Adaptation (GCSE Biology)


Uploaded by freeeschool on 04.09.2012

Transcript:
GCSE Biology - Adaptation
Hello! Welcome to a video about Adaptations. We are going to look at the kind of adaptations
that living things have that allow them to compete and to survive. We are going to look
at a couple of examples of animals and also an example of a type of plant, as well.
So it starts off with some plants here; we got examples of some animals and some mice
here. The kinds of things that they need to survive are the kinds of things they need
to compete for. All of these plants are all competing for certain things in their environment
as of the animals, the mice. The kinds of things that plants compete for and these are
the kinds of things that you should be able to know and that you should be able to write
down, are things like light for photosynthesis; they need water especially for photosynthesis;
and they require space which gives them more ability to get the nutrients out of the soil
and of course. They need the nutrients so they compete for nutrients as well.
Animals compete for slightly different things. They compete for food. They compete for territory
and they compete for mates. By mates, we mean by reproduction partners. The other reason
why they do this and why they compete is so that they can reproduce. That goes for plants
and animals and if they can reproduce, the species will survive. The kinds of individuals
within this species that compete the best are the ones that are best adapted and if
they are well adapted, they can compete for the things they need and to get the things
they need and therefore, reproduce and survive.
So letÕs have a look at some examples of living things or animals that are in a cold
environment and I have here a desert fox and I have a whale, specifically a killer whale.
They both live in cold environments and some of the adaptations are as follows:
- The first and the easies one for this desert fox here is that it has white fur or the color
of it is white. The reason for that is for camouflage and camouflage or the white color
will help it to blend into the snowy background and therefore, its prey wonÕt be able to
detect and is therefore, easier for it to catch its prey. ThatÕs one particular advantage;
- The other one is the fact that it actually has a thick layer of fur. While its white
fur is also very thick and the advantage of having thick fur is that it can trap layers
of air and air is a very good insulator. It doesnÕt allow heat to transfer across it
very easily, especially if it kept still. A thick layer of fur which will trap air and
that acts as an insulator and that will reduce heat loss.
- Now another problem with heat loss will come from parts of the body that stick out,
for example: the ears. The adaptation that the desert fox has is it has small ears and
that feature helps to reduce surface area; S.A. stands for surface area. If it has a
less surface area in contact with the air, itÕs going to loss less heat to the environment.
ThatÕs three specific adaptations for this desert fox. HereÕs for the whale:
- One of the features that it has is that it is large. In cold environments, large animals
can conserve heat better than small animals. This is because they have a larger surface
area, so a smaller surface area to volume ratio means that for the size of the ears, it has a low surface area, which
means that it can reduce heat loss, such as the very fact that it is large means that
it can conserve heat better because it got a smaller surface area to volume ratio.
- The other thing that it has is the thick layer of fat and that thick layer of fat is
a great insulator. Remember when you are talking about the adaptations, they often ask you
to explain the adaptation. DonÕt just say that it has a thick layer of fat. You have
to say why that is useful. So a thick layer of fat, which is an insulator so it can reduce
heat loss.
These are couple of examples of adaptations of animals that live cold environments. I
mention size. If we are looking at a hot environment, elephants are quite large. So the fact that
it is large is quite a disadvantage for it because it finds it difficult to lose heat.
This is trying to lose heat because it is potentially -- it is in a hot environment
and it can overheat. One of the adaptation is has is the large ears. Now, again, the
phrase is commonly mentioned in this topic, the large ears give it more surface area.
The surface area is quite important here. The reason why the ears have a large surface
area and why that might be useful is because we do have also have a large blood supply
to those ears. The combination of the warm blood in the ears and a large surface area
is we have more heat loss through radiation. More heat can be radiated away from the body of the elephant through
these large ears which have a large surface area. Sometimes, you might have seen on TV
that the elephants do stand there just flapping those ears which again helps get rid of the
heat from the body of the animal.
The last thing that I want to do is just look at the adaptations of a plant in a hot environment.
This is a desert and the type of plant we have here is a cactus. There are various adaptations
that it has. The first one is these spines here are actually the leaves and they have
a low surface area. Here is our key term, surface area again. So they have a very low
surface area which means there is less surface for the plant to actually lose water from
in this case. This big, thick part is actually the stem. So it has a very thick stem and
that can be used to store water. The last thing that I want to mention here is a large
root system. The reason that is has a large root system is so that it can stretch and
gather water from a large area. Also the root system is very close to the surface of the
soil so that if there is any rain, if there is a tiny amount of rain, it doesnÕt have
to penetrate all the way deep into the soil for the cactus to be able to collect it. It
can collect it almost as soon as it hits the ground because the roots are not only long
but they are very close to the surface of the soil.
There are adaptations or a variety of different living and why they compete in order to survive.
[end of audio Ð 08:18] GCSE Biology - Adaptation
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