1. National 5 Biology Unit 3
Life on Earth

2. Section 3. 16 – Biodiversity and the Distribution of Life
By the end of this section you should be able to:
Describe the terms biodiversity, habitat and ecosystem.
Describe biotic, abiotic and Human influences that affect biodiversity in an ecosystem.
Describe biotic factors include grazing and predation.
State that pH and temperature are abiotic factors.
State that Biomes are regions of our planet distinguished by their similar climate, flora and fauna.
State that global distribution of biomes can be influenced by temperature and rainfall.
State that an ecosystem consists of all organisms living in a particular area and the non-living components with which the organisms interact.
State that a niche is the role that an organism plays within a community
Give examples of organisms’ interactions with others in the community including competition, parasitism, and predation.

3. Variety of Life = Biodiversity

4. Biodiversity of Scotland

5. Structure of the environment
An ecosystem consists of all the organisms living in a particular area and the non-living parts with which the organisms interact.
The environment is made of many different types of ecosystems, such as seashores, forests, lakes and deserts.
Each ecosystem can be divided into a:
habitat – the non-living (abiotic) part, i.e. the physical area in which organisms live
community – the living (biotic) part, i.e. all the different organisms living in that particular habitat.
Each community is made up of many different populations.
A population is all the members of a particular species living in one habitat – for example, the population of red squirrels in an oak wood.

6. My House – My Habitat
In pairs discuss what there is in your house that helps you to survive.
Note down your ideas on the white boards.

7. Survival List

8. People and their habitats
People can live all over the world.

9. We can do this because we are able to build homes for different conditions.

10. Also we can change our clothes to best suit the temperature around us.
Animal skin and fur act as insulators and keep heat in.
White clothes reflect the heat

11. Surviving in a Habitat
Abiotic factors are the non-living parts of the biosphere, such as light, temperature and weather.
Organisms need to have special features that help them to survive the abiotic factors of their habitat.
These special features are called adaptations.
The animals and plants in a community naturally distribute themselves (spread out).
How are the number and distribution of organisms in a habitat affected by abiotic conditions?

12. All birds have similar characteristics.
But many water birds have features that are different from those birds live on land.
Long legs are good for wading
These wings act as flippers
Webbed feet for swimming

13. Some animals are camouflaged to blend in with their surroundings.
This keeps them safe as it is more difficult for other animals to see them or catch them for food.
This lion blends in well with the grassy background.
These zebra could easily be mistaken for bushes from a distance.
This lizards skin is so similar to the rock colour.

14. Aquatic animals have streamlined bodies to move more easliy in the water.

15. These animals have adapted to live in the hot climate of the desert.
Camels store water in their humps.
Ostriches have long eyelashes to keep out the sand.
Snakes glide across the hot sands and can shed their skin
Camels come in two forms:
Dromedary or Arabian (one hump)
And
Bactrian Camel (two humps) Bactrian Camel
Adaptations:
Humps where they store fat that they can metabolise into water when they are out in the desert where water in is short supply.
Long eyelashes to keep flies and sand out of them.
Lange flat feet so that they can walk in the desert stand and on rock so that they are sure footed.
Their fur can insulate them against the cold in the desert at night by keeping the heat in.

16. These animals have adapted to be more suited to cold temperatures.
Layers of fat keep the seals body warm, and small ears stop heat loss.
Polar bears are kept warm by their body fat.
Deer have a warm layer of fur.

17. Even plants have adapted to their habitats.
The cactus has fleshy stems that store water.
Dandelions seeds are easily dispersed.
The water provides support for this lily as it has less developed roots to hold it in place.

18. Cactus Plants Cactus Plants
Animals have adapted over the millennia but plants have also got to adapt to their environment in order to survive. A good example of this is the Cactus plant which can survive out in the desert in the scorching temperatures with very little water.
Its leaves have developed into spines (almost like needles) to stop animals from eating them and to conserve water loss in the heat as this is where plants lose water from through the stomata (like pores on your skin)
If they have flowers they bloom at night as the animals that will pollinate them only come out at night due to the heat of the desert.
If any one has been to Lanzarote you will see the aloe Vera plant there that can be used to soothe skin when it is burnt. This is just the liquid from the plant as they are so succulent inside the green stalks.
They can also have a waxy coating on their leaves to prevent water loss to the environment due to transpiration.

19. Animals and plants help each other
Protection
Plants and animals depend on each other for a wide variety of things.
Nests to reproduce
Shelter
Food
Gas exchange

20. How is the polar bear suited to its environment?
A polar bear is adapted to live in the North Pole:-
Sharp teeth- to bite fish
Fur- to keep warm
Fat- to keep warm
Large flat paws- to prevent sliding
White fur for camoflage

21. Biodiverstiy and the Distribution of Life
Biodiversity
____________ is the huge variety of living things in a given area. It is incredibly important as all living things interact with and rely on each other. Biodiversity is affected by ____________ ____________, (e.g. grazing, predation and disease), _________ _______, e.g. temperature, rainfall and pH, and by human influences such as air pollution, water pollution, habitat destruction, desertification and overfishing.
biotic
factors
Abiotic factors

22. Term Definition Example
Habitat
the environment non-living (abiotic) zone where an organism lives
Desert
Population
All the members of a particular species in one habitat
Hedgehogs in a field
Community
The living (biotic) part e.g. all the organisms living in that habitat
Forest of trees
Species
a group of organisms in which two individuals are capable of reproducing fertile offspring, typically using sexual reproduction.
Homo sapiens
Producer
Green plants that make glucose from sunlight/CO2 + H20
Green plant
Consumer
An animal that eats other plants and animals
Fox
Herbivore
An organism that feeds on plant material only
Cow
Carnivore
An organism that feeds on animal material only
Lion
Omnivore
An organism that feeds on both plant and animal material
Human
Decomposer
organisms that break down dead or decaying organisms
Worm
Ecosystem
All the organisms - living and non parts of a habitat
Rainforest

23. Living factors e.g. living things and their activities
Term
Definition
Example
Biotic
Living factors e.g. living things and their activities
Gazing, Predation
Abiotic
Non-living factors
pH and Temperature