Lesson video

Hello, Mr. Jarvis here for today's lesson, and today we're looking at conserving biodiversity.

During today's lesson, you're going to be able to describe a number of ways in which humans are impacting on biodiversity.

There are five keywords to today's lesson.

They are biodiversity, conservation, DNA, gene pool, and gene bank.

The definitions of these words are coming up on the screen now.

You might want to pause the video at this point just so that you can have a read through them, but we will be going through them in detail as we go through the lesson.

Today's lesson is broken down into three parts.

First of all, we're going to look at what biodiversity is, then we're gonna move on to talk about the importance of genetic information, and finally, we're going to wrap everything up together to talk about how scientists are conserving species.

So if you're ready, let's get started with our first section talking all about what biodiversity is.

So biodiversity is the range of different living organisms that live in a place.

The word biodiversity can be broken down into two parts.

First of all, bio.

Bio relates to living things, and diversity is having many different things in one place.

So biodiversity is that range of living things that live in one place.

The higher the number of different organisms that live in a place, the greater the place's biodiversity.

We can measure biodiversity in a habitat by counting the different types of organisms, or species, that live there, and we can use a number of different sampling techniques to determine the different organisms that live in habitats.

Different techniques include quadrats, nets, pitfall traps, and pooters.

Have a think, what different habitats and types of organisms would you use each method for? I'll pause for a few seconds to give you a chance to think and then just talk through some of the things that you might have thought of.

So a quadrat is really useful for surveying plants and slow-moving animals, things like snails, or on a rocky shore, things that are attached to the rocks like limpets or barnacles.

Nets are used for a variety of different organisms. You can use a net to sample aquatic life in rivers and ponds, but you can also use nets to catch small invertebrates in long grass.

Pitfall traps are particularly good at catching ground-dwelling organisms, such as beetles.

And pooters are for small insects that can be sucked up through a little tube from things like leaves.

So, hope you got some of those.

Some habitats contain more species and so have greater biodiversity than others.

An arctic habitat don't have very high biodiversity, and that's because the habitat is a really harsh environment and very few species can live there.

On the other side of the coin, a coral reef habitat has a high biodiversity, and that's because coral reefs contain lots of food, shelter, and places for many different species to reproduce.

So let's do a check.

Which of the following best describes biodiversity? Is it A, the variety of species that live in a place; is it B, the number of individuals of a species; is it C, the variety of species and habitats in the world; or D, the variety and differences within a single species? I'll pause for five seconds and then we'll check your answer.

And the correct answer is A.

Biodiversity is the variety of species that lives in a place.

Well done if you got that.

So let's do a practise task.

True or false, a tropical rainforest has high biodiversity.

When you've decided whether that's true or false, I want you to provide some evidence to support your answer by listing different organisms that might be found in a tropical rainforest.

You can use the image to help you.

If you want to, you could even do a little bit of research.

But you'll need to pause the video, decide what your answer is, and provide some evidence.

And when you're ready, press play and we'll check your answer.

So a tropical rainforest has high biodiversity.

Is that true or false? Well, the answer is true.

You needed to provide some additional evidence to support your answer by listing some different organisms that you might find in a tropical rainforest.

Here's some examples that you might have listed.

So there's lots of different plant species, trees, ferns, and mosses, and you can see a lot of those in the picture on the slide.

There are lots of animals that also live in rainforests, and they include monkeys, gorillas, jaguars, birds such as parrots and toucans, frogs and other amphibians, snakes and other reptiles.

There's huge numbers of different species of invertebrates and many, many, many other organisms that you could have listed.

So the tropical rainforest has a very high biodiversity.

Well done if you got that answer and if you got a long list of organisms that you might find there.

That brings us to the second part of today's lesson, which is all about the importance of genetic information.

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

Conservation is the process of protecting biodiversity and the environment.

High biodiversity maintains healthy habitats, so conservation helps to keep habitats healthy.

Conservation has many benefits for humans.

Some of these benefits include maintaining our future food supply and that new organisms that we might find may be discovered, which help to provide us with medicines.

But another really important and often overlooked aspect of conservation and keeping habitats healthy is the mental wellbeing that nature provides us with.

Everybody enjoys walking in the countryside and it helps us to mentally stay healthy.

Most habitats support stable numbers of species.

There are natural variations in numbers in all habitats, but humans can impact the numbers of species in a particular habitat, and they can do that in many, many different ways.

Some of the main ways are climate change, deforestation, using land to build houses and for harvesting materials, pollution and waste, and overfishing.

Here's two examples there in pictorial form.

We've got some deforestation and some quarrying for materials that are used to build.

Here's a check.

Conservation is important for which two of the following reasons? A, humans need a future food supply; B, conserving organisms maintains biodiversity which keeps habitats healthy; or C, it helps humans to increase land use for agriculture? I'll pause for five seconds so that you can choose your answer and then we'll move on and check to see whether you were right.

So the correct answer here is A and B.

Conservation is important because humans need to guarantee a future food supply and also that conserving organisms maintains biodiversity which keeps habitats healthy.

