Download Australian environments - NSW Department of Education

Science
Stage 4
NEW SOUTH WALES
D E PA R T M E N T
OF EDUCATION
AND TRAINING
Australian
environments
Set 3: Another look at organisms
Number: 40631
Title: Australian Environments
This publication is copyright New South Wales Department of Education and Training (DET), however it may contain
material from other sources which is not owned by DET. We would like to acknowledge the following people and
organisations whose material has been used:
Extracts from Science Syllabus Years 7-10 @ Board of Studies, NSW 2003
Photograph © Tom Brown
Photographs © Jane West
Photograph © Julie Haeusler
Introduction pp vii-x
Set 1 p 3
Set 1 p 18, Set 2
p 9, Set 5 p 5
Set 1 p 36
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CLI Project Team acknowledgement:
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Editor:
Illustrators:
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Jane West
Tom Brown, Barbara Gurney and Rhonda Caddy
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© State of New South Wales, Department of Education and Training 2005.
i
Australian environments
Here are the names of the lessons in this unit.
Set 1
☞
Who cares?
Lesson 1
Lesson 2
Lesson 3
Lesson 4
Lesson 5
Do you care?
Who is interested in environments?
Environmental jobs
Looking at Australian environments
Describing ecosystems
Set 2
A closer look at relationships
Lesson 6
Another look at living things
Lesson 7
Who eats what?
Lesson 8
Decomposers
Lesson 9
Food chains
Lesson 10
Food webs
Set 3
Another look at organisms
Lessons 11 and 12
Adaptations
Lessons 13 and 14
Endangered organisms
Lesson 15
Australians who study organisms
Set 4
Look for yourself!
Lesson 16
Lesson 17
Lesson 18
Lesson 19
Lesson 20
Looking more closely
Looking around you
Sensing your environment
Animals in your environment
Temperature and rainfall
What happens if?
Lesson 21
Lesson 22
Lesson 23
Lesson 24
Lesson 25
What if there is a bushfire?
What if there is a drought?
What if there is a flood?
What if humans keep making changes?
Over to you
Set 5
Australian environments Set 3
ii
Set 3: Another look at organisms
Contents
What will you learn in Set 3? ...................................................................iii
What do you need for Set 3? ....................................................................iv
Lessons 11 and 12
Adaptations............................................................ 1
Lessons 13 and 14
Endangered organisms....................................... 17
Lesson 15
Australians who study organisms .................... 25
Suggested answers ................................................................................... 29
Send-in pages ............................................................................................ 35
Australian environments Set 3
iii
What will you learn in Set 3?
In Set 3, you will have opportunities to:
•
describe some adaptations of living things
•
explain how adaptations help an organism to survive in its
environment
•
match drawing of animals with their descriptions
•
explain the meanings of extinct and endangered
•
describe why some organisms become extinct or endangered
•
extract information from a media article
•
describe the research of a current Australian scientist
•
discuss the impact (or effects) of this research.
Australian environments Set 3
iv
What do you need for Set 3?
Here is a reminder of the items you need for Set 3.
All lessons
•
various materials, such as books, CD-ROMs, videos and Internet
resources with information about organisms
•
hand lens
Lessons 13 and 14
•
scissors
•
glue or sticky tape
Australian environments Set 3
1
Lessons 11 and 12
Adaptations
Organisms (living things) need all sorts of things to stay alive.
They have to find food, water and shelter. They often have to find
companions and a mate to reproduce. They need to avoid danger
and animals that might eat them.
Organisms have special features to help them to survive.
Different organisms have different features.
These features are called adaptations.
Adaptations make organisms suit their environment.
Some examples of adaptations
1.
An owl hunts small animals such as mice. An owl hunts at night.
It can see very well in the dark.
What features does an owl have to help it to catch its food?
Please check your answer.
2.
Wombats mainly eat grasses. They dig burrows in the ground to
shelter from the heat and to hide from animals that might kill
them. Wombats have poor eyesight but a very good sense of
smell.
What features does the wombat have to help it to survive?
Check your answer now.
Australian environments Set 3
2
3.
A gum tree is a plant. All trees take in water through their roots.
They lose water through their leaves.
Gum trees have deep roots and hard waxy waterproof leaves.
They survive very well in the dry climate of Australia.
Describe some features of the gum tree that help it to survive.
Check your answer.
You have described some features of an owl, a wombat and a gum
tree. These features help them to survive. So these features are
adaptations.
The adaptations of the owl, wombat and gum tree make them
suit their environments.
4.
What is an adaptation?
5.
Emus are tall flightless birds that live in Australia. They eat fruit
and plants. They can run very fast. They have large eyes and
strong beaks. They are a dull red brown colour, like the soil.
Describe some adaptations of the emu.
Well done! You can describe the adaptations of some living things
to their environment.
Australian environments Set 3
3
What about you?
