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© OUP: To be used solely in purchaser’s school or college
Variation and classification
Variation
Classification
7D
7D Variation and classification
© OUP: To be used solely in purchaser’s school or college
How many different types of living things are there on Earth?
Do members of the same species look exactly the same?
7D Variation – What is a species?
Scientists have identified almost 2 million different types of living things.
Each different type of living thing is called a species.
Many more are yet to be discovered and scientists estimate there could be up to 30 million different types of living things!
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7D Variation – Similar but different
Members of the same species can breed together to produce fertile offspring.
A species is a group of living things with similar features.
All dogs are members of the same species but they don't all look the same.
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7D Variation – Similar but different
Name 5 ways in which these dogs are similar.
Name 5 ways in which these dogs are different.
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Differences between members of the same species are called variation.
7D Variation – What is variation?
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Give 5 examples of variation between humans.
What do you think causes variation?
7D Variation – What is variation?
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7D Variation – Causes of variation
Which type of variation is described by each definition?
A This type of variation is passed on in genes from
parent to offspring.
B This type of variation is
influenced by living conditions and surroundings.
Variation is caused by environmental or inherited factors.
environmentalinherited
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How many inherited characteristics can you think of?
Blood group is another example of inherited variation.Your blood group will never change.
In humans, inherited characteristics include the colour of your eyes and hair.
7D Variation – Inherited factors
Inherited variation is caused by the genes passed on from parent to offspring.
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Environmental variation is caused by differences in living conditions and surroundings.
Climate and food supply are environmental factors that influence all living things.
How might these factors cause variation?
7D Variation – Environmental factors
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7D Variation – Environmental factors
Name another way in which their environment may have influenced these people.
Your country and culture can cause environmental variation.
For humans, environmental factors can influence the way you look, speak and how you do things.
A Sikh grows his hair long because it part of
his culture.
A Buddhist monk shaves off all his hair because it is
part of his culture.
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7D Variation – Inherited factors
Can you think of other inherited characteristics that might be affected by environmental factors?
Some musicians are born with natural talent for music, but they have to practise to to play really well.
Some inherited characteristics can be affected by environmental factors.
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Decide which characteristics are inherited, environmental or both?
7D Variation – Inherited, environmental or both?
inherited environmental both
blood group
wears glasses
tongue rolling
freckles
speaks Italian
dyed pink hair
natural eye colour
height
Welsh accent
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7D Variation – Variation in plants
Are plants also affected by environmental conditions?
Sunflowers were grown in a warm environment under different conditions of soil, water and sunlight.
Experiment Fertile soil Water Sunlight Results
3
2
1
4
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What are the best conditions for growth of the sunflowers?
How might sunflower growth be affected if grown in a cooler environment?
How could you test your prediction?
7D Variation – Variation in plants
Experiment Fertile soil Water Sunlight Results
3
2
1
4
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7D Variation – True or false?
1. Members of the same species all look exactly the same.
True or False
Click on the box to start the quiz
1. Members of the same species all look exactly the same.
FALSE! Members of the same species have similar features but do not look exactly the same.
6. The ability to roll your tongue is an inherited characteristic.
TRUE! Have you inherited this type of variation?
6. The ability to roll your tongue is an inherited characteristic.5. Identical twins are more alike than most but even they are not exactly the same.
TRUE! Identical twins inherit the same features but they have different fingerprints.
5. Identical twins are more alike than most but even they are not exactly the same. 4. Variation caused by environmental factors can be passed from parent to offspring.
FALSE! Only inherited characteristics are passed from parent to offspring.
4. Variation caused by environmental factors can be passed from parent to offspring.3. Variation only occurs in animals.
FALSE! Variation occurs in all living things, including plants.
3. Variation only occurs in animals. 2. Only living things that are members of the same species can breed together to produce fertile offspring.
TRUE! Some species can be interbred. A mule is a cross between a horse and a
donkey, but it cannot produce fertile offspring.
2. Only living things that are members of the same species can breed together to produce fertile offspring.
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Classification
7D Variation and classification
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7D Classification – Sorting living things
Living things can be grouped based on the similarities and differences between them.
