a variety of animalslrrpublic.cli.det.nsw.edu.au/lrrsecure/sites/lrrview/... · · 2010-09-10dog...
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Lesson 11/20 More about classifying animals 1
A variety of animals
In this lesson, you will be investigating features that can be used to
classify animals. A feature is something that distinguishes one thing
from another. A feature, or characteristic, may be the way something
looks or some other quality.
Animals, animalsHow many different types of animals are there? You probably realise
that there are lots – over one million! Some are alike and some are very
different.
What sorts of animals live atyour place?
Think about the animals at your place.
Can you think of two animals at your place that are similar?
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What about two animals at your place that are different?
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Here are the animals that are found at Kim’s place.
Bee Fly
Butterfly Moth
WaspCockroach
King parrotDog
SnailSlug
CatMagpie
Animals that live at Kim’s place
© State of New South Wales, Department of Education and Training, 2004
Lesson 11/20 More about classifying animals 3
As you can see, there is a large variety of animals here. To make it easier
to investigate these animals, it would be useful to divide them into
smaller groups.
To do this, you need to look closely at the animals and compare them.
Look for the features that the animals have in common. For example, a
dog and a cat are covered in fur, have four legs and teeth. So you could
put them in the same group.
In the next activity you will sort the animals that live at Kim’s place into
four smaller groups. One group has already been made for you.
Remember there are no ’correct’ answers here. Different people will
make different groups, depending on the features they select.
Activity: Animals, animals
Sort the animals into four smaller groups.
Group 1 dog, cat
Group 2 _________________________________________________
Group 3 _________________________________________________
Group 4 _________________________________________________
Check your response by going to the suggested answers section.
You answers may not be the same as those given in the suggested answer
pages.
How can you classify animals?Think about why you grouped the animals as you did. How did you do
it?
When you compared the animals, you probably looked for similarities
and differences. You put the animals that are alike into the same group.
For example, parrots and magpies have got feathers and wings so I put
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them into the same group. Flies, cockroaches, moths, butterflies, and
bees are in another group because they all have wings and lots of legs.
When Kim classified the animals at her place, she used a range of
features, such as skin covering, number of legs, wings and how they
move. But this makes it really hard to group things. Did you have
trouble classifying the animals? How can classifying animals be made
easier?
All the living things on the planet make up one very large group.
It would be much easier if you used just one feature to divide the group
into a small number of groups.
In this Part, you will be dividing animals into two major groups based on
one feature. This will make classifying much simpler. But which feature
should you choose?
Let’s investigate a variety of features that
could be used to classify animals.
Describing similarities and differences
Similarities
• A dog is similar to a cat because they are both covered in fur.
• Both dogs and cats have four legs.
• Neither dogs or cats have feathers.
• Dogs and cats are alike because they have warm blood.
• One feature that dogs and cats have in common is teeth.
Differences
• Dogs are different from birds because dogs have fur but birds have
feathers.
• Dogs differ from birds because dogs have four legs but birds have
two.
• Birds have beaks but dogs do not.
• Birds lay eggs whereas dogs have young born alive.
Lesson 11/20 More about classifying animals 5
You'll need to write about similarities and differences in the next section
about the features of animals.
The features of animals
There are many features that you can use to classify animals. But some
features are more useful than others. Useful features lead you to group
animals that are similar.
Let’s try to deduce (work out) whatsorts of features are most useful forclassifying animals.
The features you’ll consider are:
• habitat, or where the animal lives
• usefulness to humans
• colour
• behaviour, or how the animal acts and responds
• body structure, or the parts of the animal's body.
Habitat – where an animal lives
From the top of mountains to the bottom of the sea, there are many
places where plants and animals can live. There are four main habitats –
water, underground, land and the air. Investigate one habitat to see how
useful it is when classifying.
Activity: Habitat – where an animal lives
Read the passage on the next page called ‘The tale of Salty Sam’. As
you read, underline the names of the animals.
And notice that the passage is a story – it is very different from the
scientific definitions you have been reading and writing.
Try to identify the features of the story that make it different from the
way definitions, or report text types, are often written.
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Put a cross in the box if the feature is not in the story of Salty Sam.
Here are some of the featuresof scientific definitions:
Definitions are written in present tense
Definitions often contain technical words
Definitions are usually generalised
Definitions are objective.
