Lesson video

Hi everybody, it's Miss Simkin back again for your next science lesson.

Let's have a look at our lesson question for today.

I hope you're as excited to start as I am.

This is one of my favourite topics today.

So our lesson question today is how are organisms adapted to live underwater? This is one of my favourite topics because before I became a teacher, I used to be something called a marine biologist and a marine biologist is a type of scientist that studies organisms that live under water.

So this is one of my absolute favourite lessons to teach.

For today's lesson you are going to need please, a piece of paper or exercise book, a pencil, a coloured pencil, and a ruler.

If you don't have those things, could you just pause the video and go and find them for me now, please? Great, these are our star words for today.

So we're going to practise saying them, I'm going to say them, and then I'm going to the point at the screen and you're going to say them and then we're going to talk about what they mean.

Adaptation, marine, oxygen, camouflage, streamlined.

Fantastic.

So adaptation, we know already what adaptation means 'cause we've been looking at adaptation so far in this unit and adaptation is a characteristic of an organism that helps it to survive.

So it's something about that organism that helps it to survive or to thrive in some cases.

Marine means anything to do with the sea, anything relating to the sea.

So when we talk about marine environments, we mean environments under the sea.

When we're talking about marine animals, we mean animals that live in the sea.

Oxygen.

Oxygen is a type of gas that humans and animals need to breathe in in order to survive.

So it's in the air all around us and we breathe it in in order to survive.

Camouflage.

We're going to talk a little bit more about in this lesson.

Camouflage is when an organism can blend in with its surroundings.

So at the moment I'm wearing a black jumper and I've got a white background.

It's not very good camouflage.

If I really wanted to camouflage I'd be wearing something white to the blend in with my wall.

s Of course, animals can't choose what they're wearing, but an adaptation that lots of animals have is that they are the colour of their surroundings in order to help them to camouflage.

And our last star word today is streamlined.

When we describe something as streamlined we're talking about its shape and a streamlined shape is something that can move easily through water or air.

So if you think about the shape of an aeroplane, for example, all aeroplanes are the same shape, they're long and they're normally pointed at the front.

That's a streamlined shape that helps them to move easily through the air.

We're going to be looking at some animals that are streamlined today.

This is what we'll be doing this lesson.

So they're going to start with some recap from last lesson then we're going to look at marine environments and what makes them different to other environments.

Then we're going to look at some adaptations of marine animals, specifically camouflage, how they're adapted to breathe, and how they're adapted to move in their environments.

Let's start with our recap.

These are some animals that we looked at last lesson.

Can you remember what all of these animals have in common? Think about it.

What are the similarities? What did we learn about these animals? Say it to your screen? These animals are all nocturnal.

Well done if you remembered.

That means they're active at night and they also have some similarities in terms of that adaptations.

If you didn't already think of them, can you see if you can remember any of the adaptations of nocturnal animals? I'm going to give you a clue now.

I'm going to do it one more time.

See if you can remember any of the adaptations of nocturnal animals.

Pause the video and write your ideas down now.

Great.

So some of the things that you might have written down if you were catching my clue, I was trying to make my eyes as big as possible for you.

Nocturnal animals, like our cute little sugar glider in the corner and the scary looking aye-aye at the top have big eyes.

They also have bigger pupils.

Both of those things are adaptations that let more light into their eyes and allow them to see in the dark.

Another thing you might have written for our nocturnal animals is that they are all dark coloured.

So we're going back to that word camouflage again, and that helps them to camouflage in a nighttime environment when things are dark.

But then if you remembered those two adaptations and well done if you remembered any of the other awesome adaptations we learned last lesson.

Let's begin by looking at marine environments.

So I've got some facts for you.

Marine environments are actually arguably the most important environments to learn about because they cover the most of our world.

So they make up most of the environments on our earth.

So oceans cover 71% of the earth surface.

So that means only 29% is environments that we find on land.

But as well as covering the most surface area oceans actually contain 99% of the living space because not only do they cover so much of the surface of the earth, but they also go so deep down that the space that they take up is enormous.

