Science 7Text: Discovering Science 7

Unit One:Interaction Within Ecosystems

Chapter 1, “An ecosystems is all the living and non-living things in a particular place.”

Organisms – living things within an ecosystems. Ex. Worm, tree, whale, bird, dog,…

Adaptations – inherited characteristics which help an organism to survive. Ex. Webbed feet, feathers, scales, claws, …

Habitat – the particular place where an organism lives. Ex. Pond, tree, field, soil, rotting log, …

Types of Ecosystems inAtlantic Canada

• Coastlines and Oceans• Freshwater Ecosystems:

(Rivers and Ponds)

• Arctic• Forest

* Organisms survive in their ecosystems according to their “range of tolerance.”

Abiotic Parts of an Ecosystem

• Light and Light Intensity• Temperature• Soil• Air and Wind• Water

Biotic Parts of An Ecosystems• Virus• Bacteria• Algae• Mammals• Reptiles• Amphibians• Marsupials• Raptors• Crustaceans• Plants

Levels of Organization

• Individual – one

• Populations – many individuals

• Community – interactions of many species

• Ecosystems – interactions of living and non-living things

Each species in a community has a specific role to place. These roles make up an ecological niche, which includes where it lives, how it obtains it’s food, and how it affects its environment.

Chapter 2, “Living and non-living things interact in ecosystems.”

Types of Interactions:Symbiosis

• Parasitism – One organism benefits (parasite) and the other is harmed (host).* Internal parasites. Ex. Tapeworm* External parasites. Ex. Tick

• Mutualism – Both partners benefits. Ex. Lichen (Alga and fungus).

• Commensalism – One organism benefits and the other neither benefits or is harmed. Ex. Clownfish and anemone; whales and barnacles.

Roles of Organisms in the Ecosystem

• Herbivores – Plant eating. Ex. Moose, Rabbit,…

• Carnivores – Meat Eating. Ex. Owl, Spider, …

• Omnivores – Plant and meat eating. Ex. Bear, mouse, …

Roles of Organisms in the Ecosystem

• Consumers – Organisms that get their food from the biotic environment by eating (consuming) other organisms. Ex. Fox eats mouse, shark eat small fish, …

• Producers - Organisms that produce their own food. Ex. Plants

• Decomposers Scavengers – organisms that live off the dead, decaying or waste matter of other organisms. Ex. Vulture, bacteria, fungus, …

Keeping Food from RottingPreserving food – Preventing the Growth of Micro-Organisms

• Salting• Smoking• Pickling• Freezing• Vacuum packing• Canning and Bottling• Chemical Additives• Drying

The Food Chain

Food Web

Nutrient Cycle

Chapter 3, “Natural events and human activities cause changes in ecosystems.”

Succession

• The process by which a biological community changes over time. Pioneer Species and Climax Community

The Impact of People on Ecosystem

• Changing Ecosystem – Deforestation, over-fishing, land fill sites, oil spills, mining, acid rain, Farming pesticide/herbicides and monoculture…

• Habitat Loss – Urbanization (city building)

• Endangered and Extinct Species

• Introduced Species – native species (fox and polar bear) and introduced species (moose).

Endangered Species

Extinct Species

Atlantic Cod FisheryCauses of the Fishery Decline

• New fishing technology made it easier to find and catch fish.

• More demand for fish from the world market.• Lack of conservation by governments.• Unsustainable harvesting – catching too much

fish. ** Sustainable vs. Unsustainable

Fishing technology and Innovation

Monitoring and Managing Ecosystems

• Environmental monitoring helps detect and predict changes in the habitats of organisms. Environmental impact assessments using data/information collected through short term and long term monitoring can be used to make appropriate decisions to ”prevent” the destruction of habitats and “protect” the lives of wild species.

• Baseline Data• Permanent Plots

Unit OneSummary Review – pages 96 - 97

• Students must realize that the textbook is the main source of information, especially when preparing for an end of unit test.

• Worksheets, Guide Notes, PowerPoint Presentations, etc are supplementary to the textbook.

• Students should be reviewing materials presented in class on a continuous basis as part of a regular home study schedule.