>> Good morning, boys and girls.

My name is Mrs.

Lewandoski, and I am a fifth grade teacher at Park Avenue Elementary School in Freehold Borough, New Jersey, where we are known as the Eagles.

Today, you're all going to join me and the honorary Eagles for the day.

First of all, I wanted to take this opportunity to thank you and tell you how proud I am of each and every one of you for being home during this time and doing as much schoolwork as you can and staying on top of your education.

It is so important that you're doing that, and we are all just so super proud of you.

To start off our day at Park Avenue every day, we say a pledge, and I would like you to repeat after me, and then we could all be honorary Eagles for the next hour.

So we start off our morning, we say, "The PAE way.

We never give less than our best.

Be kind.

Work hard.

Have fun.

All right, now that we've said that, we are all honorary Eagles for the day.

Today for science, we're going to focus on what is energy, why do we need it, and how it's transferred between living things.

So, first of all, let's talk about energy.

Energy is what exactly?

We know that we need it, but what is it?

Energy is the ability to do work.

What does that even mean?

Well, let's start off with how we get energy.

Now, we get energy from doing what?

Eating.

Now, how do we get that energy?

Well, it all starts off actually with the sun.

Let's take a look at something I have here.

So I have this plant here.

This was given to me by a friend of mine.

This plant has been sitting on my windowsill.

Now, it was a very small plant when I first got it, but it's grown into this big plant with all of these leaves on it.

Now, what does this plant need to survive?

I'm going to give you a second just to think about that.

Now, if you said that this plant needs air, you're right.

Water, absolutely.

Sunlight, absolutely.

It needs these things to survive.

Now, with this sunlight, these plants start to grow with the right amount of water.

Now, since this plant was on my windowsill, I want to show you what happened, and I want to see if you can draw a conclusion as to why this started happening to my plants.

I'm going to turn it around.

Now, this side of my plant was facing the sun.

You can tell it's nice and green.

It has beautiful color.

The leaves are really high on it.

Let's turn this plant around and look at the other side.

What do you notice right here?

You should have noticed it right away.

What do you see?

Right, this part of the plant is starting to actually discolor a little bit.

Why do you think that is?

This part of the plant was facing away from the sun.

Now, if I didn't rotate my plants enough, this particular stalk most likely did not get enough of what?

Sunlight.

Maybe not enough water since it was on the other side.

Maybe I wasn't watering that side enough, okay?

So it looks like this part of the plant actually needs a lot more sunlight, and it might need some more water.

Let's take a closer look at what this plant does with the energy that it gets from the sun, okay?

So what I'm going to do is I'm going to spin you around a little bit.

And we're gonna take a look over here.

Now, what a plant does with this energy, it turns it.

It takes that sunlight and it turns it into food for itself.

That whole process is called photosynthesis.

It's a really big word.

Say that with me.

Photosynthesis.

One more time.

Photosynthesis.

Excellent.

You're going to notice a lot of different things on this plant, so let's go over a few things really quickly.

First of all, I drew a very simple plant.

My students in my class would tell you I am not the best artist, so I did my best with all my artwork here for you today.

So we have our sun up in the corner and we have our plant, okay?

First, let's start with the first step of photosynthesis.

This is the first thing that happens.

What do you think the very first thing that happens is?

Great, this sun actually gives energy to this plant.

So the energy is absorbed by the chloroplasts in our leaves.

So that energy gets absorbed into the leaves and gives it to the plants.

Chloroplasts are tiny, tiny little structures on the leaves that help the plant go through the process of photosynthesis.

Now, from here... So the sunlight comes into the plant.

So we'll draw some arrows for that sunlight.

Great.

The next thing we have here is carbon dioxide.

Say that with me.

Carbon dioxide.

One more time.

Carbon dioxide.

Excellent.

Carbon dioxide is present in the atmosphere.

What do you think the carbon dioxide does in this process of photosynthesis?

Okay, so carbon dioxide actually enters from the atmosphere through the pores in the leaves.

So carbon dioxide is going to go into the plant.

It's going to come into that plant.

Okay, so we have it absorbing the sunlight.

