2 5.1.1: DefinitionsEcologyThe study of the relationship between living organisms and between those organisms and their environmentEcosystemA community and its abiotic environmentPopulationA group of organisms of the same species who live in the same area at the same time
3 5.1.1: Definitions Community Populations of different species in the same area which are interactingSpeciesA group of organisms which can interbreed and produce fertile offspringHabitatLocation within which a species normally lives
4 5.1.2: Autotrophs & heterotrophs ProducerAn organism that synthesises its organic molecules from simple inorganic moleculesHeterotrophconsumerObtains organic molecules from other organisms
5 5.1.3: Consumers, detritivores, saprophytes An organism that ingests other organic matter that is living or recently deadDetritivoresAn organism that ingests non-living organic matterSaprophytesAn organism that lives on or in non-living organic matter, secreting digestive enzymes into and absorbing the products of digestion
6 5.1.4: Food chainsFood chains show a simple linear flow of “who eats who”Therefore shows the energy flowing through the links in the chainQuestions to consider!How is energy lost in the chain?Why are big, dangerous predators so rare?
8 5.1.5: Food websA diagram that shows how food chains are linked together into more complex feeding relationshipsAdvantages over food chainShows much more complex interactions between species within a community/ecosystemMore than one producer supports a communityA single producer is a food source for many primary consumersA consumer might have a number of different food sources on the same/different trophic levelsA consumer can be an omnivore, feeding as a primary consumer but also as a consumer at higher tropic levels
10 5.1.6: Trophic levelThe tropic level of an organism defines the feeding relationship of that organism to other organisms in a food webAutotraphProducerTropic level 1HetertrophPrimary consumerTropic level 2Secondary consumerTrophic level 3heterotrophTertiary consumerTrophic level 4
11 5.1.7: Determining tropic levels in food chains/webs Assign tropic levels to the food web on the right!
12 5.1.8: Constructing a food web Producers are usually shown at the bottomUse full name of organismsArrows show the movement of matter & energy
13 5.1.9:Light & food chainsSunlight is the source of energy for most communities, both aquatic and terrestrialVery few communities deep in the ocean use geothermal energy
14 5.1.10: Energy flow in Food chain a) Not all solar energy will come into contact with chlorophyll and will therefore not be trapped in the synthesis of organic compoundsb) Photosynthesisc) Consumers feeding and passing on energy in the foodd) Loss of energy as heat from respiratione) death and the consumption of dead organisms by detritivores. Or as food not assimilated because of incomplete digestion.Energy Lossloss of energy in undigested food which will then be used by saprophytes/ decomposersloss of heat energy in the reactions of respirationultimately all energy will be lost has heat
15 5.1.11: Efficiency of energy transformations When energy is changed from one form into another, it is never 100% efficientApproximately only 10-20% of the energy on one trophic level will be assimilated at the next higher trophic level
16 5.1.12: Shape of energy pyramids A pyramid of energy is a graphical representation of the amount of energy of each trophic level in a food chainThe units are kJ/m2/yrThe narrowing shape illustrates the gradual loss of energy processing along the links of a food chain to higher trophic levels
17 5.1.13: Energy and matter in ecosystems Energy is NOT recycled through the ecosystemEnergy is constantly received from the sun and constantly radiates out in the form of light & heatMatter IS recycledThe process of recycling nutrients requires energy
18 5.1.14: DecomposersTwo main groups are detritivores (e.g. earthworms, dung beetles) and saprotrophs (e.g. fungi, bacteria)Decomposition is a complex process and serves many functions; formation of soil, recycling of nutrients, reduction of high energy carbon compoundsOrganic molecules are oxidized to release nitrogen in the form of nitrate, nitrite, and ammoniaOxidation of organic compounds provides energy for saprophyte but returns matter to abiotic environment