What adaptations do you have? Try these questions.
6.
Why do you think humans have hair on their heads and
lashes on their eyes?
7.
What does your heart do when you have to run quickly?
(This is an adaptation because it helps you to survive.)
8.
What do you do if you feel cold?
(What you do is an adaptation because it helps you to survive.)
9.
Can you think of any other adaptations that you have?
Describe two.
Compare your answers with the ones in the answer pages.
You have adaptations that help you to survive in your environment.
And you’ve noticed that you have different kinds of adaptations.
Adaptations that are features or structures of your body are called
morphological adaptations. Adaptations in how your body works
are called physiological adaptations. Adaptations in how you act
and what you do are called behavioural adaptations.
Australian environments Set 3
4
Kinds of adaptations
Morphological (or structural) adaptations are often visible features
of an organism. They are related to the way the organism looks
or is structured. Here are some examples.
•
Some animals have special colours or patterns, for attracting a
mate or for camouflage (to help the animal to hide).
For example, male bower birds have some bright blue feathers
whereas females are brown.
•
Some flowers have special colours, patterns and perfume to
attract insects and so help the plant to reproduce.
For example, wattles are bright yellow and have strong perfume
to attract bees.
•
Some animals have spines to protect themselves from predators.
For example, echidnas are covered with spiny needles.
•
Some plants have special seeds to protect the seeds or to help them
disperse (spread out). For example, hakea seeds are in a tough pod
that opens after fire. Each seed has a wing to make it fly.
Physiological (or body function) adaptations are related to the way that
an organism carries out its life processes. These adaptations affect the
internal functioning of the organism and usually are not immediately
visible to an observer. Here are some examples.
•
Marsupial animals, such as possums, give birth to tiny babies that
are protected and cared for in a pouch.
•
Humans produce perspiration (sweat) to cool the body down.
•
Kangaroos reduce the amount of water they lose by making their urine
very concentrated (with lots of wastes dissolved in a little water).
Behavioural (or what the organism does) adaptations include
responses to a specific stimuli (things that happen to cause a reaction).
Behavioural adaptations include individual and group responses.
Here are some examples.
•
Penguins huddle together to keep warm.
•
Plants droop their leaves to reduce the amount of water they lose.
•
Kangaroos lick their paws to keep cool.
•
Plants grow towards the sunlight.
Keep these three different kinds of adaptations – morphological,
physiological and behavioural – in your mind as you learn about
the variety of adaptations of some plants and animals.
Choose the ones that interest you from the next 16 pages.
Australian environments Set 3
5
Adaptable plants
Here are some examples of plants with different adaptations.
baobab tree
grass tree
cactus
mangrove
Venus fly trap
stringy bark
10. Use information in the pictures to complete as much of the table as you can.
Plant adaptation
Name(s) of
plant example
special tissue for
holding water
absorbs extra nutrients
by catching insects
narrow leaves to reduce
loss of water
Use the answer pages to fill in any gaps in your table.
Australian environments Set 3
Predict an ecosystem
where it might be found
6
All plants have special features that enable them to survive in the
environment in which they live. They have morphological,
physiological and behavioural adaptations to help them.
Roots
Roots serve two main purposes for a plant.
•
Roots anchor, or hold, the plant in the ground, providing support
for the plant.
•
The plant absorbs all its minerals and water through its roots.
Roots are covered by lots of tiny hairs, called root hairs, which
increase the surface area through which absorption can take place.
Roots usually fall into either of two main types: the tap root or the
fibrous root.
tap root
fibrous root
11. What is an advantage of each of these types of roots for the plant?
tap root
______________________________________________________________________________________
fibrous root
________________________________________________________________________________
Check your answer.
Roots usually behave by growing downwards. But not always!
Australian environments Set 3
7
Some plants live in soggy areas that tend to
have a lot of water around all the time.
An example is mangroves, which grow in
estuaries where a river meets the sea.
Mangroves have special roots called
pneumatophores (say new-MAT-a-faws).
These roots grow upward out of the muddy
river bottom, instead of down, so that the
roots are exposed to air at low tide.
This lets the roots get oxygen so that the cells
in the roots can carry out respiration to get
the energy they need.
mangrove
Roots are also useful for propagating some plants.
(Propagating means making new plants or reproducing.)
Plants such as grasses, some vines and strawberries use runners
either above ground or below ground to reproduce themselves.
grass runners
strawberry runners
An activity for you to try
Go into the garden and see if you can identify some plants that have
runners. Look for vines, grasses and plants used as shrubbery or
ground covers. You may be able to gently pull some up and take
a closer look.
What would happen if you cut these and replanted the cut sections?
Try it. You will need to provide adequate water to these newly
planted sections over the next few weeks for them to keep growing.