The carbon dioxide comes into the plant.

Okay, now, what do they do with all this carbon dioxide and sunlight?

What does the plants make?

Do you know?

Well, we know it has to make energy, but how does it make that energy?

Okay, we're actually going to move over to this side of the poster now.

Sugar.

It's also known as glucose in plants.

So the carbon dioxide comes in from the atmosphere into those pores.

The plant starts going through the process of photosynthesis and it makes sugar, okay?

It feeds the plant when that sunlight gets to those chloroplasts.

So the plant starts making sugar.

That's how it starts getting that energy.

So it starts making that sugar or glucose.

Now, what do we do with that sugar?

What does the plant do with it?

Great, we have one step left.

If you looked up here, you would have seen oxygen.

Now, the oxygen is actually released back into the atmosphere, okay?

So the oxygen comes out of the plant.

So the carbon dioxide comes into the plant, the oxygen comes out of the plant, okay?

Why do we need oxygen?

Excellent.

We breathe it from the air.

We breathe that oxygen from the air.

So we need plants.

The plants help to create more oxygen in the air, and this whole process goes over it.

Let's go over the process one more time very quickly to make sure you understand it.

Okay.

So this is photosynthesis.

The plant is going to absorb that sunlight.

That energy is absorbed.

It traps it inside.

That carbon dioxide comes in through the pores on the leaves.

Sugar is start to be made -- started to be made inside the plant.

It starts to make that sugar, and then the plant releases the oxygen into the air.

As it's doing this, the plant is starting to grow and develop, and that's how we get different things that we need.

First of all, we get the oxygen that we need into the air.

And if you eat plants, which I'm sure that you do, you get energy you need from those plants.

What are different types of plants that we eat?

I'll give you a minute.

See if you can think of three.

So if you said anything that kind of grows, if you have a garden at home and you grow different kinds of vegetables, you might have a garden.

You might get your vegetables from your local store or supermarket or farmer's market.

You might grow apples, tomatoes, cucumbers, lettuce, eggplant.

All of these different things are actually produced from plants, and the whole thing is gonna start with the sun.

We need the sun to start this process so that it can begin for us.

Now, the next thing we're going to take a look at is why these animals need energy and how they get it.

Now, we're going to look at the four main reasons why animals need energy to survive, so I'm going to give you a couple seconds.

You can turn and talk to somebody sitting next to you.

If you have paper and pencil nearby, you can jot them down.

You could just think them in your mind if you'd like.

But try to think of those four main reasons why the animals need energy.

So I'll give you a little bit of time to think about that.

Keep up five more seconds.

All right.

One of the first reasons that animals need energy is for growth, okay?

Put this up here.

Once we go over our four reasons, we're going to explain what they all mean.

The next reason, warmth.

The next reason, movement.

And the last reason, body repair.

So now let's go over what all of these mean.

First of all, growth.

What does that mean, growth for an animal?

Well, same thing it means for a human, really.

Is that the animal needs to grow to be able to survive.

They have to develop into the adult animal.

They can't stay a small animal.

They have to develop and get the skills that they need as an adult to survive.

They need to learn specific skills.

What kind of skills would an animal need?

Something like hunting for food, staying safe, survival, all things that an animal would need to know, okay?

Let's talk about warmth.

Why is that important for an animal?

Why is warmth important?

Well, warmth is important because animals need to regulate their body temperature, meaning they have to keep it at an even temperature just like humans.

Now, if you think about it, our body temperature is usually an even 98.6 degrees.

That's right around where we are.

If you're not feeling well and you get sick, usually you get a fever.

Your body tries to combat that fever, to regulate your body temperature, to help you stay well.

Animals have just about the same thing.

They need to regulate that body temperature so that they can survive in their environment.

Think about all the different environments that animals live in.

We have animals that live in the North Pole like polar bears.

We have animals that live in other climates like the desert, and they all have different ways to regulate that body temperature so that they can survive.

Okay, let's talk about the next one, number three, movement.

Why do animals need movement?

That seems like an easy one.

Something to think about.

Why do they need movement?