The tale of Salty Sam
Salty Sam was a fisherman who sailed the ocean blue. Everyday
he would go out in his boat, cast his net and haul in his catch.
Some days were good, some were bad.
Things were not going too well for Salty. His boat needed repairs,
his wife was sick and his children had no shoes. He really needed
to make some money. Everyday he went out, fished and caught
only enough for the family to eat. Things were grim indeed.
It was a Monday, like any other Monday. At least, that’s what
Salty thought. As usual, he cast off, sailed out of the harbour and
threw out his net. Then, as usual, he started to haul in his net. But,
instead of the net being easy to pull in, it was incredibly heavy. He
strained against the weight. He pulled, tugged, gritted his teeth and
struggled with the weight until at last the net was once again on the
deck.
He could not believe his eyes. He rubbed them and surveyed the
catch with his mouth open in disbelief. This would have to be the
strangest collection of animals that he’d ever landed.
'What will I do with all these animals?' he thought. 'I know, I’ll sell
the animals that can be eaten to the local shops – the squid and
sardines to the Italian restaurant, the tuna to the Japanese
restaurant, the crab and the shark to the fish and chip shop.'
'What about the rest of the catch?' He looked at each animal in
turn. The sea urchin and the starfish he could sell to the shop that
sells sea shells and dried sea animals to the tourists. The jellyfish?
Well, nobody needed or wanted that so he threw it over the side.
So off went Salty Sam, smiling and happy. What a day!
Lesson 11/20 More about classifying animals 7
Check your response by going to the suggested answers section.
tuna
shark
jellyfish
sardine
starfish
sea urchin
squid
mud crab
© State of New South Wales, Department of Education and Training, 2004
The drawings above show the sea creatures that Salty Sam caught that
day.
Can you identify a feature that all these animals has in common?
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All these animals live in water.
Apart from their common habitat, these animals are not very similar at
all. They are very different sorts of animals.
Therefore, habitat is probably not a useful feature to use when we
classify animals.
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Usefulness to humans – Salty Sam’sclassification system
Salty Sam decided to use usefulness to humans as his classification
system. He divided his catch into three different groups:
Group 1: animals that can be eaten – squid, sardine, shark, crab, tuna
Group 2: animals for decoration – starfish, sea urchin
Group 3: animals that have no use – jellyfish.
The next exercise will help you to decide the value of using a feature
such as usefulness to humans when you are classifying animals.
Activity: Salty Sam’s classification system
Answer the questions below.
1 Compare the first two animals from Salty’s Group 1. How are these
animals different from each other?
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A sardine has fins and a tail but a squid doesn’t. A squid has tentacles but a
sardine doesn’t. A sardine has gills and scales but a squid doesn’t.
2 Is a squid similar to a sardine?
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They are not really alike at all, except that they both can be eaten and live
in the sea.
3 Are the squid and sardine similar to any other members of Group 1?
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The sardine is more like the tuna and shark than any other group member.
The squid is like nothing at all.
Do you think usefulness to humans is a feature that is very helpful when
classifying?
Not really
Lesson 11/20 More about classifying animals 9
The animals in each group ended up being more different than alike.
However, usefulness to humans is a very common non-scientific
classification system. For example, it’s used to separate useful and
useless plants and animals, such as garden plants and weeds, or food
plants and animals from those not eaten.
Colour
Think of all the animals you know that are blue. Blue swimmer crabs,
blue-ringed octopuses, bluebottle jellyfish, blue wrens and blue whales
are just some examples.
Blue whale
Blue wren
BluebottleBlue swimmer crab
Blue-ringed octopus
Some blue animals
© State of New South Wales, Department of Education and Training, 2004
Look at whether colour is a useful feature for classifying animals.
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Activity: Colour
Use the animals from the above picture to answer the questions below.
1 Choose two animals. What feature do they have in common?
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2 How are the two animals that you have chosen different?
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3 Are the two animals similar to any other members of the group?
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4 Is colour a useful feature to use for classifying animals? Explain
your answer.
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Check your response by going to the suggested answers section.
Colour is not a very useful feature for classifying animals because the
animals in the group have more differences than similarities.
Behaviour
Animals could be grouped according to their behaviour, or what they do.
For example, you could classify animals by the way they move – whether
they are swimmers, crawlers, fliers or runners.
Lesson 11/20 More about classifying animals 11
Let’s investigate animals that fly.