Australian environments Set 3
8
Leaves
Leaves are necessary for plants to absorb sunlight (light energy)
for the process of photosynthesis. Photosynthesis is necessary for all
plants to make the sugars (food) they require for their life processes.
Leaves on different plants have different shapes and sizes so that
each plant can maximise its exposure to sunlight, without losing
excessive amounts of water through the leaves.
Look at the examples below.
These leaves are not drawn to scale and are really very different sizes.
baobab
banksia
she oak
bangalow palm
iron bark
blackbean
Big leaves enable the plant to gain maximum exposure to sunlight
but in dry, hot and windy conditions, big leaves will result in the loss
of large quantities of water through stomates in the leaves.
Stomates (or stomata) are tiny structures on the surface of the leaf
that allow gases to move in and out of spaces inside the leaf.
Water moves out of the leaf through the stomates as water vapour.
To reduce this loss of water as much as possible, the majority of
stomates are located on the underside of a leaf, so that they are facing
away from the Sun. The stomates can also be sunken into the leaf so
that they are not directly exposed to light energy.
Australian environments Set 3
9
Some plants, such as the eucalypts, have narrower leaves to reduce
the amount of surface exposed to the Sun. Their leaves are also very
firm and leathery to prevent water loss.
Pine needles are also an adaptation to minimise water loss since the
extremely cold climate where pine trees grow is also very dry.
It is dry because most of the moisture is frozen and so plants need to
reduce water loss by reducing the size of the leaves. Cactus leaves
(the spines) have adapted in the same way, only they have very
swollen succulent stems that hold moisture.
12. Look closely at the diagrams of leaves on page 8.
If you were a plant living in a very hot dry climate,
which leaves would you prefer to have?
How would they assist you in surviving?
Please read the comments in the answer pages.
Leaves also need protection from animals. Some leaves have sharp
spines, serrated edges (bumpy edges like a bread knife) or simply
have a bad taste.
13. Look back at the plants on page 5. Which ones do you think have
adaptations to protect them from predators?
Check your answer.
Leaves also have behavioural adaptations. For example, spinifex grass
can roll its leaves during dry conditions to reduce water loss.
Most plants grow towards sunlight – this is called phototropism.
And of course, there are many physiological adaptations of plants.
For example, plants such as mosses and ferns (that grow under trees
and ledges where it is darker) have adaptations so that they do not
need as much sunlight as other plants for photosynthesis.
Australian environments Set 3
10
Stems
Stems of plants provide support for the plant and enable them to
stand upright. They are either woody or very flexible and filled
with sap.
Plants that grow very tall, such as trees, require extra strength and
tend to have very thick trunks. The branches, however, are more
flexible so that they do not break in the wind.
Plants respond to conditions around them as they grow.
For example, plants in windy areas tend to grow lower to the ground
or to grow in the same general direction as the wind so that they do
not get battered excessively.
Flowers and fruit
Flowers are the reproductive organs of plants. They contain special
structures to enable male sex cells (in pollen) to join with female sex cells
so that seeds form. Every plant species has a specially adapted,
and different, type of flower.
For example, many plants rely on wind to carry pollen from one flower
to another. The pollen must be formed high in the flower, not hidden
away in the petals, so that wind can blow it to another flower.
Flowers that rely on animals to carry pollen have adaptations of
perfume, nectar and bright colours to attract animals. Their pollen
is usually sticky or spiky so that it clings to an animal when it visits
the flower.
The seeds produced by different plants are also unique. If the seed is
to be spread by wind, it is very light and may have wispy attachments
so that it blows away easily. Other seeds are contained in very brightly
coloured fruit, so that animals will eat the fruit and the seeds will be
spread via the animals’ droppings.
Some fruit is very tough and requires very high temperatures, such as
a bushfire, to split it open. This is very common among some native
Australian species. In very dry areas, such as desert regions,
plants have very short flowering cycles, usually coinciding with
periods of rain. The flowers bloom and produce seeds very quickly
so that new seedlings are established before the next seasonal dry spell.
Australian environments Set 3
11
Adaptable animals
Animals are very adaptable creatures and no two species are exactly alike.
They have developed unique features to cope with their surroundings
and have managed to survive in some very desolate places on Earth.
In this section you will look more closely at some adaptations of
animals that assist their survival in different conditions.
Animals on land
Animals that live on land are called terrestrial animals. They need
different adaptations from aquatic animals because they live in a
different environment. What are some of these special features?
Support
Air is very thin compared with water. It does not provide any
support to organisms. Animals need to have very strong skeletons
to hold them up, to protect their organs and to let them move.
Skeletons may be exoskeletons on the outside, such as the ‘shell’
on a beetle. Skeletons may also be endoskeletons, on the inside, such
as the skeleton in your body. Compare the endoskeletons in these
animals.
Terrestrial animals have thicker stronger bones than aquatic animals.
Australian environments Set 3
12
Water loss
Animals on land face a major problem with losing water.