Well, they need movement because they need to hunt for prey, and they need to hide from prey if they're being targeted, right?

So they need to be able to hunt for their prey so that they can eat to survive, or hunt for food if they only eat plants and they don't eat other animals.

But they also need to know how to hide and how to survive, how to move around, okay?

The last one, number four, body repair, right?

Think about body repair.

What happens if you're outside and you're riding your bike and you fall?

What happens?

Well, if you didn't have on kneepads or anything protecting your skin, you would probably get like a little cut or a scrape on your arm.

Well, your body needs to repair that cut or scrape.

So what it's going to do is it's going to start to make that hard kind of scab that we get on the top.

Same thing happens for animals, right?

If they're injured, they need to heal those wounds.

They need to get their body repaired so that they can resume normal activities, okay?

These are the four main reasons that the animals need the energy.

So all of these ways are ways that they need that energy to survive.

The first one was growth.

The second one was warmth.

Number three was movement.

And number four, body repair.

Now, were you able to think of any of these on your own?

Try and brainstorm other ways that they might be able to use these four ways to survive besides the ones that we discussed.

Okay, now what we're going to talk about now is how animals get the energy.

So we discussed why they need the energy.

Now we're gonna think about how they get that energy.

Okay, so we're going to talk about food chains.

Now, you may or may not have learned about food chains in school, so you might have some background knowledge on this already.

So let's talk about food chains together.

Okay.

What is a food chain?

Okay, a food chain is a way to show the transfer of energy between animals, okay?

What we're gonna do is we're gonna do something that I like to do in my class with my students.

I'm going to show you an example of a food chain.

Then I'm going to give you some animals and have you try to do it at home.

So if you have paper and pencil, you can gather it.

This way you can do that next.

So I'm going to do a sample one for you.

Grab my marker.

Okay.

So we're going to start with what all food chains are going to start with, where all of the energy starts with, what we discussed before -- the?

Sun.

Now, the sun is going to give energy to -- in this example, it gives energy to the grass.

Okay?

That grass is going to give energy to -- in this example -- a grasshopper.

I'm gonna put it down here.

And the grasshopper is going to give energy to a... frog.

The frog will give energy to a... snake.

And the snake will give energy to a hawk.

Now, the way I set up this food chain is important.

You notice what they usually all start with -- the sun.

Okay?

Now, the way your arrow points is the way the energy is being transferred.

So the sun gives the energy to the grass.

So the arrow has to be pointing in the direction that it's going, the way the energy is flowing through the food chain.

The arrows wouldn't be facing the opposite direction, even though that's the way they eat.

For example, the hawk would eat the snake.

The snake eats the frog.

The frog eats the grasshopper.

The grasshopper eats the grass.

And the grass gets energy from the sun.

Okay?

The arrows wouldn't point that way.

That would actually be in the opposite direction.

They need to point in the way that the energy is going to flow through that food chain, okay?

So what we're going to do now is I'm going to give you some examples.

If you have that paper and pen or pencil, crayon, whatever it is you have, I'm going to give you an example, and I want you to try and put that food chain in order in the example that I'm giving you, okay?

So this is in no order.

Use a marker.

Okay, so the first one I want you to try, you're gonna write down... ...is a nut tree.

Next, a fox.

Next, a squirrel.

And the last one.

The sun.

Okay, so just really quickly, I'll hold them up for you one more time if you didn't get them all.

We have a nut tree, fox, squirrel, and the sun.

And what you're going to do is I want you to set it up like this and show me which way the arrows are facing so that you can see the transfer of energy from one thing to the next.

I'm going to give you a couple seconds to set that up.

I'm going to get my tape ready, and we're going to put your example right here on the bottom.

So go ahead and take your time.

All right.

So what does all of the food chain -- what do all of the food chains start with?

It should start with the... sun.

The sun should have been the first one that we've put down.

Okay, the sun.

Now remember, your arrow points away from the sun because the sun gives energy to -- What did you put next?

The nut tree.

Excellent.

Remember your arrow.

Now, the nut tree is going to give energy to... he squirrel, right?

Okay, don't forget your arrow.

