Essential Idea:
The continued survival of living organisms including
humans depends on sustainable communities
Understandings:
- Species are groups of organisms that can potentially interbreed to produce fertile offspring
- Members of a species may be reproductively isolated in separate populations
- A community is formed by populations of different species living together and interacting with each other
- A community forms an ecosystem by its interactions with the abiotic environment
- Species have either an autotrophic or heterotrophic method of nutrition (a few species have both methods)
- Autotrophs obtain inorganic nutrients from the abiotic environment
- Consumers are heterotrophs that feed on living organisms by ingestion
- Detritivores are heterotrophs that obtain organic nutrients from detritus by internal digestion
- Saprotrophs are heterotrophs that obtain organic nutrients from dead organisms by external digestion
- The supply of inorganic nutrients is maintained by nutrient cycling
- Ecosystems have the potential to be sustainable over long periods of time
Skills:
- Classifying species as autotrophs, consumers, detritivores or saprotrophs from a knowledge of their mode of nutrition
- Setting up sealed mesocosms to try to establish sustainability
- Testing for association between two species using the chi-squared test with data obtained by quadrat sampling
- Recognising and interpreting statistical significance