Animals must keep lots of water within their cells – for example,
approximately 70% of human body tissue is composed of water –
because water is essential to maintain life processes.
Animals have behavioural adaptations to help reduce water loss.
They can move away from heat and tend to live close to sources of water.
Most animals will move to search for water in times of drought.
Land animals have internal lungs or respiratory organs to prevent
water loss. Also, their methods of reproduction do not tend to
depend on water. Land animals either produce eggs which contain
their own fluid or rely entirely on internal methods of reproduction.
Availability of light and temperature control
Availability of light is not an issue for animals on land as they do not
gain any direct benefit from exposure to light. However, light is
associated with temperature, which is a major concern for animals as it
is directly related to water loss and maintenance of body temperature.
Temperature varies significantly on land, from place to place,
season to season and on a daily basis within a given region.
Land absorbs heat easily and also loses it quickly; that is why the
coastal regions are usually cooler than inland areas during the day
and vice versa at night.
Animals have some very ingenious ways of avoiding extreme
temperatures. These include the type of body covering they have,
sweating and producing concentrated urine. Many animals burrow
to avoid the hottest part of the day or only come out at night.
The size and shape of an animal is also related to its ability to
regulate its body temperature.
Some animals can change colour to absorb or reflect more light.
For example, some reptiles can go dark when they need to absorb
heat from the Sun’s rays, or get lighter in colour when avoiding
exposure to excess heat radiation from the Sun.
(Snakes are reptiles so their body temperature changes with the
surrounding temperature. They have to absorb or reflect heat to
keep their body temperature in control.)
Australian environments Set 3
13
Colour
Colour can be a very good disguise for animals. This adaptation is
called camouflage and it can help them to hide and to protect
themselves from predators. A camouflaged animal tends to blend in
completely with its surroundings, making it difficult for other
animals to see it.
Colour is also used to attract a mate; for example, male bower birds
collect blue objects to decorate their nests to attract females.
Most male birds are more colourful than the females, which would
usually sit on the nest and so need to blend in with the surroundings.
Obtaining food
Animals have unique adaptations for gathering food, such as:
claws for digging; special teeth for tearing, cutting or chewing food;
scents that lure victims; silk nets that can trap unsuspecting passers;
beaks that can crush, peck or reach into very small places.
Look at these examples.
albatross
wedge-tailed eagle
bridled honeyeater
spoonbill
rainbow lorikeet
long-tailed finch
northern shoveler duck
collared kingfisher
Australian environments Set 3
14
Can you suggest what each of the birds on page 13 might eat?
Hint: Look at the size and shape of the beak. Does it look thin and pointy for getting
into small places, strong and sharp for cutting or tearing, or small for pecking
the ground? Go outside and observe the birds in your garden for a few clues.
Draw up a table with your answers in the space below.
Compare your answers with the ones in the answer pages.
Other adaptations
Some animals have special adaptations to protect themselves.
These include the ability to produce poison, warning scents, noises
and ability to get away from danger.
Think of an animal with a protective adaptation.
Describe it below.
There are some examples in the answer pages.
Australian environments Set 3
15
All animals need some protection from their surroundings.
For example, some have very hairy nostrils and eye lashes to prevent
sand and dust from getting into the eyes or lungs; others have thick
fur to provide insulation or water-resistant feathers to avoid getting
soaked in the rain or water. (Wet feathers would decrease the ability
to fly.) Big eyes assist nocturnal (night) vision and long whiskers can
help animals to sense things in reduced light.
Animals also need to be able to find a mate and many animals have
special morphological, physiological and behavioural adaptations to
make reproduction more likely.
If you are interested in adaptations, there are lots of books, videos
and CD-ROMs that you could investigate to find out more.
Exercise 11
But now it is time to complete the send-in exercise for Lessons 11 and 12.
Australian environments Set 3
16
Australian environments Set 3
17
Lessons 13 and 14
Endangered organisms
Have you seen a dinosaur recently? I don’t mean a photo or a model.
A real dinosaur. No? I wonder why not?
Dinosaurs were large reptiles that lived on Earth millions of years ago.
And now they are no longer here. That diverse group of animals is
now extinct. Extinct means has died out.
No one is sure exactly why the dinosaurs became extinct.
There may have been climate changes or disease; there could have
been a major disaster. The extinction probably took a very long time.
They became extinct because they did not have the adaptations to
survive when their environment changed.
What are endangered organisms?
Living things continue to become extinct, even today.
As well, some organisms are endangered. This means that
there is a high chance that these organisms will become extinct.
Use the pictures of animals on page 41 to complete the diagram below.
Some of Australia's endangered animals
Native cat
Numbat
an animal with
large ears, large eyes
and long whiskers
a furry animal
with a bushy tail
and stripes
Bettong
Orange-bellied parrot
a jumping animal
with large feet and
a rounded body
an animal with
a strong beak
and feathers
Australian environments Set 3
18
More examples
This animal is called
a Thylacine,
or Tasmanian tiger.