And just because I'm out of room, this is going to go on the next line, but the last one you should have is fox, and the fox would be the last one in this food chain, and I'll just draw a little arrow down here, too.

Make sure you can see that.

Gives energy to the fox, okay?

So here is our food chain completely set up.

We have the sun gives energy to the nut tree, which gives energy to the squirrel, which gives energy to the fox.

Okay, so we have our two basic food chains.

I want you to think about different animals that are in your neighborhood.

What are some animals around your neighborhood?

What could be those possible food chains?

I'm going to give you a couple seconds just to think about that because there are food chains out there in our environment.

Go ahead and think about that for a second.

Okay, another thing we're going to discuss are food webs.

Okay?

Now, in order to really understand food webs, we have to do a food chain together to see that transfer of energy.

A couple of vocabulary words we should know before we go into our food web.

The first one is producer.

Say that word -- producer.

Very good.

A producer is anything that's going to make its own energy.

For example, what did we discuss at the beginning of our lesson?

The plant, very good.

So this nut tree here or the grass in this food chain would be our producer.

Anything that eats plants is going to be called a consumer.

Anything that eats plants or animals, I really should say, is called a consumer.

So, for example, in this food chain right here, what would be the consumers.

Is the sun a consumer?

No.

Would the grass be a consumer?

No, the grass is a producer.

It makes its own energy.

The grasshopper?

Yes, it is a consumer.

The frog?

Yes, it is a consumer.

The snake?

Yes, a consumer.

The hawk?

Yes, a consumer.

So down here on the one that we made together, we have the nut tree is the producer.

Our squirrel would be the consumer, and the fox would also be a consumer.

Now, in the food chain that we meet together, there is a difference in the consumers between the squirrel and the fox.

The squirrel is actually called a primary consumer, okay?

What does the word primary mean?

Tying in some vocab for you.

What does the word primary mean?

Primary means first.

So the squirrel is actually our first consumer, meaning it's the first animal to start consuming that food.

So the squirrel would be our primary consumer, which makes the fox -- it wouldn't be primary.

It would be secondary, meaning it comes next.

So it would be our secondary consumer.

Okay, let's go over some of the vocabulary that we discussed in the last 15 minutes, because it was a lot of different words that I just gave you.

First of all, we went over food chains, which show the transfer of energy from one thing to another.

In the food chain that I gave you, we had the sun giving energy to the grass, which gave energy to the grasshopper, which gave energy to the frog, which gave energy to the snake, and the snake gave energy to the hawk.

So you can see that kind of transfer of energy.

We noted how important those arrows are.

The arrows have to show the direction that the energy is going.

So the sun should be pointing towards that grass.

We also talked about producers and consumers.

A producer is something that's going to make its own energy.

So, for example, in the one we did down here, the nut tree would be the producer.

It makes its own energy with the help of the sun.

In the larger food chain we had, this grass is going to get its energy from the sun.

It makes its own, which makes it a producer, right.

The other word we discussed is consumer, right?

Those would be your animals or living things that eat other living things to survive.

This squirrel eats the nut tree.

This fox eats the squirrel, okay?

A couple other words that are important to know... Okay, is we have herbivore.

Okay?

A herbivore would be a different type of -- would be a specific type of animal that eats only plants to survive.

So a herbivore eats only plants to survive.

So this squirrel only eats plants.

It is not going to eat other animals to survive.

Another type of animal or living thing would be a carnivore.

Okay?

A carnivore eats only animals to survive, so it does not eat plants.

It only eats meat.

So if we were going to look at this snake, the snake would only eat the other living thing, so it would only eat that frog.

That would make it a carnivore.

It would not eat plants, okay?

Same thing with a hawk, right?

The hawk is going to eat that snake or other tiny little birds, which would mean it would only eat meat, which makes it a carnivore.

Okay, so those are just the different types of living things that you're going to see out there in our environment, okay?

So we'll say the words one more time.

I'm going to say the words.

If you could repeat the words, that would be great.

So we have just a lot of vocab here.

Food chain, producer, primary consumer, secondary consumer, herbivore, and carnivore.

