1. Starter Write down three ways in which these people are the same.
Write down three ways in which these people are different.

2. Variation
Differences between individuals of the same species

3. Variation The characteristics you inherit from your parents
There are two factors which cause variation:
The characteristics you inherit from your parents
AND
The environment in which you live

4. Some characteristics can be both inherited and environmental, for example:
HEIGHT
Height is mostly determined by inheritance, but there are environmental factors such as a poor diet which can stunt growth.

5. Discontinuous variation
Categories
Usually caused by one or two inherited genes
You either have the gene or you don’t

6. Continuous Variation
Either caused by environmental factors, Or Lots of different genes all working together, A combination of both

9. Adaptation

10. Arctic hare Desert hare
What are the differences between these two hares that help them survive?
Arctic hare
Desert hare

11. What are the differences between these two foxes that help them survive?
Arctic fox
Desert fox

12. Adaptations to the cold climate:
Thick oily fur coats
Layers of blubber under the skin
May change colour in the summer
Small ears
Large furry feet
Often longer snout
Rounded body shape

13. Adaptations to the desert climate:
Large thin ears
Little body fat
Thin silky fur
Long limbs to help spread the heat
They often are only active at night
More elongated body shape

14. Question 1
Give an adaptation that helps this plant survive.

15. Question 2
Give an adaptation that helps this plant survive.

16. Question 3
Give an adaptation that helps this plant survive.

18. All our modern breeds of dog are descended from wolves.

19. So what makes dog breeds so different today?
Very fast and agile
Large and strong
Small and friendly
Courageous, with a very strong jaw
Hard-working with a thick coat
Loyal and intelligent

20. Mastiff
Gameskeepers dogs (mastiffs) were big, strong dogs and great companions but they were not aggressive or fast enough to chase after the poachers.

21. What could they do?
Another breed known to them was the bulldog. This was quick and aggressive but not strong enough to pull the poachers down and hold them until a gamekeeper arrived.
Bulldog

22. Humans have changed the way dogs look and act by choosing which dogs to breed together.
Mastiff – large and strong but slow and not aggressive.
Bulldog – Aggressive and quick but small.
Bullmastiff – Large, quick, strong and aggressive
This is called
Selective Breeding

24. Can you get from the word STEM to ROOT by only changing one letter at a time (but not the position of any letter) in 6 steps?
STEM
SEEM
SEAM
REAM
ROAM
ROOM
Root
This is an example of evolution small changes which eventually lead to something completely new