It is extinct.
It was hunted by farmers
because it killed sheep.
The forests where it lived
were cut down for wood
and cleared for farmland.
1.
The Thylacine is extinct. What does this mean?
2.
Why is the Thylacine extinct?
This animal is called a long-footed potoroo.
It is endangered.
It has been killed by foxes and wild cats.
The forest where it lives has been changed
by logging (cutting down trees).
3.
The long-footed potoroo is endangered. What does this mean?
4.
Why is the long-footed potoroo endangered?
You have looked at examples of extinct and endangered animals.
All sorts of organisms – plants, animals and decomposers –
can become endangered or extinct.
Australian environments Set 3
19
You have thought about some reasons that organisms become
endangered or extinct. These include:
•
that they are easy prey for predators brought into Australia,
such as foxes, cats and dogs
•
that they have been hunted over many years and so their numbers
are greatly reduced
•
that their natural habitat has been changed by: human activity,
such as clearing for towns, agriculture and industry; the effects of
pollution; the rapid growth of technology.
5.
Here are some steps that are recommended to protect Australian
organisms from extinction. Explain why each one would help.
(a) Pet cats should be indoors animals. They should be shut
inside the home at night.
(b) Cars should be washed on the grass. Waste car oil and
wastes from pets should be disposed of properly and not
washed into street drains and so into rivers and waterways.
(c) Areas of bushland should not be altered until they have been
studied to see which organisms live there.
Compare your explanations with the ones in the answer pages.
Australian environments Set 3
20
Some more of Australia's endangered animals
Read about these endangered animals and look carefully at the drawings.
You will then better understand why they are in danger of extinction.
Western swamp tortoise
This is the world's rarest tortoise and
one of Australia's most endangered
animals. It has been successfully bred
in captivity but less than 300 remain
in the wild.
Bridled nailtail wallaby
This is one of the most beautiful of Australia's
wallaby species. It has been reduced to 10%
of its former range. It was thought to be
extinct until a population was discovered
in central Queensland in 1973.
Northern hairy nosed wombat
This is Australia's rarest mammal
and vies for a lead position among
the world's endangered animals.
Only 65 survive but are protected
in Epping Forest, Queensland,
a scientific reserve of 3 330 hectares.
New words – what do they mean?
In the list below are some words you have just read.
You might like to know what these words mean.
brindled – grey-brown coloured with darker spots or stripes
in captivity – in a human-made enclosure
rare – not widely known, uncommon
range – the limits to which the animal is spread out
vies – competes with other animals
Australian environments Set 3
21
Extract information from the descriptions about these Australian
endangered animals and answer the following questions.
6.
How many western swamp tortoises are there in the wild?
7.
When was the population of bridled nailtail wallabies first discovered?
8.
Where is the only population of northern hairy nosed wombats?
9.
A recovery plan is underway for the bridled nailtail wallaby.
What do you think this means?
10. Why do you think that bridled nailtail wallabies became endangered?
11. Two of the world’s most endangered species are on this
Australian list. Which species are they?
Check your answers in the answer pages.
Australian environments Set 3
22
Some of the world's endangered animals
Many species in other parts of the world are also in danger of extinction.
Read about three other endangered species in the boxes below.
Look carefully at the drawings. Then answer the questions
on the next page.
Giant panda
A cooperative project between the World
Wildlife Fund and the People's Republic
of China began in 1980 to learn more
about the giant panda and to ensure
its conservation. Only an estimated
1 000 pandas remain, all confined to the
bamboo forests of south-western China.
Scarcity led to their adoption as the
emblem for the World Wide Fund for Nature.
Blue whale
The blue whale is found in all oceans. It is the
largest animal on Earth. It has been heavily
exploited in modern times; for example,
in 1930–31, more than 30 000
were slaughtered.
The species was finally
protected in 1967 but
is still endangered.
Aye-aye
Found only in the northern sector
of the east coast rainforests of
Madagascar, this solitary creature
sleeps in a nest by day and feeds on
fruit and insect larvae by night. An
important cause of its disappearance
is prompted by its bizarre appearance;
many Malagasy consider it a creature
of ill-omen to be killed on sight. It has
recently been successfully bred in captivity.
Australian environments Set 3
23
New words – what do they mean?
The following list explains the meanings of some words which may
be new to you.
cooperative – working together, helping
conservation – stopping further killing
estimated – to calculate an approximate number
emblem – a badge or symbol
protected – agreement to defend the animal from harm
solitary – an animal which lives alone
larvae – immature, free swimming stage of insect life
Malagasy – the people of Madagascar
ill-omen – bad luck
Can you extract more information on endangered species?
Answer the following questions.