The picture following shows a group of animals that fly: a bee,
dragonfly, cockatoo, pelican and a bat.
bee
bat
cockatoo
dragonflypelican
Some flying animals
© State of New South Wales, Department of Education and Training, 2004
Preparing for the Exercise
Compare these flying animals. Make a list of some similarities and
differences of these animals in the exercises.
Go to the exercises section and complete Exercise: – A variety of
animals.
And here's another problem with using behaviour to classify animals.
Imagine that you step on an insect while you are out walking. It's a bit
crushed but definitely dead! You take it home to try to identify it.
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If your classification system used behaviour, what could your insect do?
Nothing because it is dead! Behaviour is not a really good feature to use
when classifying animals since animals are often dead when they are
being classified.
Body structure
Body structures, or structural features, are the parts of an animal’s body,
such as legs, wings, heart, bones, tentacles, blood, beaks, feathers, fur
and scales.
Look again at the picture offlying animals.
Activity: Body structure
Name the animal(s) with:
1 wings ________________________________________________________
2 bones _________________________________________________________
3 feathers. ______________________________________________________
Check your response by going to the suggested answers section.
Modern biologists classify animals using structural features because they
are easy to observe. Structural features are also used for classification
because scientists think that they show the evolutionary development of
animals over millions of years. You'll learn more about this later in your
science course.
Most features that you looked at in this lesson didn’t turn out to be very
useful to scientists for classifying animals. All the features could be used
– and there are times and situations where they are appropriate.
However, body structures is the only feature that biologists have chosen
to use in a scientific classification system.
Lesson 11/20 More about classifying animals 13
The other features you considered have been used in classification
systems in the past.
In the next lesson, you will be looking at one way that animals were
classified in ancient Greece.
Activity: Summary
Fill in the blanks using the following terms:
similar million not
• There are about one _________________ different types of animals.
• Habitats, colour and behaviour are ____________ useful features
for classifying animals.
• Animals are grouped according to how ___________ they are.
Check your response by going to the suggested answers section.
What did you achieve?Tick what you can do.
compare and contrast the features of various organisms
using animal examples, describe why features such as habitat,
usefulness to humans, colour and behaviour are not very useful
for classifying in science
judge whether a passage has features of a scientific definition
Lesson 11/20 More about classifying animals 15
Suggested answers
Check your responses against these suggested answers.
Animals, animals
My groups are as follows:
Group 1: dog, cat
Group 2: parrots, magpies
Group 3: snails, slugs
Group 4: flies, cockroaches, moths, butterflies, bees.
Habitat – where an animal lives
'The tale of Salty Sam' has none of the features of scientific definitions.
• Definitions are written in present tense.
The story is in past tense. It has words such as was and
went and lots of verbs with -ed endings.
• Definitions often contain technical words.
The story uses common, everyday words.
• Definitions are usually generalised.
The story is specific, not generalised. It is about one
particular Monday.
• Definitions are objective.
The story is not objective because it tells you about how
Salty Sam feels.
Colour
Here are some sample answers. Your answers may be correct even if they are
not exactly the same. This is because you might have described different
animals or chosen different ways to write about similarities and differences.
1 Both the blue swimmer crab and the blue whale are coloured blue. They
also both live in the sea.
2 The crab has many legs whereas the whale has none. The whale has
flippers but the crab doesn’t. Unlike the crab, the whale has a long smooth
body.
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3 The crab and the whale are not like each other or similar to any other
members of the group.
4 Colour is not a useful feature since you end up with groups that have only
one main feature in common – their colour. Apart from that, they are not
similar at all.
Body structure
The animal(s) with the following are:
1 wings: cockatoo, dragonfly, pelican, bee, bat
2 bones: cockatoo, pelican, bat
3 feathers: cockatoo, pelican.
Summary
• There are more than one million different types of animals.
• Habitats, colour and behaviour are not useful features for classifying
animals.
• Animals are grouped according to how similar they are.
Lesson 11/20 More about classifying animals 17
Exercise
Living things Name ___________________________
Teacher ___________________________
Exercise – A variety of animals
Compare five flying animals – a bee, pelican, dragonfly, cockatoo, and a
bat.
bee
bat
cockatoo
dragonflypelican
© State of New South Wales, Department of Education and Training, 2004
Write sentences describing at least three similarities and three differences
of these animals.
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Similarities
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Differences
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