HabitatThe environment in which a species normally lives

EcosystemA community & its abiotic environment

CommunityA group of populations living and interacting together in the same area.

PopulationGroup of organisms of the same species living within the same area at a particular time

NicheRole of an organism within its habitat

SpeciesA group of organisms that can interbreed and produce fertile offspring.

Abiotic FactorsNon living, physical factors affecting survival

Biotic FactorsLiving factors affecting survival

HeterotrophGains energy by consuming organic molecules from other organisms

AutotrophCreates its own energy from non-living resources

SaprotrophLives on or in decaying organic matter, uses extracellular enzymes to digest, consume & absorb decaying matter

DetritivoreIngests non-living organic matter before digestion

ConsumerIngests living/ recently killed organic matter

5.1.1Define species, habitat, population, community, ecosystem and ecology. 5.1.2Distinguish between autotroph and heterotroph.5.1.3Distinguish between consumers, detritivores and saprotrophs.5.1.4Describe what is meant by a food chain, giving three examples, each with at least three linkages (four organisms).Shows energy flow from one species to another

5.1.5Describe what is meant by a food web.Shows energy flow within an ecosystem

5.1.6Define trophic level.An organisms trophic level is its position in the food chain, e.g. producer, primary consumer, secondary consumer, tertiary consumer. 5.1.9State that light is the initial energy source for almost all communities5.1.11State that energy transformations are never 100% efficient.5.1.10Explain the energy flow in a food chain. 5.1.12Explain reasons for the shape of pyramids of energy.5.1.13Explain that energy enters and leaves ecosystems, but nutrients must be recycled.5.1.14State that saprotrophic bacteria and fungi (decomposers) recycle nutrients. Energy is lost, while nutrients are recycled Never 100% efficient energy lost through heat during cell respiration, faecal matter, tissue loss & death Energy is initially supplied by the sun flows through tropic levels Nutrients are recycled finite resource Nutrients go from environment organisms environment Saprophytes & fungi recycle nutrients

5.2.1Draw and label a diagram of the carbon cycle to show the processes involved.

5.2.3Explain the relationship between rises in concentrations of atmospheric carbon dioxide, methane and oxides of nitrogen and the enhanced greenhouse effect.

1. The incoming radiation from the sun is short wave ultraviolet and visible radiation.2. Some of this radiation is absorbed by the Earths atmosphere.3. Some of the radiation is reflected back into space by the Earths surface.4. The radiation which is reflected back into space is infrared radiation and has a longer wavelength.5. The greenhouse gases in the atmosphere absorb some of this infrared radiation and re-reflect it back towards the earth.6. This causes the green house effect and results in an increase in average mean temperatures on earth.7. A rise in greenhouse gases results in an increase of the green house effect which can be disastrous for the planet.Greenhouse gases include carbon dioxide, nitrous oxide, tropospheric ozone, water vapour, methane, chlorofluorocarbons (CFCs), and volatile organic molecules.Causes & Effects of the Greenhouse effectCauses Deforestation less photosynthesis occurs more carbon dioxide & less oxygen Combustion of fossil fuels carbon dioxide released into atmosphere Cattle Production Increased methane output Use of Chlorine FluorocarbonsEffects Glacial melt in the arctic rising sea levels Climate change some organisms unable to survive loss of biodiversity Extended iceless periods more time for saprotrophs to break down organic matter more CO2 Season changes Migratory behaviour changes Lowland flooding5.2.4Outline the precautionary principle.5.2.5Evaluate the precautionary principle as a justification for strong action in response to the threats posed by the enhanced greenhouse effectWhen an activity raises threats of harm, measures should be taken, regardless of whether a causal relationship has been confirmed.Applies to global warming consequences too catastrophic & widespread to be ignored. Strong evidence suggests global warming is evident.5.2.6Outline the consequences of a global temperature rise on arctic ecosystems. Loss of ice habitats extensive flooding of lowlands Increased decay of detritus by micro-organisms Loss of glacial habitat Change in biodiversity wider flora, appearance of small mammals & increase in associated parasites Increase in conifers boreal forests formed heat energy absorbed further glacial melt Increased predation by expanded vertebrate populations

5.3.2Draw and label a graph showing a sigmoid (S-shaped) population growth curve.5.3.3 Explain the reasons for the exponential growth phase, the plateau phase and the transitional phase between these two phases.