12. Which animal is used as the emblem for the World Wide Fund
for Nature?
13. Which of the endangered species is the largest animal on Earth?
14. What happened to blue whales in 1930–31? Why?
15. What is an important cause for the disappearance of the aye-aye?
Please check your answers.
Australian environments Set 3
24
Exercise 13
In send-in Exercise 13, you will find out about another endangered or
extinct organism. There are two ways you could do this.
•
You can carry out your own research to find information about
an organism. You need to describe where it lives/lived and why
it is endangered or extinct. You can present your information on
your own paper or in another way that you choose.
You can show that you are performing at a high level in science if
you choose to complete Exercise 13 in this way.
•
If you would like a simple way to complete Exercise 13, read the
information and answer the questions in the send-in pages.
Australian environments Set 3
25
Lesson 15
Australians who study organisms
There are many people in Australia who study living things.
Many of these people have jobs as scientists at universities or at the
CSIRO (Commonwealth Scientific and Industrial Research Organisation).
Your task in this lesson is to learn about what one scientist does.
There are different ways that you can do this.
Choose the way that you will enjoy the most (or follow your
teacher’s instructions).
You could:
❒
❒
❒
read the information and answer the questions on pages 25 and 26
❒
prepare your own report using information that you find for yourself.
If you want to do this, read the instructions on page 28.
use information from pages 26 and/or 27 to complete Exercise 15
use information sent to you by your teacher or information that
you find for yourself to complete Exercise 15
Decide how you will complete this lesson and do it. Happy learning!
Studying Sydney Harbour
Dr Lynne McLoughlin is a biologist at Macquarie University in
Sydney. She has studied how ecosystems around Sydney Harbour
have changed since Europeans first took over the area in 1788. Dr
McLoughlin has found that all areas of the harbour have changed
greatly.
Dr McLoughlin collected information from government records,
newspapers and other reports. She also studied paintings and
photographs taken around Sydney Harbour. She made some
interesting doscoveries.
Mangroves used to only occur around the openings of creeks and
rivers but now they are quite common in the harbour. One reason for
this is that there are more mudflats because soil is being washed into
the harbour from cleared land. Now, communities such as beabches
and saltmarshes are much less common in the harbour.
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The harbour has also been changed by dredging, which means
digging soil from the bottom to make the harbour deeper. This began
in 1842 and continued until the 1960s.
Many of the areas around the harbour have been filed with soil and
garbage and turned into parks. Retaining walls of concrete and stone
replace natural tidal areas.
Dr McLoughlin's research is important because it helps people to see
that 'natural' communities may be due to chan ges that people have
made—they may not be natural at all. It helps people to make
decisions about ecosystems to protect.
1.
Underline the name of the scientist.
2.
Describe what this scientist has found out.
3.
Why is this information useful for Australians?
More Australian scientists
There is information about two more Australian scientists following.
Choose the research that you think is more interesting and use it to
complete the send-in page for this lesson.
Dr Bill Rudman
Dr Rudman works at the Australian Museum in Sydney. It is called
the Australian Museum because it was the first museum established
in Australia (1827). The main areas of research at this museum
include Australian Aboriginal culture and Australian organisms,
rocks and minerals (natural history).
Dr Rudman has studied sea slugs, called nudibranchs, that get most
of the food they need from microscopic plants called zooxanthellae.
These algae (sea plants) naturally grow on the surfaces of corals.
The sea slugs eat the corals, with the algae attached, then keep the
algae alive inside their bodies.
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Sunlight can travel through the bodies of the sea slug to reach the algae,
so the algae can photosynthesise and make sugars. The sea slugs use
these sugars from the algae.
Understanding how these organisms survive together provides
information about the richness of relationships in nature.
Studies of the mechanisms by which sea slugs are able to maintain
algae inside their bodies may assist scientists to understand and
control relationships between other organisms, including parasites
and hosts.
Dr Chris Smith, Dr Warren Bond and Mr Frank Dunin
These scientists from the CSIRO have been working with farmers in
the Wagga Wagga area to measure the amount of water used by
agricultural crops.
Smith, Bond and Dunin used huge pots to hold water under the soil.
By weighing these pots very accurately, they could determine how
much water the plants had used and how much water had leaked
through the soil into the water table. They have been able to compare
the efficiency of different crops to prevent leakage.
Leakage of water is a problem because salt rises towards the surface
when the water table is high. This makes the soil salty, which is
called salination, and reduces the ability of the soil to grow plants.
Contrary to usual thinking, plants that use more water – like the
native plants that were cleared for farming – are better for this area.
This is because they keep the water table lower and so stop salt rising
towards the surface.
Smith, Bond and Dunin have measured the efficiency of several crops
to prevent water leakage. These crops include wheat and triticale,
lucerne and canola. They have also measured the water leakage for
native vegetation. By comparing their measurements, they can make
recommendations about crops that are best for preventing leakage of
water into the water table, and so, best for reducing salination.