Well done if you got those.

So when habitats change, organisms may not have the features that they need to survive.

We call those features that they need to survive adaptations.

Here's an example.

Sea ice provides polar bears with the food, shelter, and place to reproduce that they need.

However, with climate change, many of that sea ice is starting to melt and break up, and the reducing sea ice means that polar bears are not as well adapted to the environment as they were.

Characteristics including adaptations of organisms are largely controlled by genes, and genes are units of genetic information which are inherited when organisms reproduce.

Genes are found in the nucleus of a cell.

Here we've got a picture of an animal cell and you can see that the nucleus has been labelled.

Genes are made up of a chemical, and that chemical is called DNA, or deoxyribonucleic acid.

You can see why we abbreviate it to DNA.

There's a picture of the structure of DNA on the right-hand side of the screen.

Genes, the units of genetic information, are responsible for variation between individuals of the same species.

So here we've got some variation in some pumpkins on the left-hand side and giraffes on the right-hand side.

It's probably quite clear what the variation in the pumpkins are, but it's probably not as clear some of the variations in the giraffe.

What variations or differences can you spot? I'll pause for a few seconds and then see what you've come up with.

So in terms of the pumpkin, it's fairly obvious there's variation in colour, there's variation of size, in some cases there's different colour patterns on the pumpkins themselves.

In terms of the giraffes on the right-hand side of the picture, we've got variation in height, and if you look really closely, you can see there are variations in the patterns and the markings that those individuals have.

You may have spotted others.

Well done if you did.

So let's do another check.

Characteristics, including adaptations, of organisms are largely controlled by what? Is it A, genes, B, variation, or C, gene banks? I'll give you five seconds and then we'll check your answer.

The correct answer is A, genes.

The genes control the characteristics of organisms. Well done if you got that.

Many differences are caused by individuals having different genes because of small differences in DNA, and those small differences sometimes give organisms an advantage if the habitat changes, and that means that the organism is more likely to survive and pass on the advantage to its offspring.

So here's another question.

Which wallaby in the picture is most likely to survive and reproduce? Again, I'll pause so that you can have a think and then we'll go through the answer.

So the organism there in the picture, the wallaby that's most likely to survive is the one that has the natural colour.

We have what's called an albino wallaby on the the left-hand side of the picture, the white one, and that means that it's going to be really easily spotted.

It won't be camouflaged, so it won't have the adaptation that it needs to be able to survive.

It won't survive because it'll be easily spotted by predators.

It's most likely that it won't be able to reproduce and pass on its features, its characteristics to its offspring.

Well done if you got any of those points while you were thinking.

The range of DNA, or genes, that's found in a species is called the gene pool, and the larger the gene pool, the range of DNA or the range of genes that's found in a species, the more likely it's going to be able to adapt to changes in the habitat.

And as populations of endangered species get smaller, their gene pool gets smaller too.

So small populations of endangered species are less likely to adapt to habitat changes and they are more likely to face extinction.

Here's an example of an organism that has become extinct within the last 100 years.

The Tasmanian tiger became extinct in about 1926 in the wild and 1936 in zoos, and one of the reasons why it became extinct was because there wasn't a big enough gene pool for it to be able to adapt to its habitat which had been changed by humans.

Here's another check.

What does the gene pool of a population represent? Is it A, the number of species that are found within the population; B, the genetic variation of individuals within the population; or C, the number of individuals within the population? Again, I'll pause and give you a chance to think and then we'll check your answer.

The correct answer is B.

The genetic variation of individuals within the population is what the gene pool of a population represents.

Well done if you got that.

That brings us to our second practise task.

I'd like you to write a short paragraph to explain why elephants, an endangered species, might find it difficult to adapt to their changing habitat.

You'll need to pause the video at this point, have a think, write down your answer, and then press play and we'll check to see how well you did.

Good luck! So I asked you to write a short paragraph to explain why elephants, an endangered species, might find it difficult to adapt to their changing habitat.

Some of the answers that you might have included: as the population size decreases, the gene pool decreases too, and that means that there's less variation in the population.

That in turn means that the population may be less adapted to survive in a changing habitat.

And it takes a long time for elephants to reproduce, which means it takes a long time for genetic information to pass to their offspring.

Well done if you got all or any of those answers.

That brings us to the final part of today's lesson, which is all about how scientists are conserving species.

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

When scientists work in conservation, they do two things.

First of all, they protect the habitats so that organisms have the food, shelter, and places to reproduce that they need.

And one way of doing that is through protecting areas of land as nature reserves.

The second way is by maintaining the gene pool, or what we call the genetic diversity, and this helps organisms to adapt to any changes in habitat in the future.

So although the population of fruit bats in the tree in the diagram all look very similar, they all have very slight genetic differences or variation.

One way that scientists have been helping to conserve species is through preserving habitats, and this often involves protecting land completely, and that means keeping other organisms, including humans, out.

It can also mean that artificial nesting sites are provided if they're needed to help that organism to breed and reproduce.

The otter is one success story.