Lag PhaseIndividuals are few and widely dispersed, must adapt to conditions. Natality is slow population growth is slow.Exponential Growth PhasePopulation grows at its biotic potential. Growth is not limited by biotic factors Natality > MortalityTransitional PhaseGrowth slows as natality but natality > mortality. Biotic factors begin to affect survivalPlateau PhaseN + I = M + EPopulation size is maintained constant as the population reaches its carrying capacity (k). 5.3.4 List three factors that set limits to population increase.Abiotic Natural disasters e.g. earthquakes, flooding Air Water Light Wind Soil pH Temperature Salinity Humidity

Biotic Competition (food, space, breeding partners) Predation Symbiosis ( Mutualism & Parasitism) Disease/ Waste

5.3.1Outline how population size is affected by natality, immigration, mortality and emigration. Predator/ prey relationship producers prey predators prey prey predators producers Unpredictability of abiotic factors N , Population when N > M (or v.v.) Mobile members of population I Population when I > E (or v.v.)

5.5.1Outline the binomial system of nomenclature.

Homo sapiens Capitalised genus name, followed by species name, in italics or underlined (printed or handwritten).

5.5.2List seven levels in the hierarchy of taxa kingdom, phylum, class, order, family, genus and species - using an example from two different kingdoms for each level.

Modern Day Humans: Kingdom: AnimaliaPhylum: ChordataClass: MammaliaOrder: PrimatesFamily: HominidaeGenus: HomoSpecies: Sapiens

Strawberries:Kingdom: PlantaePhylum: MagnoliophytaClass: EudicotsOrder: RosalesFamily: RosaceaeGenus: RosoidiaeSpecies: ananassa5.5.3Distinguish between the following phyla of plants, using simple external recognition features: bryophyta, filicinophyta, coniferophyta and angiospermophyta.Bryophytes Non-vascular - no xylem/ phloem. No roots rhizoid instead. Simple leaves & stems Produce spores stored inside a capsule at the end of a stalkFilicinophytes Vascular. Non woody stems Pinnate leaves curled in a bud Spores are produced in sporangia, usually on the underside of the leaves.Angiosperms Vascular Flowers & fruit, seeds usually inside fruit Seeds are produced from ovules inside the ovaries - part of the flower. Fruits develop from the ovaries and disperse seeds.Coniferophyta Vascular Woody Needle leaves Produces cones with seeds inside, relies on wind5.5.4Distinguish between the following phyla of animals, using simple external recognition features: porifera, cnidaria, platyhelminthes, annelida, mollusca and arthropoda.Porifera No major structure cells arranged in sac-like distribution around a central gastric cavity. Attached to a surface. Mostly aquaticCnidaria Aquatic, radially symmetrical. Mouth but no anus Body cavity is a single hole. Body wall is an endoderm, mesoglea & ectoderm. Ectoderm has stinging cells, esp. on tentacles. Nerve net in mesoglea.Platyhelminthes Flat, unsegmented Tripoblastic organisation. No cavity in middle Mouth & gut but no anus. Flame cells for excretion. No circulatory system.Annelidia Bilaterally symmetrical Mouth & anus Segmented worms Closed circulatory system Cuticle of collagenMollusca Soft, flexible, show little segmentation Consists of a head, flattened muscular foot & a mantle covered by a shell. Gills/ lungs for gas exchange & well developed blood circulation. Mouth & anusArthropoda Segmented bodies Hard chitin exoskeleton with jointed limbs. Open blood circulation haemocoel cavity & tubular heart. Ventral nerve cord with nerves in each segment