So because we live on land and we're land animals, we probably think of land taking up the most space or land being the most important, but actually the marine environment is 99% of the living space on the planet.

And on top of that, what's really exciting about marine environments is that 95% of the world's oceans are unexplored which is really, really cool I think.

So we can explore the world's oceans by swimming down to the shallow beds, by snorkelling, by diving, by scuba diving, which is where you wear like a human would wear a pack of air on their back and they can breathe from it.

We can also go even deeper with things like submarines, but even with all of that equipment, we've only explored 5% of the world's oceans.

95%, that's almost all of the world's oceans are unexplored.

So imagine all of the amazing things that there must be to find in the world's oceans that we haven't found yet.

Very cool Okay, take a mental image in your brain of those facts 'cause I'm about to see if you can remember those percentages and can you fill in the gaps for me? Oceans cover mmm percent of the earth's surface, oceans contain mmm percent of the living space on the planet and mmm percent of the world's oceans are unexplored.

Can you pause the video and complete this for me now? Could write up a full statement and fill in the gap? Pause the video and do that for me now, please.

Fantastic.

Let's see if you got these correct.

If you didn't that's okay.

The exercise is just to help you remember them next time.

So 71% was the first answer, 99% was the second, and 95% was the third.

Give yourself a tick in your different colour if you've got those correct.

If not, that's okay.

Just correct your answer now, if you need some time, then pause the video and do that for me.

So here I have a picture of two environments, the one on the left with a snorkeler in it is a marine environment.

And the one on the right is, well we call them terrestrial environments.

It just means an environment that's on land.

What is the main difference between these two environments? Have a think for me, it's not a trick question.

The main difference is that one is underwater and the other is not, okay.

It might seem obvious, but that difference is really important.

Imagine that you are a human in that terrestrial, that lovely meadow environment on the right you'd have no problems surviving.

In fact, you could sit down and have a picnic and have a lovely time.

What is the problem with a human or an animal like us that lives on land with surviving in a marine environment? What things are we or they going to find tricky? Have a think for me.

The main thing is that there's no air, so we're going to have to find a way to breathe.

The other thing is that we're going to have to swim.

Moving through water is trickier than moving through air.

I don't know if you've ever tried to run on the shallow end of a swimming pool or run through the sea, it's a lot harder running through water than it is just running on the playground.

Those are just some of the challenges that organisms who live in the sea have to overcome with their adaptations.

They have to figure out how to move through water and they have to breathe in a watery environment.

So bear that in mind when we're learning about our adaptations later.

There's another difference that you might have spotted and that's to do with the colour of the environments.

What is the main colour in a marine environment? Shout it to your screen.

Yeah, it's blue or like bluey grey depending on how tropically the sea is.

So that brings us onto our first kind of section of adaptations that we're going to look at.

We're going to look at camouflage.

So we've spoken about camouflage already in these units, but let's revised what camouflage is.

I would like you to find an object around you, doesn't matter what it is.

I've got a blue hairband on here and I want you to try and hide it around the room that you're in at the moment.

I don't want you to hide it underneath something.

You're going to need to put it on top of an object.

So what then would be the best coloured object for me to place this on top of if I want to hide it? Something blue.

If I were to place it on top of a black object, it would be very obvious.

So I'm going to try and find something blue to place this object on.

I want you to pause the video and have a go at doing this too.

So choose an object that's a particular colour and then see if you can hide it on top of something.

Pause the video and have a go at doing that for me now, please.

Great.

So that is just a quick demonstration of how camouflage works.

Camouflage is when something matches the colour of its surroundings and it helps animals to stay hidden.

We've got three marine animals on our screen here.

If you know what they are you can say them to a screen.

We've got a dolphin, a sea lion, and a shark.

All of these marine animals have that kind of bluey grey colour so that they can camouflage, so that they can blend in with their environment.

However, lots of marine animals take this camouflage a step further.

So you can see this shark on the screen.

What colour is it on the top of its body? It's grey, but what about the bottom of it#s body? It's white.

