Hi everyone, welcome to today's lesson.

I'm Mrs. Horan, and together we're going to find out all about leaves and the special ways they have become adapted to survive in their habitats.

Today's lesson is part of the Evolution and Inheritance unit.

The lesson is called More About Plant Adaptations, and we will be learning all about the special adaptations plants have to survive in different habitats.

The outcome for our lesson today is to describe the key features of a plant that is adapted to suit its habitat.

This lesson builds on what you already know about adaptations of plants and other living things, and is part of our big learning question, why are there similarities and differences between living things? These are the keywords that we're going to be focusing on today.

Habitat, adaptation, survive, photosynthesis and environment.

Now, you probably already know what some of these mean, but some of them might be a bit less familiar.

We'll make sure to have a really good look at each one as we come to it during the lesson so you'll be able to understand them all yourself by the time we finish.

Here are some explanations of the keywords.

Now, as I said, our new words will be explained as we come across them, so you don't need to look closely at these now.

They're just here as a handy reminder in case you need to come back and check anything later.

Our lesson today is divided into two parts.

Let's get started with the first part, leaf shapes.

Some children are talking about leaves.

You can see we have a few different types of leaves here on screen, and you'll probably have seen plenty more yourself outside in all different sorts of shapes, sizes and colours.

Andeep says, "Why are all these leaves "such different shapes?" Izzy says, "I think it depends "on what habitat they grow in." Jacob says, "I think they can grow "to whatever shape they want." What do you think? Do you agree with Izzy or with Jacob, or do you have a different idea completely? You might want to pause the video here for some thinking time, or perhaps to share your ideas with a partner.

Let's find out about these differences between leaves, then.

Now, like other living things, plants have special features or adaptations that help them to survive and grow in their habitats.

We have a couple of key words in that sentence there, so let's take a minute to think about what those mean.

Adaptations are special features of a living thing that help it to survive in its habitat.

For example, you might know that polar bears have thick, warm coats of fur to help them stay warm in very cold environments, or that holly leaves have spikes to help prevent them getting eaten by hungry animals.

You can see some spiky holly leaves in the picture on the right below.

The other key word we have in that first sentence is habitats.

You probably already know now that habitat is a place where a plant or animal lives.

Habitats can be large like forests or deserts, or they can be small like ponds or even the damp bit of earth underneath a rock.

We know already that living things all have adaptations that help them to survive in their specific habitats.

And the shape of a plant's leaves is an adaptation that can help them to survive and reproduce.

You can see three very different types of leaves in the picture there.

They all look really different from each other, being different shapes, sizes, and even different shades of green.

Before we go on, let's have a quick check for understanding to see how you're doing.

What is the scientific name for the special features that plants have that help them to survive in their habitats? Is it A, characteristics, B, attributes or C, adaptations? Great, it is adaptations.

All plants have special adaptations that help them to survive in their habitats.

Leaves are the parts of the plant that make food using sunlight, carbon dioxide and water.

This process is called photosynthesis.

Now, you've probably spotted that that word photosynthesis is another key word, and it's quite a big one, isn't it? Photosynthesis is the name we give to the process plants use to make their own food.

The first part of the word, photo, means light, just like photograph is a picture made of light.

Synthesis or to synthesise means to put together or combine something.

So altogether, that word photosynthesis means bringing together light with carbon dioxide and water to make food for the plant.

Leaf shapes and sizes are adapted to allow them to get as much sunlight as possible so that they can carry out this process of photosynthesis.

This means that plants in different habitats with differing levels of sunlight have adapted different types of leaves.

Plants that grow in very cold, snowy environments often have very thin, needle-like leaves.

Environment is our final key word for today, and environment is the surroundings or the conditions that an animal or plant lives in.

So the plant you can see in the picture here is growing in an environment with low temperatures and lots of snowfall.

You can see it has long, very thin leaves that look a bit like needles.

These special leaves help snow to fall off easily, instead of sitting on top and making the plant too heavy.

That way, sunlight can still reach the leaves for photosynthesis.

Let's see how we're doing with another quick check for understanding.

Which plant has leaves that are adapted to help a plant survive in very cold, snowy habitats? Do you think it's plant A, plant B or plant C? So the leaves on plant A are the best adapted for survival in a snowy habitat because they are thin, and so snow won't gather on top of them and weigh them down.

Plants that grow in very hot habitats where there is plenty of sunlight often have leaves that are very small or thin.

Large leaves can dry out very quickly in hot, dry conditions, so having thin leaves helps to prevent the plant from losing too much water.

You can see in the pictures of desert plants here that they have very small and thin leaves.

Some plants that grow in the rainforest have very large leaves.