Scientists have been helping to preserve habitats of the otter, and that's helping to increase the numbers of otters that are found within the UK.

Providing new habitats is another way of conserving species, and this can happen on a really small scale, for example, in a garden or your local park.

Conservation can take place there if organisms are provided with things like bird and bat boxes to provide shelter and breeding places, ponds to help provide drinking water, long grass to provide seeds and shelter, wildflower beds to help provide nectar and pollen for insects, and log piles to provide shelter and breeding places for beetles and hedgehogs.

You can see some examples of this on the right-hand side of the screen.

Let's do a check.

Conserving habitats is important.

This is because habitats provide organisms with, A, food, shelter, and a place to reproduce; B, food and water; or C, food, shelter, and places to exercise.

I'll pause for five seconds and then we'll check your answer.

The correct answer is A, food, shelter, and a place to reproduce are the things that habitats provide organisms with.

Well done if you got that.

Here's another.

Which of the following are ways to conserve biodiversity? Is it A, protecting land completely, keeping other organisms, including humans out; B, providing artificial nesting sites; or C, cutting down trees to create more space? Again, I'll give you five seconds to think of your answer and then we'll check.

So the correct answer here is A and B.

Protecting land completely and providing artificial nesting sites are both ways that can help to preserve biodiversity.

Species can also be conserved in zoos.

Humans can support conservation through breeding programmes in zoos.

And when we visit zoos, entrance money often goes to support conservation activities.

Some people think that zoos are good for animals.

They say things like zoos help educate us about conservation, they help conserve endangered species, or that people enjoy visiting zoos and entry fees are spent on animals and conservation.

Other people are less positive about zoos.

They think that organisms suffer in zoos as they are living in unusual places.

They say things like cages may be small and animals get bored, animals may not have mates for breeding, and animals may not live like they do in the wild.

What do you think about zoos? So zoo conservation programmes work best when they work out how to breed organisms so that the population size of endangered species can be increased, and also they ensure that the breeding programmes are planned to involve as many individuals as possible because we want to maintain that genetic variation.

Work to help conserve the natural habitats of an organism is also really important so that those organisms that are bred in zoos potentially can be then released back into the wild.

And the giant panda is one example of a species that has been successfully bred into zoos and released back into the wild.

As populations of individual species reduce, there's also a reduction in the genetic diversity of a species, and that means that a species may be less able to adapt to changing conditions.

Humans try to maintain biodiversity through the conservation of genetic material for future use in things called gene banks.

And gene banks include collections of seeds or stores of plants and animal cells, and the aim of these is to preserve genetic diversity.

Humans can help the conservation of plants by storing seeds in seed banks, and seed banks are one example of a gene bank.

The Svalbard Global Seed Vault, which is located between Norway and the North Pole, contains over one million seeds from across the world.

The temperature here is really cold, and that helps to preserve the seeds.

Another form of gene bank involves storing embryos, eggs, and sperm from different organisms at very low temperatures in liquid nitrogen, and that's what we call a cryobank.

The idea is that those eggs, sperm, and embryos can then be thawed out in the future to help with breeding programmes and help with genetic diversity.

So let's do a check.

Stores of seeds and embryos to help conserve genetic diversity are called, A, genes, B, gene pools or C, gene banks? I'll pause for five seconds and then we'll check your answer.

And the correct answer is C, gene banks.

Let's move on to our last task of this unit.

Mediterranean brown trout are one of the most endangered freshwater fish in Europe.

Eggs and sperm of the fish have been stored in a cryobank, which is a form of gene bank.

I'd like you to write a paragraph to explain how using a cryobank to store eggs and sperm is helpful in conserving this species.

You'll need to pause the video at this point, write down your paragraph, and then when you're ready, press play and we'll check your answer.

Good luck.

I asked you to write a paragraph to explain how using a cryobank to store eggs and sperm is helpful in conserving the species.

Your answer might have included that pewters are used to store embryos, eggs, and sperm at very low temperatures, and it's one example of what we call a gene bank.

Gene banks are the stores of genetic material to help maintain biodiversity.

The stores of genetic material can be used in the future to help conserve genetic diversity, and this means that in the future, it may be possible to increase the variation through breeding programmes to help the Mediterranean brown trout survive in their habitat.

Well done if you got any or all of those points in your answer.

That brings us to the summary of today's lesson.

Today we've seen that biodiversity is the number of different species that live in a particular place, and when habitats change, organisms have to adapt to be able to survive.

Characteristics of individual organisms are largely determined by genes, and the genes are found in the nucleus of a cell.

Genes are made up of a chemical called DNA, or deoxyribonucleic acid.

The gene pool of a species determines how much variation or difference there is in a population.

The larger the gene pool, the more likely a species will be able to respond quickly to changes in their habitat.

Conservation preserves and protects organisms and their habitats, and humans help to conserve genetic diversity through seed banks and other forms of gene banks.

Thanks for your hard work during today's lesson.

It's been great learning with you as always, and I look forward to seeing you all again soon.

Take care for now.

Bye-bye.