Now, if you wanted to take a minute and kind of write down these words, this way, you can remember them.

Sometimes if you write down words say on index cards with a marker, pencil, crayon, whatever it is that you have -- if you don't have index cards, you could always just use paper.

It makes it a little bit easier to remember.

So you can definitely come up with different food chains that live in your neighborhood, in your area, in your environment.

Take a second, just go over this.

Make sure that you understand it.

The next thing we're going to do together is we're going to talk about what happens when different food chains intertwine with one another.

So, many food chains make up something really big called a food web.

Okay, boys and girls, if you noticed, I kind of changed my scenery a little bit.

So when you're getting your materials together, just make sure that you have paper, pencil, or something to write with.

If you have just a regular-sized paper, that's fine.

Okay, so I'm just giving you some time to get some paper, some materials together.

While you're doing that, I'm going to go over what we're going to do together.

Okay, so this right here is a food web.

What we're going to do together right now is we're going to identify all of the food chains inside this food web.

What a food web really shows you is how many food chains can exist within one environment.

So that's what we're going to look at today.

So just give yourself another maybe 10, 15 seconds.

Get those materials together.

As soon as we're done going over this, I'm going to give you some animals to write down, and then you're going to try to put the food web together yourself at home.

All right, so you should have all your stuff together now.

Let's take a look at what I have here.

So if you can see, I put all of our animals right here on this chart.

So we have a mix of different animals and plants.

Let's look down here.

First let's read everything.

We have corn, plant, lavender, mangoes, fruit fly, butterfly, grasshopper, frog, rats, wolf, python.

Over here we have eagle, thrush, dragonfly.

I believe I said fruit fly and mangoes over here.

So just like with a food chain, we have to draw the arrows inside the food web to show the transfer of energy.

So let's take a look over here.

Let's start down here with the corn, okay?

The corn is going to get eaten by the grasshopper.

So I'm going to draw my arrow there, okay?

The grasshopper is going to get eaten by... the frog.

Okay?

It will also get eaten by a rat.

And the rat will give its energy to the python.

So we've started basically here a food chain.

If you notice, the grasshopper has two arrows coming off of it because it gives energy not only to the rat, but also to the frog.

Okay, let's come back to the bottom and we'll work our way back up again, and then I'll show you how they really intertwine with one another.

So here down here, we have a plant, should really be some type of flowering plant, so that kind of flowering plant would give its energy to the butterfly.

Okay, the butterfly would give energy to the frog.

And this frog also gives energy to the python.

So already within this food chain -- within this food web, excuse me, we've identified two, possibly three different food chains.

So let's keep going.

Let's come back down to the bottom with the lavender.

So the lavender could give energy to the butterfly.

The lavender gives energy to the butterfly, excuse me, then we'll switch over to the mangoes.

The mango gives energy to the fruit fly.

Okay, this fruit fly gives energy to the dragonfly, to the thrush.

Thrush is a type of bird.

Fruit fly also gives energy to the frog.

Okay, now let's move up here to the dragonfly.

The dragonfly gives energy to the frog, as well.

Okay, this thrush gives energy to the eagle.

The frog is actually going to give energy to the eagle.

And the python gives energy to the eagle, as well.

This rat gives energy to the wolf, also gives energy to that eagle.

So if we take a look at this, if you look at all of these arrows here -- I'll move you in a little bit closer -- you can see how they really are all intertwined with one another.

Now, within this food web, we also have our producers that we talked about earlier in our segment.

We have our primary consumers, and we have our secondary consumers.

I want you to take a second look at this chart and tell me where we could find our producers, our primary consumers, and secondary consumers.

So take a second here.

I'm going to grab my index cards so that we can label them.

So take a second, see if you can identify any of those for me.

All right, hopefully we're able to identify some of those from what we learned earlier.

So let's start at our producers.

Where would the producers be inside a food web?

Where would you find your producers?

They would be down at the bottom, right?

Our plants give energy to everything else.

Kind of like what we discussed at the beginning.

All of these down here would be producers.

They would be your first layer in any food web.