And this is something we see really commonly in marine animals.

They're a darker colour on the top and a lighter colour on the bottom.

So here's a drawing of a shark, that just makes us a bit more clear.

So you can see the dark colour on the top and the light colour on the bottom.

Have a look closely at this picture.

There's a line halfway through it where the water is.

I wonder if that helps to give you an idea of why sharks and other marine animals are coloured this way.

Just take a moment to have a think for me.

So it is to do with which parts of the body are outside of the water and which parts of the body are inside of the water.

It's roughly to do with that.

I'm going to show you some pictures now, which hopefully explain this in a bit more detail.

So have a look at the first picture that says from above, you can see it's a picture of a shark, a small reef shark.

And this is a picture that's been taken as if we were looking down from above the shark and you can see that that dark colour on top of it is quite similar to the colour of the sea floor, especially that corner that's a bit darker over by the coral.

If the top of the sharp was white, that really bright white colour would be much easier to see.

It would stand out against the background.

So that dark colour camouflages the shark to the sea floor when we're looking down from above.

If we look at the next picture, it shows a shark if we're looking down from below.

So everybody just imagine that you are at the bottom of the sea and you're looking up at the moment, you're looking down from below, what can you see? Probably your ceiling and your light bulbs.

But if we were in the sea and there was a shark swimming above us, it would look a bit like in this picture and that white bottom of the shark is to camouflage it with the light that's coming from the surface.

So you can see in that picture that you can see the bright sunlight shining into the water and so when you look up, you see that like white sunlight and the sharks white belly helps to camouflage it with that white sunlight coming from the top.

So essentially this really clever bit of camouflage means that no matter where the animal is, if it's at the surface of the water or in the middle of the water column, or maybe down at the bottom, that it still is camouflaged as possible.

So the dark grey means that when we're looking down on the shark, so whether we're predator or prey it's harder to see it because it camouflages with the bottom.

What does it camouflage with when we're looking down? Say it to your screen.

The bottom ,the sea floor.

When we're looking above the white belly is useful because it camouflages it with what? The light coming from the sun.

Can you now please draw this picture of a shark? A rough sketch is absolutely fine.

And I want you to add two labels to explain how it's camouflaged.

So what does the grey colour help it camouflage with and what does the white colour help that camouflage with? Have a go and if you're finding it tricky, you could always go back and watch the last bit of the video again.

Pause the video and have a go for me now, please.

Fantastic.

Let's see if you got this correct.

So I've added an arrow that says dark colour on top to camouflage with the sea floor and then an arrow on the bottom that says light colour on bottom, you might have written white colour, to camouflage with light coming from the surface or light coming from the sun.

Well done if you've got those correct, if you need to correct or to edit your answers, that's okay.

Just pause the video and do that for me now, please.

Fantastic.

We've looked at camouflage, now let's look at our next set of adaptations, all about breathing.

So we've already spoken about how there isn't oxygen in the air underwater so animals that live underwater have two ways of getting around this.

Either they come up to the surface and they breathe oxygen from the air and they come out of the water to do that.

Or they have a way of extracting oxygen from the water.

So we're going to look at that first way now.

This is a picture of a shark again, a shark is a type of fish and you can see that the shark has these slits here on the side of it and they are called gills.

What are they called? Set your screen.

Gills.

So gills are special breathing organs and they're used by fish and some marine animals like crabs.

And they work because ocean water has oxygen dissolved in it and an animal with gills is able to extract or take out that oxygen from the water and breathe it in.

So they actually take it in through their mouths and then it comes out again through their gills like that and this means that they are able to actually breathe underwater, which is really great when you live under water.

There are other marine animals that don't have gills, so they can't breathe underwater.

So things like sea mammals like dolphins or turtles, whales, they can't breathe under water.

They have to come up to the surface in order to breathe.

They have some things to help them do this.

The first is something called a blow hole.

So you see mammals like dolphins have something called a blow hole, and it is a hole on the top of their body that they breathe through.