So far, their research shows that lucerne is a very good crop for
preventing leakage. They have experimented with farmers and
found that rotating lucerne and another crop reduces the salination of
the soil. The best crop to reduce leakage would be trees but trees
grow too slowly to be a commercial crop in most areas.
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Didn’t like these examples of Australian scientific research?
There is lots of other information from universities and other
organisations available via the web. Think of an idea and search for
information using a search engine.
Exercise 15
You can now complete Exercise 15 in the send-in pages.
If you are preparing your own report make sure that you have:
• identified the scientist(s)
• described what organism(s) the scientist is studying and
what s/he has learned
• discussed how this information could be useful or
perhaps lead to problems.
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Suggested answers
Lessons
11 and 12
Adaptations
Some examples of adaptations
Page 1
Page 2
Page 3
1.
An owl has large eyes to see at night. It has strong wings to fly quickly and
claws to grab small animals. It has a sharp hooked beak for tearing food.
2.
A wombat has a good sense of smell to find food and to avoid animals
that could kill it. It has strong claws and legs for digging.
You might also say a wombat has strong jaws and teeth for chewing grasses.
3.
A gum tree has deep roots to reach for water. It has hard waxy leaves
to prevent water escaping. Because gum tree leaves are hard, they do
not dry out or wilt as quickly as other trees’ leaves.
4.
An adaptation is a feature that helps an organism to survive in its environment.
5.
An emu can run quickly. It has large eyes to see food and enemies and
a strong beak to eat fruit and plants. Its colour helps it to hide.
What about you?
6.
Hair on the head insulates and protects the head. It stops too much heat
being lost and stops the skin from being sunburnt. Eyelashes protect
the eyes because they stop dust and grit getting into the eyes. These
foreign materials could scratch the surface of the eyes and impair vision.
7.
Your heart beats faster (to quickly move sugar and oxygen through
your body to your muscles and to move carbon dioxide to your lungs
to be excreted).
8.
You put on a jumper (or you shiver). Both these behaviours are
adaptations to keep you warm.
9.
You have many adaptations. For example, you have:
• two eyes to enable you to see in three dimensions
•
•
a large brain to solve problems and use symbols and words
a thumb that works in the opposite direction from your fingers
so that you can grasp.
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Lessons 11 and 12 continued
Adaptable plants
Page 5
10. Here are some sample answers.
Plant adaptation
Name(s) of
plant example
Predict an ecosystem
where it might be found
special tissue for
holding water
boabab tree
cactus
desert
absorbs extra nutrients
by catching insects
Venus fly trap
scrubland
ecosystems with poor soils
narrow leaves to reduce
loss of water
boabab tree
stringy bark
desert
scrubland
Roots
Page 6
11. A tap root goes deep into the ground, to get deep water and as an anchor.
A fibrous root spreads out to get water from a large space around the plant.
Leaves
Page 9
12. If you were a plant in a hot dry environment, you may prefer to have leaves like
the banksia, iron bark or she oak. They are thinner than the others and would
reduce the surface area from which water loss, called transpiration, could occur.
13. Grass tree leaves are razor sharp; a cactus has spines; the Venus fly trap
looks spiky but it isn’t.
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Lessons 11 and 12 continued
Obtaining food
Page 14
Here is an example of a suitable table and some suggested answers.
Bird
Possible food
albatross
small prey, aquatic organisms from shallow
water or scavenged on the seashore
spoonbill
crustaceans found in mud or shallow water
northern shoveler duck
scavenges small organisms in shallow water
wedge-tailed eagle
small prey such as rats, lizards, snakes
rainbow lorikeet
nectar and seeds
collared kingfisher
small prey such as lizards, mice
brindled honeyeater
nectar from flowers
long-tailed finch
grass seeds
Other adaptations
For example: spiders and snakes producing venom; kangaroos are able to
move very fast; echidnas have spines; geckos will be pale coloured in areas
with white sand or mottled when surrounded by pebbles of varying colour.
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Lessons
13 and 14
Endangered organisms
What are endangered organisms?
Page 17
Here are the animals.
Native cat
Numbat
an animal with
large ears, large eyes
and long whiskers
a furry animal
with a bushy tail
and stripes
Bettong
Orange-bellied parrot
a jumping animal
with large feet and
a rounded body
More examples
Page 18
Page 19
1.
The Thylacine has died out. There are none of them alive any more.
2.
The Thylacine was killed by people. The places where it lived were
changed or destroyed. It did not have the adaptations it needed to
survive when its environment changed.
3.
The long-footed potoroo might become extinct. There are not very many
of these animals left.
4.
It is killed by foxes and cats. The places where it lived were changed
or destroyed.
5.