Now remember, what would be right here if we really wanted to that gives energy to those plants and those producers?

The sun, right.

The sun would be down here, which would give all of the energy right here to these producers.

Where would your primary consumers be?

Good, your primary consumers would be the next level right on top of your producers.

So your primary consumers would be right in here.

You would have your grasshopper would be the primary consumer.

The butterfly is also a primary consumer.

The fruit fly would also be a primary consumer.

Now, what about a secondary consumer?

Good, that would be your next layer.

So your secondary consumers would be right kind of in the middle, okay?

For this specific food web, your secondary consumer would be the rat, the frog, the dragonfly.

Those would all be secondary consumers.

Depending on how large the food web is, you could also do, you know, your third consumers and so on and so forth up your food web.

You guys did an excellent job doing this, so now what I'm gonna do is I'm going to give you some examples to write down.

So this is where your paper and pen or pencil, whatever you have, comes in handy.

Let me take this down.

So I'm going to give you some examples of what I want you to write down.

Okay, if you just have regular paper, you can actually just cut it right up the middle.

Cut it in half and then cut it in half again and you'll get smaller cards.

Looks somewhat like this.

Okay, so I'm going to show you what I want you to write down.

This way you can get those written down and then you can try to set up your food web.

Okay, so the first one to write down -- rabbit.

The next one -- birds.

Next -- mouse.

Next -- carrot.

Whoops.

Carrot.

Okay.

Grains.

Grasshopper.

Fox.

Owl.

And grass.

Okay, they were not in any type of order, so if you have all those written down, what I'm gonna do is I'm gonna give you some time.

Use the floor in front of you, use the table, whatever space that you have wherever you are right now and try to organize your cards so that they set up like a food web.

If you have extra paper, you can do arrows so that you could see that transfer of energy within the food web.

If you don't, if you could just lay them on the floor the best that you can, and what we're gonna do is I'm going to put it together for you right here.

I'm going to give you a minute, maybe a little bit less than a minute, and have you set that up.

So I'll give you some time while I set up my cards.

Okay, remember what would be at the bottom?

Anything that produces energy by itself.

Those would be your plants.

Next will kind of be smaller animals.

So just keep that in mind when you're setting up the cards on the floor.

All right, so I'm going to get started.

Hopefully you were able to get some of your cards in order on the floor.

So one of our first things that should be at the bottom, of course, would be grass.

Okay.

Maybe I should move that down so we have some more space.

Okay, so our grass should be down there.

Were there any other producers that you noticed?

Another one should be carrot.

Very good.

We'll put this one over here.

And then there was actually one more producer in this mix.

Should have been the grains.

We'll put them over here.

Okay, so, so far, we have our three producers are in our food web.

We have carrot, grass, and grains.

All right, out of the animals that I gave you, what do you think would eat that carrot?

Rabbit.

Excellent, boys and girls.

We're going to put this here.

I'm going to save my arrows for the end.

Okay, now, if I'm thinking to myself -- if I look at these animals and I want to continue maybe with just that food chain, I'm going to think what would eat that rabbit?

So it would be a fox.

So this would come up right here on top of that rabbit.

Okay, if yours is set up similar to this, that's fine.

Okay, and then we come back down here to the bottom, and I know from my cards that a grasshopper is going to eat grass.

Gonna put that right in here.

Okay, next, if I think about what eats a grasshopper, I know that a mouse would eat a grasshopper.

Put the mouse right here.

Okay, you should have two left, birds and owl.

Okay.

I know that birds also eat grasshoppers, so I'm gonna kind of put these birds right here.

And the owl, being one of the larger animals in this food web, is going to go to the top because an owl's going to eat a couple things in here.

Okay.

So we're going to put our owl kind of at the top.

All right, now for our arrows.

So, if we start down here with the carrot, we know that the carrot is going to give energy up to that rabbit, okay?

I'm gonna pull you in a little bit closer so you can see.

The rabbit is going to give energy up to that fox.

Okay?

The grass is going to give energy to the grasshopper.

But it's also going to give energy to the rabbit.

Okay.

This grasshopper is going to give energy to the birds.

