Energy Flow, Ecosystems and the Environment

Photosynthesis Overview and ATPSign up

understand the overall reaction of photosynthesis: light energy splits water, hydrogen is stored in glucose by combination with CO₂, and O₂ is released to the atmosphere · understand how photophosphorylation of ADP requires energy, and that hydrolysis of ATP provides an immediate supply of energy for biological processes

The Light-Dependent ReactionsSign up

understand the light-dependent reactions of photosynthesis: light excites electrons in chlorophyll; the role of these electrons in generating ATP, reducing NADP in cyclic and non-cyclic photophosphorylation, and producing O₂ via photolysis of water

The Light-Independent Reactions and the Calvin CycleSign up

understand the light-independent reactions as reduction of CO₂ using the products of the light-dependent reactions (carbon fixation in the Calvin cycle, roles of GP, GALP, RuBP and RUBISCO) · know that the products are simple sugars used by plants, animals and other organisms in respiration and the synthesis of polysaccharides, amino acids, proteins, lipids and nucleic acids

Chloroplasts, Pigments and ChromatographySign up

understand the structure of chloroplasts in relation to their role in photosynthesis · understand the terms absorption spectrum and action spectrum · understand how chloroplast pigments can be separated using chromatography and identified using R+f values · CORE PRACTICAL 10: investigate the effects of light intensity, light wavelength, temperature and CO₂ availability on the rate of photosynthesis using a suitable aquatic plant

Productivity and Trophic TransfersSign up

understand the relationship between gross primary productivity (GPP), net primary productivity (NPP) and plant respiration (R); calculate NPP · know how to calculate the efficiency of biomass and energy transfers between trophic levels

Populations, Communities, Niches and HabitatsSign up

understand the terms population, community, habitat and ecosystem · understand that the numbers and distribution of organisms in a habitat are controlled by biotic and abiotic factors · understand how the concept of niche accounts for distribution and abundance of organisms in a habitat · CORE PRACTICAL 11: study the ecology of a habitat using quadrats and transects; measure relevant abiotic factors

Succession and Climax CommunitiesSign up

understand the stages of succession from colonisation to the formation of a climax community

Evidence and Causes of Climate ChangeSign up

understand the different types of evidence for climate change and its causes, including records of CO₂ levels, temperature records, pollen in peat bogs and dendrochronology; recognise correlations vs causal relationships · understand the causes of anthropogenic climate change, including the role of greenhouse gases in the greenhouse effect · understand how knowledge of the carbon cycle can be applied to methods that reduce atmospheric CO₂ · understand that data can be extrapolated to make predictions used in models of future climate change, and that these models have limitations

Climate Change Effects on Organisms and Enzyme ActivitySign up

understand the effects of climate change (changing rainfall, seasonal cycles) on plants and animals (distribution, development, lifecycles) · understand the effect of temperature on the rate of enzyme activity and its impact on plants, animals and microorganisms, including Q₁₀ · CORE PRACTICAL 12: investigate the effects of temperature on the development of organisms (e.g. seedling growth or brine shrimp hatch rates), with ethical use of organisms

Evolution, Speciation and Conservation ResponsesSign up

understand how evolution (changes in allele frequency) can come about through gene mutation and natural selection · understand how isolation reduces gene flow between populations, leading to allopatric or sympatric speciation · understand how scientific conclusions on controversial issues (climate change actions, human contribution) can depend on who is reaching the conclusions · understand how reforestation and the use of sustainable resources (including biofuels) manage the conflict between human needs and conservation