1. Interactions Within Ecosystems
Grade 7 Science Unit 4
Interactions Within Ecosystems

2. What is Ecology?
The study of the relationships between living organisms and their environment.
Scientists who study these relationships are called ecologists.

3. Ecosystem: What is it?

4. What is an Ecosystem?
The interactions between living and non- living things in a particular environment.
E.g. A rotting log is an example of an ecosystem. The organisms living in and on the log and the soil, temperature, and other non-living features around the log are interacting.

5. Ecosystems...
Can be described by the types of organisms and the conditions found there.
include abiotic (non-living) and biotic (living) things.

6. Can be large or small.

7. Living Things Local Conditions
Let’s go Outside…
School yard activity
Local Area:
Living Things
Local Conditions

8. The Abiotic Environment
The non-living parts of the environment.
The upper and lower limits in which an organism can survive is called the organism’s range of tolerance.

9. Examples include... Intensity of sunlight Temperature Soil
Abiotic Factors:
Examples include...
Intensity of sunlight
Temperature
Soil
Air and wind
Water

10. The Biotic Environment
The living parts of the environment.
Includes MANY species of organisms ( living things).
Species: a group of organisms that can reproduce to produce similar, fertile organisms.

11. What do living things need for survival?
With a partner, generate a list of the things that all living things must have for survival.

12. The Needs of Living Things
All living things from spiders, to sunflowers, to humans need…
Food
Water
Habitat
Air (gas exchange)
Living things are always interacting with each other and with the non-living things in their environment.

13. Adaptation
Adaptation: is an inherited characteristic that helps an organism survive and reproduce in its environment.
E.g. A duck has webbed feet so it can swim well
E.g. Many birds have hollow bones so they can fly easily.
Living things are adapted, so they 'fit' into
their surroundings, to ensure survival.
– Inherited: you were born with the
adaptation. For example: A bear can survive a
harsh winter because it hibernates.

14. Continued…
There are however many characteristics that help animals survive in their environment that are learned.
E.g. Humans learn to look both ways before crossing the street.
These however, are not adaptations.

15. Can you remember what an Ecosystem is?
An ecosystem is the interactions between living and non-living things in a particular environment.
What is a Biome?
Complete the Biome Worksheet

16. Levels of Organization
ecosystem
community
population
individual

17. The Roles of Organisms in an Ecosystem
Niche: The role of an organism in its ecosystem.
To determine an organism’s niche, you must look at what it eats, where it lives, and how it interacts with other organisms in its ecosystem.

18. Interactions Between Living Things in an Ecosystem
Symbiosis: Occurs when two species live closely together in a relationship that lasts over time.
Can you think of any examples??

19. 3 Types of Symbiosis
Mutualism: Each partner benefits from the relationship!
e.g. The remora fish uses suckers on its head to attach itself to a shark. It then eats the bacteria living on the shark’s skin.
Other examples??

20. Continued…
Parasitism: One partner benefits from the relationship and the other is harmed.
Which is which?? Parasite or host??
Examples: tapeworm, mosquito, leech

21. Types of Ecosystems...
Ocean
Forest
Pond
Arctic

22. Use your textbook and the internet to complete the following chart on each type of ecosystem.
Flora
plants
Fauna
animals
Abiotic
Cond.
1. Oceans
2. Forest
3. Pond
4. Arctic

23. Field Trip to the Schoolyard

24. Habitat –vs- Niche
Habitat: the organism’s address; where does it live? Ex. A moose’s habitat is the boreal forest.

25. Niche: the organism’s job; what role does the organism play in its environment. It includes:
where it lives
how it obtains food
how it affects its environment

26. Ex. A moose lives in the boreal forest, it is a herbivore (plant eater), it provides a home for parasites and it provides food for coyotes.

27. Interactions in the Environment
Biotic - abiotic

28. Abiotic - abiotic

29. Biotic - biotic