These birds are actually going to give energy to the fox over here.

Okay, the grasshopper's also gonna give energy to the mouse.

This mouse is going to give energy to the owl.

Okay.

We come over here to our grains, the grains also giving energy to the mouse.

Okay?

So looking at this food web, we see that all of these things are very much intertwined.

Now, again, if we were going to come in here and label our producers, primary consumers, and secondary consumers, we could come in here and do that, so I'm gonna give you a couple more seconds.

I want you to try to identify them in here, and then we're gonna label them with our cards.

All right, so you should remember that your producers are going to be down here at the bottom.

So in this food web, the carrot would be your producer, the grass would be your producer, and grains would also be a producer.

Remember, producers get their energy from the sun.

Now, where would your primary consumers be?

So the primary consumers are the ones that eat those producers.

Very good, they're going to be the next level up.

So your primary consumers would be the rabbit.

It would be the grasshopper.

And another primary consumer would be the mouse if it was eating these grains.

If you're going in that food chain, the mouse would be primary.

If you were looking at a different food chain, the grass to the grasshopper to the mouse, it would be a secondary consumer.

And where would our secondary consumer be?

Very good, the secondary consumer would be at the top.

Okay, so the fox would be secondary right here.

The mouse would be secondary here.

And depending on the food chain, the owl would be the secondary here.

Now, all of these animals make up a specific ecosystem.

Okay, within their ecosystems... ...this would be kind of balanced.

If something comes in, it can actually throw off the balance of an ecosystem and of this food web.

So if something becomes overgrown, like if the carrots are overgrown or if there are too many rabbits, it can actually throw off the dynamics of a food web, a food chain, and it really could throw off the dynamics of an entire ecosystem.

So keeping everything in balance is actually very important.

What I'm gonna do is I'm going to pause here.

I'm going to actually show you a small video, and the video actually is going to show you what happens when wolves were reintroduced to an ecosystem.

So they were brought back into Yellowstone National Park, and it's just this amazing video and it's going to show you a different kind of look at an ecosystem and how it can positively affect it.

So let's take a look at that video really quickly.

[ Wolves howling ] ♪♪ ♪♪ >> One of the most exciting scientific findings of the past half century has been the discovery of widespread trophic cascades.

A trophic Cascade is an ecological process which starts at the top of the food chain and tumbles all the way down to the bottom.

And the classic example is what happened in the Yellowstone National Park in the United States when wolves were reintroduced in 1995.

Now, we we all know that wolves kill various species of animals, but perhaps were slightly less aware that they give life to many others.

Before the wolves turned up, they'd been absent for 70 years.

The numbers of deer, because there was nothing to hunt them, had built up and built up in the Yellowstone Park, and despite efforts by humans to control them, they'd managed to reduce much of the vegetation there to almost nothing.

They just grazed it away.

But as soon as the wolves arrived, even though they were few in number, they started to have the most remarkable effects.

First, of course, they killed some of the deer, but that wasn't the major thing.

Much more significantly, they radically changed the behavior of the deer.

The deer started avoiding certain parts of the park, the places where they could be trapped most easily, particularly the valleys and the gorges.

And immediately, those places started to regenerate.

In some areas, the height of the trees quintupled in just six years.

Bare valley sides quickly became forests of Aspen and willow and cottonwood.

And as soon as that happened, the birds started moving in.

The number of songbirds and migratory birds started to increase greatly.

The number of beavers started to increase because beavers like to eat the trees.

And beavers, like wolves, are ecosystem engineers.

They create niches for other species.

And the dams they built in the rivers provided habitats for otters and muskrats and ducks and fish and reptiles and amphibians.

The wolves killed coyotes, and as a result of that, the number of rabbits and mice began to rise, which meant more hawks, more weasels, more foxes, more badgers.

Ravens and bald eagles came down to feed on the carrion that the wolves had left.

Bears fed in it, too, and their population began to rise, as well, partly also because there were more berries growing on the regenerating shrubs.

And the bears reinforced the impact of the wolves by killing some of the calves of the deer.

But here's where it gets really interesting.

The wolves changed the behavior of the rivers.