In rainforest habitats, there is lots of rain and very warm weather.

There are lots of plants living in the rainforest, which creates shade.

Having large leaves helps these plants to compete for sunlight.

Have you ever walked under a leafy tree on a hot sunny day and noticed the shade? Maybe you've even sat under a tree because of this shade to get out of the hot sun.

Well, in the rainforest, that's what it's like for the plants growing under the taller trees, which are closer to the ground.

The taller plants have leaves which block out a lot of the sunlight from those below.

The larger a plant's leaves are, the more light it can get in such a crowded environment.

So if it has bigger leaves, it's more likely to be able to catch some of that sunlight that filters through the gaps in the leaves of the taller tree.

Time for another quick check in on our understanding.

Which plant has leaves that are adapted to help a plant to survive in a warm, crowded habitat where lots of other plants are competing for sunlight? Is it plant A, plant B or plant C? Well done.

Plant B has leaves that are the best adapted for warm, crowded habitats like rainforests because it has very large, flat leaves.

Some children are talking about plant adaptations.

Jun asks, "How do plants get their adaptations?" Lucas says, "I think they can just grow "whatever shape they need to so they can survive." What do you think? Do you agree with Lucas, or do you think plants get their adaptations in a different way? You might want to pause the video here for some thinking or discussion time.

So plants can't choose their leaf shape or decide to change themselves.

Plant adaptations are inherited characteristics.

This means they're passed on from one generation of a species to another.

You might remember that this is the same for animals.

They inherit their adaptations from their parents.

Rainforest are very wet and rainy places, which can cause problems for plants with large flat leaves.

The weight of a lot of water pressing down on a leaf can cause the stem to break and the leaf to fall off the plant.

Many leaves have adaptations to help water drain away quickly from the surface of leaves.

Can you see how the shape of these leaves might help water to drain from them? We have three different rainforest plants here.

Look carefully at their shapes.

What adaptations can you see that might help them? Hold onto your ideas because we're going to carry out an investigation to find out more about this in just a moment.

Before we do, let's have one more quick question.

Which of these adaptations would help a plant to survive in the rainforest? And we have A, thin, needle-like leaves.

B, colourful, sweet smelling flowers.

C, large leaves, which water drains off quickly.

And D, thick trunks for storing water.

So for this one, we were looking for answer C, having large leaves which water drains off quickly is a helpful adaptation for survival in a rainforest habitat.

So we've done a lot of learning, let's tackle a task.

Follow the instructions below to investigate how the shape of leaves may or may not help them dry quickly after rain.

You will need to record your observations in the table as you carry out the investigation.

So let's go through these instructions.

First, cut out and fold your leaf templates.

There are four of them all together.

Solid black lines need to be cut and any dotted lines need to be folded.

There are four leaves for you to create.

Two of them will need to be folded.

They look like this.

This one, we fold down the middle.

And this one, we fold a bit like a fan, sort of backwards and forwards.

There are two more that won't need to be folded.

That's these two, a big flat one and this one here.

Now, it's a good idea to use cereal box card or other similar food packaging for this as it has a shiny, water resistant surface so it'll stop the card from just absorbing all the water.

Next step is to hold your leaf at the end where it would join the stem, like this.

I like to hold it sort of level like it would be on the plant.

Step three, use a pipet to drip water all over the surface of the leaf and observe what happens.

You should do this over a tray or a plate so that any water that drips off doesn't go everywhere, and it's really easy to clean up afterwards.

Trays like this that we use for classroom storage are good, or something smaller.

These trays that are often used for food packaging are very useful for this activity.

And step four, record your observations in the table.

Let's take a look at the table we need to use.

And here is our table.

You can see it has a picture of each leaf shape in the first column, and then some space to write your observations in the next column.

You should carefully observe what happens to the water as you sprinkle it on the surface of each leaf with your pipet, and write down what you can see here in the table.

Pause the video now to out the investigation.

Write down your observations, and come back when you have finished.

Welcome back.

What did you find out? Did you observe any differences between the different leaf shapes? Here's what I found out when I carried out the investigation.

For leaf shape one, this one, I noticed that water quickly fell to the middle of the leaf and dropped off the end.

Almost all of the water dropped off.

There were only a couple of tiny droplets left on the leaf.

Leaf shape number two, this one that looked like a fan.

Some water dropped straight off the top edge of the leaf, which was pointing downwards.

Other water fell onto grooves on the leaf and then dropped of the end.

Now, leaf shape number three, this big, flat one, lots of water pooled and stayed on the top of the leaf.

Eventually, the amount of water got heavy enough for the leaf to bend, and some water dropped off the end, but there was still a lot left on the leaf.

And leaf shape number four, which was this one, some water fell through the gaps in the leaves, but not much.