For example, all cats are similar to other cats, but very different from caterpillars.
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7D Classification – Sorting living things
What two groups would you classify these living things into?
Sorting similar living things into groups is called classification.
starfish
hamster
horsechestnut tree
wheat
daisies
polar bear
butterfly
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Classification starts by sorting all living things into 5 main groups called kingdoms.
Can different plants and animals be sorted into groups?
Most living things belong to the animal kingdom or the plant kingdom.
Living things
7D Classification – Kingdoms
fungi plants ProtoctistaProkaryotesanimals
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7D Classification – Classifying animals
Where does it live?
Is it covered in feathers?
Is it bigger than a dog?
How many legs does it have? Does it have
a backbone?
What other questions could you ask to classify animals?
Which of these questions is the most important when classifying animals?
There are lots of questions you might ask to continue classifying animals into smaller groups.
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7D Classification - Vertebrates and invertebrates
The most important question to ask when classifying animals is: Does it have a backbone?
So the animal kingdom is divided into 2 groups:
animal kingdom
animals with backbones
animals without backbones
elephantbird
fish
crab
worm
spider
snail
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7D Classification - Vertebrates and invertebrates
These two groups of animals are given special names:
Which name describes which group of animals?
Which group do humans belong to?
invertebrates
vertebrates
animal kingdom
animals with backbones
animals without backbones
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7D Classification - Vertebrates
Vertebrates are classified into 5 groups.
Complete the table of features for each type of vertebrate.
mammals birds reptiles amphibians fish
body covering
how it breathes
where it lives
how offspring are produced
hairy or furry skin
soft, moist skin (no scales)
lungs
mostly on land
lay eggs (in water)
lungs lungs lungs gills
featherstough skin with scales
scales
mostly on land
on landon land and
in waterin water
most young born alive
lay eggs lay eggs lay eggs
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7D Classification – Naming living things
Classification divides each kingdom of living things into smaller and smaller groups.
Kingdom
Phylum
Class
Order
Family
Genus
Species
Plant
Vascular
Lilidae
Monocotyledon
Liliaceae
Narcissus
pseudonarcissus
Animal
Chordata
Mammal
Carnivore
Canine
Canis
familiaris
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7D Classification – Naming living things
Scientists give all living things a special name with two parts:- the first part is the Genus name - the second part is species name
The scientific name for a domestic dog is Canis familiaris.
What is the scientific name for a daffodil?
Kingdom
Phylum
Class
Order
Family
Genus
Species
Animal
Chordata
Mammal
Carnivore
Canine
Canis
familiaris
Plant
Vascular
Lilidae
Monocotyledon
Liliaceae
Narcissus
pseudonarcissus
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Living things have different “common” names in different languages.
All living things have the same scientific name in any language.
How does scientific classification make it easier for international scientists to talk about living things?
7D Classification – Why is classification important?
Carassius auratusscientific name
pesce rossoItalian
GoldfischGerman
pez de coloresSpanish
poisson rougeFrench
goldfishEnglish
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7D Classification – Quiz
2. The largest type of group of living things is called a…
a) kingdom.
b) queendom.
c) princedom.
1. Sorting things into groups is called…
a) magnification.
b) fabrication.
c) classification.
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7D Classification – Quiz
3. The smallest type of group of living things is called a…
a) vertebrate.
b) species.
c) fungus.
4. Why do scientists classify living things into groups?
a) To list living things in alphabetical order.
b) To see how living things are related to each other.
c) To arrange living things in order of size.
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7D Classification – Quiz
6. What do vertebrates have in common?
a) They all walk backwards.
b) They all have a backpack.
c) They all have a backbone.
5. Animals are divided into two main groups called…
a) cats and dogs.
b) fish and mammals.
c) vertebrates and invertebrates.
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7D Classification – Quiz
8. Dolphins live in water and give birth to live young that feed off their mother's milk. What kind of vertebrate are dolphins?
a) Mammals.
b) Fish.
c) Amphibians.
7. What is the body covering on reptiles?
a) Soft, moist skin with no scales.
b) Soft, moist skin with scales.
c) Tough, hard skin with scales.