4.1 - Species, Communities, & Ecosystems
Essential idea:
The continued survival of living organisms including humans depends on sustainable communities.
Nature of science:
Looking for patterns, trends and discrepancies—plants and algae are mostly autotrophic but some are not.
Understandings:
4.1.U1 Species are groups of organisms that can potentially interbreed to produce fertile offspring.
4.1.U2 Members of a species may be reproductively isolated in separate populations.
4.1.U3 Species have either an autotrophic or heterotrophic method of nutrition (a few species have both methods).
4.1.U4 Consumers are heterotrophs that feed on living organisms by ingestion.
4.1.U5 Detritivores are heterotrophs that obtain organic nutrients from detritus by internal digestion.
4.1.U6 Saprotrophs are heterotrophs that obtain organic nutrients from dead organisms by external digestion.
4.1.U7 A community is formed by populations of different species living together and interacting with each other.
4.1.U8 A community forms an ecosystem by its interactions with the abiotic environment.
4.1.U9 Autotrophs obtain inorganic nutrients from the abiotic environment.
4.1.U10 The supply of inorganic nutrients is maintained by nutrient cycling.
4.1.U11 Ecosystems have the potential to be sustainable over long periods of time.
Applications and skills:
4.1.S1 Classifying species as autotrophs, consumers, detritivores or saprotrophs from a knowledge of their mode of nutrition.
4.1.S2 Setting up sealed mesocosms to try to establish sustainability. (Practical 5)
4.1.S3 Testing for association between two species using the chi-squared test with data obtained by quadrat sampling.
4.1.S4 Recognizing and interpreting statistical significance.