1. Earth’s Spheres

2. Is there life on this planet?

3. Life on Planet Earth
What special features and conditions does Earth have that make life possible?
Some people say that Earth itself is a living organism. Does that seem possible to you?

4. Earth’s 4 Spheres

5. The Atmosphere What is it? What is it made of? What does it hold in?
A layer of gases surrounding the earth.
What is it made of?
Nitrogen, Oxygen, Carbon dioxide, Water vapour, other gases
What does it hold in?
Thermal energy
What does it block out?
Ultraviolet light
After students complete the table above, ask them which features of the atmosphere help make life possible. Have volunteers supply answers. Point out that:
• all living things need water, carbon dioxide, and oxygen
• thermal energy held in keeps temperatures moderate for life
• UV light blocked helps protect life

6. Lithosphere
Earth’s Solid Outer Layer

7. All of Earth’s water, in solid, liquid, and gas form.
Hydrosphere
All of Earth’s water, in solid, liquid, and gas form.

8. Biosphere The zone around the earth where life can exists.
Locations where life can exist within the atmosphere, lithosphere, and hydrosphere.

10. Ecology
Ecology is the study of how organisms interact with one another and with their environment.

11. Ecosystems
An area in which living organisms interact with other living components (biotic) and non-living components (abiotic)
All the living organisms that share a region and interact with each other and their non-living environment.

12. Abiotic Factors
The non-living components of an ecosystem.

14. Abiotic Factors
Sunlight - provides energy for all living things.

16. Water - all life processes depend on water.
Abiotic Factors
Water - all life processes depend on water.

18. Abiotic Factors
Soil - determines the types of plants that can live in a certain location.

20. Abiotic Factors
Temperature - determines the organisms that can live there.

22. Oxygen - most living things require it to live.
Abiotic Factors
Oxygen - most living things require it to live.

23. Biotic Factors
The living or once living parts of an ecosystem. Ex: plants and animals.

24. Biotic and Abiotic Influences on Ecosystems
A limiting factor is anything that keeps the population of a species from getting too big
Ex) availability of food, water, human influence

25. Abiotic Factors
All species have a tolerance range that they can survive in (optimal range = best conditions)
This tolerance range dictates where the species will be successful
Eg) tolerance range of a grizzly bear vs a polar bear

26. Biotic Factors
Interactions between individuals often influences population size
Ex) competition between a maple tree and a birch tree for soil nutrients, light, etc

27. Cont’d Interactions can involve other dynamics such as:
Competition = vie for same resource
eg) Lions and Hyenas both eat antelope
Predation = one organism feeds one another
eg) Lion eats an antelope
Mutalism = both organisms benefit
eg) bee and flower
Parasitism = one lives on or feeds on another host
Eg) tape worm and human
Commensalism = one benefits, other neither benefits or is harmed eg) bird living in a tree