They began to meander less.

There is less erosion, the channels narrowed, more pools formed, more riffle sections, all of which were great for wildlife habitats.

The rivers changed in response to the wolves.

And the reason was that the regenerating forests stabilized the banks so that they collapsed less often so that the rivers became more fixed in their course.

Similarly, by driving the deer out of some places and the vegetation recovering on the valley sides, there is a soil erosion because the vegetation stabilized that, as well.

So the wolves, small in number, transform not just the ecosystem of the Yellowstone National Park, this huge area of land, but also its physical geography.

♪♪ ♪♪ [ Wolves howling ] ♪♪ >> I hope you enjoyed that video that talks about the wolves in Yellowstone National Park and how the wolves can help to positively affect Yellowstone National Park.

Remember that when an animal is introduced into an ecosystem or a food web or food chain, it could have positive effects, but it could also have negative effects.

That can be something that you think about after this lesson.

If an animal was introduced to an ecosystem, how could it negatively affect that ecosystem instead of positively, as it did with the wolf video?

What we're going to do right now is we're going to take the last five minutes of our lesson and we're going to review everything that we've done together so far today.

We have done a lot of learning within these last 60 minutes.

So it's going to be our job to try to review this, to help you retain that information the best that you can.

First of all, let's go over photosynthesis.

Remember way back at the beginning of our lesson, I showed you my plant and what could happen if a plant does not get enough sunlight and water.

If you remember, the back of the plant was brown.

And I learned my lesson.

I have to rotate that plant so that it gets enough sunlight on my windowsill.

Let's go over photosynthesis and the important steps that it takes.

Your first step here is sunlight, okay?

That sunlight is absorbed.

That energy gets absorbed into that plant, into the leaves, and the carbon dioxide is going to enter that plant, as well.

Together, it's going to produce sugar, or glucose, within that plant, okay?

That sugar with that sunlight is going to produce this plant and help it to grow.

The plant is going to grow and release oxygen into the atmosphere.

Why do we need oxygen released into the atmosphere?

Well, first of all, we breathe it.

Second of all, those plants help us to survive.

We eat plants, and the animals eat the plants.

So we need photosynthesis.

We need that sun to start this process of photosynthesis.

Without the sun starting the process of photosynthesis, our plants wouldn't be able to grow and give us the nutrients that we need to grow, the animals, as well.

Before we flip to the next poster, if you remember, we went over the four reasons why animals need energy.

Can you think of them?

Okay, the poster got a little ripped there.

All right, so why do the animals need the energy?

Four main reasons.

The first one we spoke about was growth, right?

They have to grow into that kind of adult animal.

Warmth to regulate their body temperature depending on the environment that they live in.

Remember, we discussed polar bears or an animal that might live in the Sahara or the desert.

The third reason was movement, okay, so that they could hunt for prey or hide for prey.

And our last reason was body repair.

Remember, if their bodies get injured, they're going to have to be able to heal themselves within that environment.

The last thing we discussed were food chains and food webs.

So within this food web, we have multiple food chains, okay?

Let's just identify one food chain within this food web.

We have corn gives energy to the grasshopper, gives energy to the frog, gives energy to the python, which gives energy to the eagle.

Remember, those arrows are facing the direction where that energy is going so that you can kind of see that energy transfer.

There are several food chains within this food web.

The last thing we're gonna do is go over some of those important vocabulary words that we learned here today.

So let's look at these vocabulary.

I'm going to say the word, and then if you could just repeat the word out loud, that would be great.

This way you remember it.

Okay, photosynthesis.

Chloroplasts.

Herbivore.

Carnivore.

Food chain.

Producer.

Energy.

Consumer.

Food web.

We'll do that one more time.

Photosynthesis.

Chloroplasts.

Herbivore.

Carnivore.. Food chain.

Producer.

Energy.

Consumer.

Food web.

Okay, boys and girls, I just wanted to thank you so much for joining this lesson today, and I hope that you had fun.

I hope that you learned something.

Again, I'm so proud of you for doing all of your work at home.

From my home to yours, stay safe and be well.

Bye.