And what that means is they can come up just to the top of the surface and breathe really efficiently through that hole.

They don't have to come up, open their whole mouth and then go back down.

They can just swim at the top and just their blow hole can be above the water and they can breathe through that.

Animals like turtles don't have a blow hole, so they need to surface.

You can see this little turtle poking its head up into the water, but all of these kinds of animals can hold their breath for a really, really long time and that's really important because otherwise they'd have to come up to the surface to breathe very often.

So we're going to talk about a particular marine animal that can hold its breath for a really long time now.

Just take a minute to have a little giggle if you want to at this animal on the screen, because it does have a very funny looking nose.

This animal is called an elephant seal and you can probably guess why because of its nose that looks a bit like an elephants truck.

Now, before I tell you how long an elephant seal can hold its breath for, we're going to do a quick test and we're going to see how we can hold our breath for.

So I've got my phone here and I'm going to time myself on my phone.

I'm going to go to the stopwatch and I'm going to press start.

Watch me do it first and see how long I can hold my breath full.

You can hold your breath along with me.

And then if you want, you can pause the video and you can go and find something around your house to time yourself with too.

Maybe you have a stopwatch at home which would be great, but any kind of watch or clock you could time yourself on and count the seconds or you might have somebody who's phone that you can borrow.

So in fact, I'm going to make myself full screen for this and we're going to see how long I can hold my breath for.

If you want to do it with me, then we're going to start in, take a big deep breath, three, two, and one.

So that was about 48 seconds.

I think if I wasn't talking before I started and if I wasn't getting the giggles, I might've been able to do it for a bit longer.

Why don't you have a go now and see how long you can hold your breath.

See if you can get to over a minute, pause the video and have a go at doing that for me now, please.

I hope that you had a go trying to hold your breath, whether you did it with me or you just went and had a go by yourself then.

If you managed to get over a minute, well done, you've got a good pair of lungs on you.

Humans can only hold their breath for a couple of minutes.

So what that means is if we were to try and to live in a marine environment, we would have to come to the surface to breathe every few minutes.

That is not very useful when living in a marine environment, because it means you do not have a very long time to find the food that you need underwater and dive.

So animals who live in marine environments can hold their breath for much longer than we can.

This elephant seal can hold it's breath for 60 minutes, which is really impressive.

I couldn't even hold my breath for one minute.

This gives this elephant seal a whole hour in order to live and do what it needs to do and find its food and swim away from predators underwater.

As well as holding its breath for a really long time it can also dive really deep.

So it can dive up to 2000 metres which is like five houses stacked on top of each other.

The longest ever recorded dive was actually not by this lovely elephant seal, it was by a whale, a Cuvier's beaked whale, and it lasted 137 minutes, which is the world record for the longest diving mammal.

So that's a really impressive adaptation.

I've got some questions for you now, the first one is can you add a label to your original shark picture? So the one you drew originally when we labelled the camouflage to show how sharks breathe underwater, I'm giving you a hint, and then could you answer the question how are marine animals that don't breathe underwater adapted? So if they don't have what they need to breathe underwater, can you write a sentence to explain how they do it instead.

Pause the video and answer these questions for me now please.

Great, let's check our answers.

So for number one, you needed to have drawn some extra gills on your animal and added a label that said gills to extract oxygen from water.

And then for number two, you might have written something like some animals have blow holes, which makes it easier to breathe at the surface and they can hold that breath for a very long time, for example, elephant seals can hold that breath for 60 minutes.

I would like everybody now to pause the video and find some way of improving your answer.

So even if you've got these two things right, is there a way you could improve your answer? Could you include an example? So for example, elephant seals can hold their breath or maybe the whale example that we spoke about.

Everybody now please pause the video and improve your answer.

Great.

That brings us on to our last set of adaptations, which are all about movement.

There are two animals on your screen, a dolphin, so I am including a lot of dolphin examples, dolphins are my favourite animal, and a tiger.

What do you notice about the difference between the tiger and dolphin body parts? So look at the body parts on the dolphin, look at the body parts on the tiger.

