Species, communities and Ecosystems

Topic 4.1

Essential idea: The continued survival of living organisms including humans depends on sustainable communities.

Understandings

What is the relationship between species, communities and ecosystems?

Levels of organization

3.5.U1 Species are groups of organisms that can potentially interbreed to produce fertile offspring

How many different species do you see in the figure below?

Definition of consumers

3.5.U2 Members of a species may be reproductively isolated in separate populations

Overview of the types of reproductive isolation

3.5.U3 Species have either an autotrophic or heterotrophic method of nutrition (a few species have both methods)

What are the different modes of nutrition found in ecosystems?

Place mouse pointer on the figure to view modes of nutrition for terrestrial and aquatic ecosystems.

Modes of nutrition terrestrial and aquatic ecosystems

3.5.U4 Consumers are heterotrophs that feed on living organisms by ingestion

Which organisms in the diagram below are consumers?

Place mouse pointer on the figure to view which organisms are consumers.

Definition of consumers

3.5.U5 Detritovores are heterotrophs that obtain organic nutrients from detritus by internal digestion

Which organisms in the diagram below are detritivores?

Place mouse pointer on the figure to view which organisms are detritivores.

Definition of consumers

3.5.U6 Saprotrophs are heterotrophs that obtain organic nutrients from dead organisms by external digestion

Which organisms in the diagram below are saprotrophs?

Place mouse pointer on the figure to view which organisms are saprotrophs.

Definition of consumers

3.5.U7 A community is formed by populations of different species living together and interacting with each other

Place mouse pointer on the figure to view relationship between populations and community

Definition of population and community

3.5.U8 A community forms an ecosystem by its interactions with the abiotic environment

Abiotic environment influence on living organisms

3.5.U9 Autotrophs obtain in organic nutrients from the abiotic environment

Autotrophs and inorganic nutrients

3.5.U10 The supply of in organic nutrients is maintained by nutrient cycling

Cycling of nutrients in the environment
Show explanation of how nutrients cycle | Hide explanation of how nutrients cycle
Nutrient cycle in the ecosystem explained

3.5.U11 Ecosystems have the potential to be sustainable over long periods of time

Ecosystems and sustainability

Applications

3.5.S1 Classifying species as autotrophic, consumers, detritovores or saprotrophs from a knowledge of their mode of nutrition

Can you classify the different living species in each cartoon?

Place your mouse on the figure to view the classifications

Practice classifying species using mode of nutrition

3.5.S2 Setting up sealed mesocosms to try to establish sustainability

Mesocosm Page

3.5.S3 Testing for association between two species using Chi-squared test with data obtained by quadrat sampling

Click on Go to Chi-squared Test to view how to complete a Chi-squared test

Go to Chi-squared Test

3.5.S4 Recognizing and interpreting statistical significance

Place mouse pointer on the figure to view relationship between populations and community

Place mouse pointer on the figure to view relationship between populations and community

Practice chi-squared test question
Show Are results statistically significant? | Hide Are results statistically significant
Statistical significance answer
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