Lots of water pooled on the surface of the leaf and didn't roll off.

Is that similar to what you found out? Let's move on to part two of our lesson, rainforest leaf adaptations.

Plants that grow in rainforest habitats often have leaves that are adapted in different ways to help water drain off them.

Many plant leaves in the rainforest have a drip tip, which is a pointed end that helps water to drain off the leaf.

Can you see the drip tip on the end of the leaves in the photographs here? It's that little downward pointing bit at the very end.

It's a very similar shape to this leaf that we tested.

You might have noticed that water droplets rolled down the leaf and dropped off this tip very easily when you carried out your investigation.

The leaves of Monstera deliciosa, known as the Swiss cheese plant, have gaps and holes so that rain falls through rather than pooling on top.

Like many other rainforest plants, they also have a waxy surface so water rolls off easily.

Fan palms have concertina shaped leaves that water drains away from easily, so they have leaves that are a similar shape to the paper fans we sometimes make ourselves when it's really hot, or to this leaf that we tested during our inquiry.

Can you see how it looks like the leaves are folded? These leaves also have a large surface area for gathering lots of sunlight.

Time for another quick question.

Which of these adaptations would help plants in rainy habitats to dry quickly after rain? We have A, flat round leaves, B, pointed leaf tips, C, holes in leaves, D, waxy surface on leaves, and E, absorbent surface on leaves.

Which do you think it is? There were three correct answers here.

Did you spot them all? They were B, pointed leaf tips, C, holes in leaves, and D, a waxy surface on leaves.

All of those would help plants in rainy habitats to dry quickly after rain.

Some children are talking about plant adaptations.

Sam says, "I planted some Swiss cheese plant seeds "in a pot in my house.

"Will they still have large leaves with holes in "like the ones in the rainforest?" That's a good question.

Alex thinks, "No, there's no rain in your house "and there aren't lots of other plants "to compete with for sunlight." Aisha says, "I think it will depend "how much light it can get inside." What do you think? This will be a good place to pause the video if you want a bit of thinking time for this tricky question.

Leaf shape is an inherited characteristic.

It's an adaptation which is passed down from one generation of a plant to another.

So Sam's seed will grow leaves with a similar shape to its parent plants.

Let's have another quick question.

Why are the leaves of different species of plants different shapes? Do you think it's A, each plant inherits its leaf shape from its parent plants.

B, each plant chooses to grow in the best shape for its environment.

Or C, each plant can decide what type of leaves it wants to suit its habitat.

Great, the leaves of different species of plants are different shapes because each plant inherits its leaf shape from its parent plants.

Sofia has drawn a diagram of one of the leaf shapes she tested.

She has added labels to show its adaptations.

So you can see she's labelled the groove down the middle of the leaf, the pointed tip and the large flat surface.

Each of these leaf adaptations helps the plant to survive in its rainforest habitat.

Scientists often use label diagrams like this to record their ideas because they're clear and easy to understand.

We're going to use one too in a few moments.

First though, let's have one more quick check for understanding now before we head into our final task of the lesson.

Can you decide what word is missing from this sentence? Scientists can use labelled scientific to record their ideas about leaf adaptations.

What word do you think could complete that sentence? Our missing word is diagrams. Scientists can use labelled scientific diagrams to record their ideas about leaf adaptations.

Now, for our final task today, design a super leaf that is the best possible shape for surviving in the rainforest.

Think about the adaptations you've learned about today and how they could be combined on one leaf.

Record your ideas with a diagram with labels to show the adaptations of the leaf.

Your diagram should look a bit like Sofia's, with the leaf shape drawn and each adaptation label to show how it helps the plant to survive.

But it will probably be a different shape to the leaf Sofia drew.

Pause the video now and have a go at designing your super leaf.

How did you do? I wonder if your leaf looks anything like Aisha's.

Her leaf has a groove in the middle so water falls down and towards the drip tips.

It has a tip pointing downwards at the end to help water drain away.

It has an extra drip tip in the middle of the leaf.

It has a large, mostly flat surface to collect lots of sunlight.

And there are gaps in the leaf so some rain can fall straight through.

That brings us to the end of our lesson today.

You've done a great job investigating leaf shapes and thinking about helpful adaptations.

Let's recap our key learning points from this lesson.

Plants have special features or adaptations that help them to survive, live and grow in their habitats.

Leaf shape is an adaptation that can help plants to survive in their habitats.

And scientists can record their ideas using labelled scientific diagrams. Thank you so much for joining me today to investigate leaf adaptations and how they help plants to survive in their habitat.

I hope you found this lesson as interesting as I did, and you learned some great new facts to share with others.

I'll see you again next time.