotic foods in supermarkets.

I'll pause for five seconds while you think of your answer.

You can pause the video if you want longer and then we'll check to see how well you've done.

Good luck.

The correct answer is C, food security is growing enough food to feed the human population.

Well done if you got that right.

Now, it's time for our final practise task, today.

The population of bees is getting smaller quickly.

Izzy thinks that this could cause the human population to decrease.

Write a short paragraph to explain whether Izzy's right and give a reason for your answer.

You'll need to pause the video at this point, and then when you're ready to move on, press play and we'll check your answers.

Izzy thought that the population of bees getting smaller quickly could cause the human population to decrease.

Izzy is correct, and that's because humans rely on many crops for food that are pollinated by bees.

If the crops aren't pollinated, there's less food for humans to eat and the population could decrease.

Well done if you got that correct.

Finally today, here's a summary of what we've learned.

We've seen that producers make their own food.

All consumers, including humans, depend on producers because they make the food for the rest of the food chain.

We've seen that pollination is the process of transferring pollen from where it's made in the anthers of flowers to the stigma.

And after pollination, plants produce fruits and seeds which form food for humans.

Many plants depend on animals such as insects for pollination and also on animals such as birds to disperse their seeds, and this is an example of how plants and animals are interdependent.

Finally, we've looked at how insects are important in ensuring that there is food security for humans, and that food security is having enough food to feed the human population.

It's been great teaching you today.

I hope you've enjoyed today's lesson and I look forward to seeing you all again soon.

Take care for now.

Bye-Bye.