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Producers (autotrophs) make their own food by photosynthesis
6CO2 + 6H20 602 + CH12O6
(in the presence of light and chlorophyll)
Photolysis is used, the process of splitting water using light energy
Photosynthesis stores energy as glucose

Photosynthesis occurs in the chloroplasts (small, flattened…

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7) As well as two hydrogen ions being taken from the water, two electrons are taken to
replace those from the chlorophyll. The electron transport chain splits water
(photolysis) using energy from sunlight.
8) The oxygen from the water is released through the leaf (waste product).


dependent reactions include…

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Chlorophyll a excited and promotes electron to higher energy level
e- picked up by electron carrier
Enough energy released to photophosphorylate
Electrons aren't passed on to NADP, but are passed back into photosystem I via
electron carriers ­ electrons repeatedly flow through PSI (recycled).

In the stroma…

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Photolysis: Splitting of a molecule using light
Hydrolysis: Splitting of a molecule using water (ATP hydrolysed to ADP)
Redox reactions: Involve oxidation (losing electrons) and reduction (gaining

Chloroplasts are adapted for photosynthesis because thylakoids have a large surface area so
more light can be absorbed. Stroma contains the enzymes…

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Parasitism ­ diseased animals will be weakened and not reproduce
successfully. They cannot hunt well and are more likely to be caught. Parasites
can wipe out whole populations and spread fast when there is a high
population (close proximity).
Competition for resources

Anthropogenic factors arise from human activity and…

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NPP (Net Primary Productivity) is the rate that organic molecules are made into new
biomass. NPP = GPP ­ R
% efficiency of energy transfer between trophic levels = (NPP of a level/NPP of previous
level) x 100
Energy transfer is not efficient:
Not all of the available food gets…

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Other factors of climate change are:
Degree of reflection from ice and snow
Extent of cloud cover
Changes in sun's radiation
Extrapolation = extending a line on a graph ­ we assume there is enough data to establish
the trend accurately and present trends continue. Extrapolation is often the basis…

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Biofuels ­ fuels directly from biomass which are burnt to release energy,
producing carbon dioxide. Because the amount of carbon dioxide released
when burnt is the same removed by photosynthesis, plants are carbon
neutral so have no net increase. Plants can be grown all the time so are a

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Hybrid inviability: Hybrids produced but don't live long enough to reproduce
Hybrid sterilisation: Hybrid survives long enough to breed but is infertile

In order to test theories, data needs to be collected to prove or disprove it. Scientists
within the scientific community accept evolution as there is evidence…




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