(a) Cats are carnivores. They like to hunt at night. Keeping them
inside will stop them from hunting and killing native animals
such as small birds, lizards and mammals.
(b) Wastes should not be put into gutters and so into rivers and
waterways. They could poison or give diseases to native organisms
that live in our rivers and oceans.
(c) A bushland area may be home to an endangered species. If the area
were changed, the species could become extinct. So, the area should
be studied first.
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Lessons 13 and 14 continued
Some more of Australia’s endangered animals
Page 21
6.
less than 300
7.
1973
8.
Epping Forest, Queensland
9.
People are working to help this wallaby survive and reproduce so that
the numbers will increase. The wallabies may be captive or in the wild.
10. Perhaps people have taken its habitat by clearing land for farms?
Perhaps the wallabies’ habitat has been changed in some other way?
90% of the space and resources that the wallabies used to have are now
no longer available.
11. western swamp tortoise, northern hairy nosed wombat
Some of the world’s endangered animals
Page 23
12. giant panda
13. blue whale
14. They were killed by people. People wanted to use them.
(Whale oil can be used as a fuel and to make soap and perfume.)
15. People kill them because they are frightened that the animals will bring
bad luck.
Lesson15
Page 26
Australians who study organisms
Studying Sydney Harbour
1.
Dr Lynne McLoughlin
2.
Dr McLoughlin has found out that the ecosystems around Sydney Harbour
have changed greatly since 1788.
3.
It helps people to make decisions about which ecosystems in Sydney Harbour
should be protected.
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Australian environments Set 3
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Send-in page
Name
Lessons 11 and 12:
Adaptations
______________________________
Exercise 11
This exercise is an opportunity for you to show that you can:
•
describe some adaptations of living things to factors in their
environment
•
write explanations to match the adaptations you select.
Below are some sentences about different plants and animals.
Choose at least one plant and one animal that you would like to
write about.
For each organism you choose:
•
describe two adaptations that benefit the organism
•
explain how each adaptation helps it to survive.
Giraffes
Giraffes are herbivores that live in the drier parts of Africa. Food is
sometimes scarce. They are very tall animals with long necks.
They have patched markings which are similar colours
to the regions where they live.
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Moss
Moss is a plant which does not have true roots. Instead, it is held in
place by fixings called rhizoids. Moss gets its water from the
moisture on the surfaces where it lives. It needs light for
photosynthesis but must live in cool shady places.
Polar bears
Polar bears live on ice and snow in the Arctic. They prey on seals,
penguins and fish. They have thick soft white fur and thick layers
of fat. They have strong sharp claws and can run and swim very
quickly.
Neptune’s necklace
Neptune’s necklace is a sea plant. It is a producer that lives in the
ocean. Most light for photosynthesis is at the water surface. Each
piece of the necklace is filled with air so that it floats. Hundreds of
pieces join together to form a colony of this seaweed.
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Send-in page
Name
Lessons 13 and 14:
Endangered organisms
______________________________
Exercise 13
This exercise is an opportunity for you to show that you can:
•
extract information from a scientific description
•
apply information to explain why adaptations are important.
Below there is information about an endangered reptile called an
angonoka. Read through the information now.
Angonoka
Extremely rare and
in imminent danger of
extinction, the angonoka is
restricted to three islands
of forest in northwest
Madagascar. The species
is entirely herbivorous.
The main threats to its survival are commercial and
subsistence exploitation, habitat modification and predatory feral pigs.
Here are some words from the information that may be new to you.
imminent – just about to happen
herbivorous – the animal is a herbivore
subsistence – day to day survival
exploitation – taking or killing more than are needed
modification – changes
feral – a domestic animal gone wild
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Now read the information about the angonoka again.
Then answer the questions under the information.
1.
What does the angonoka eat?
2.
Underline the words that best match the angonoka.
producer
predator
plant
consumer
prey
animal
3.
Write two reasons that the angonoka is endangered.
4.
How do you know that there are not many angonokas left
in the world?
5.
There are other forest areas near where angonokas live.
Why don’t these animals spread into other areas so that
they can survive?
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Send-in page
Lesson 15:
Name
______________________________
Australians who study organisms
Exercise 15
This exercise is an opportunity for you to show that you can:
•
describe some recent Australian scientific research
•
evaluate what effect this research might have
•
discuss some benefits and possible problems that may come from
this new information.
Complete the tasks below, using information from pages 33 and/or 34
or information your teacher has provided or that you have found for
yourself.
1.
Who is the scientist and what has been discovered?
2.
How might this new information affect other people?
Explain why you think so.
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If you want to prepare your own report, use the lines or space below.
Make sure that you :
• identify the scientist(s)
• describe what organism(s) the scientist is studying and what
s/he has learned
• discuss how this information could be useful or perhaps
lead to problems.
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Endangered Australian animals
Use these drawings in Lessons 13 and 14
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Australian environments Set 3