What do you notice? What are the differences? Pause the video and have a think for me now.

So some of the main differences are that dolphins don't have arms or legs.

There's lots of other differences, but that's the main one.

They don't have arms or legs.

They don't have hands with individual fingers.

They don't have feet with individual toes.

Instead they have flippers and fins.

So these are their flippers and then that tail is called a tail fin and they've got a fin on their back as well like this, it's what sharks are famous for their shark fin.

There's a reason for this and it's because it helps them to move through the water.

Tigers can actually swim, they swim a bit like humans.

They paddle, but dolphins are much better at swimming.

It's what they're adapted for.

So here is a picture of a hand and the fin of a whale.

We're going to talk about why fins are much better for swimming than hands.

When we swim, we push water.

And by pushing this water back, we propel ourselves forward.

The more water we can push, the faster we can go.

Fins and flippers are better than hands and arms at pushing water because they have more surface area.

So the area of them is bigger.

But also because there's no gaps for the water to get through.

When we push water with our hands, the water goes through our fingers so we can't push as much of it.

Whereas if you have a fin it acts a bit like the paddle on a boat and it means you can push much more water.

There's no gaps for it to get through.

So that's why marine animals have different body parts to us so that they can push more water to propel themselves forward.

Can you just say that sentence with me? I'm going to say it one more time and then you're going to set to help us remember.

Fins help animals to push more water.

Your turn.

This helps to propel them forward.

Your turn.

Great.

Let's think about another part of their bodies.

I've got three marine animals on the board again.

Can you draw on your piece of paper a rough outline of the shape of each of that animal.

So I've done an example for you of the dolphin in orange.

So I ignored its tail and its fins and the little fiddly bits, just the rough shape of its body is kind of like a curve like that.

Can you pause the video and can you draw the rough shape of the sea lion's body and the rough shape of the shark's body please? Pause the video and do that for me now.

Great.

So hopefully you drew something a bit like this.

And we can see that when we trace the outline or we draw the outline of these body shapes they all have roughly the same shape.

The reason for this is because this is a very streamlined shape.

We spoke about this in our keywords, streamlined.

Can you remember what it means? If you can set your screen.

Streamlined means moves easily through water or through air.

So by having their that bodies this shape, it means they can move easily through the water.

You'll notice the shape is all a bit like the shape of an aeroplane, which we spoke about being streamlined as well.

I've got some questions for you.

So again, can you go back to your shark diagram and can you add labels to your original shark picture to show how sharks bodies help them to move underwater? So add a label that explains how it helps to move.

In fact, you probably need to add two labels.

One about it's body shape and the other about what it has instead of arms and legs.

And then question two, could you write a sentence or two sentences explaining why a fin is better than a hand for swimming? See if you can use those keywords, push and propel.

Pause the video and do that for me now, please.

Great.

Let's check your answers.

So these are two labels that you might have added to your shark.

Streamlined body shape, and also fins to push water and help with swimming fast.

And then for question two, you might've written an answer like this.

Fins are better than hands for swimming because they have a bigger area and water cannot get through the gap in between fingers.

And then you go on to explain why this is helpful.

This means fins can push more water and propel you forward faster.

Well done if you've got those correct.

I would like everybody now to pause the video and think about how you can use what's on the screen to make your answer even better.

So even if you wrote the right answer, is there another key word you could include, is there is a little bit more information you can add.

We should always try to improve our work if we can.

Pause the video and have a go at doing that for me now, please.

Fantastic.

Well done, you've worked really hard today.

We've learned all about marine environments and how animals are adapted to move through those environments, to breathe in those environments and to camouflage in those environments.

I hope you're really proud of the work that you've done today.

I definitely I'm proud of how hard you've been working.

If you would like to, then you can show your work to somebody in your house, or you could ask your parents and carers to share photos of your work for you on Twitter.

And if they do that, they can include the hashtag learn with Oak or hashtag O and A science.

I hope you have a fantastic rest of your day and I will see you back here soon for another science lesson.