(i) the ultrastructure of the chloroplast

To include the location of the components for the light-dependent reaction in the thylakoid membranes (light harvesting complexes, photosystems, electron transport chain and ATP synthase) and the location of the enzymes for the light-independent reactions in the stroma.

(ii) practical investigation into the separation of pigments by paper chromatography

No details of the structure of carotenoids or accessory pigments are required.
PAG6

the process of the light-dependent stage of photosynthesis

To include the transfer of light energy to chemical energy in the form of ATP and reduced NADP (details of cyclic and non-cyclic photophosphorylation are not required).

the production of complex organic molecules in the light-independent stage of photosynthesis (Calvin cycle)

To include the use of the products of the light-dependent reactions (ATP and reduced NADP) within the light-independent reactions AND the role of carbon dioxide, ribulose bisphosphate carboxylase (RuBisCO), ribulose bisphosphate (RuBP), glycerate-3-phosphate (GP) and triose phosphate (TP) but no other biochemical detail is required.

(i) practical investigations into the factors affecting photosynthesis

To include light wavelength, light intensity, light duration, temperature and pH.
PAG4

(ii) practical investigations of the Hill Reaction (light dependent reaction) using DCPIP

PAG4

the metabolism of TP and GP to produce carbohydrates, lipids and amino acids

To include reference to the need for appropriate mineral ions (e.g. nitrates and sulfates in relation to amino acids).

the dependency of respiration in plants and animals upon the products of photosynthesis

(i) the biological significance of the compensation point for crop production

(ii) an interpretation of data and graphs relating to the biological significance of the compensation point for crop production

(iii) practical investigation of different leaf samples to compare compensation points with hydrogencarbonate indicator solution

(i) the importance of microorganisms in maintaining ecosystems, with reference to the nitrogen cycle

To include the recycling of nitrogen by bacteria, with reference to the roles of Azotobacter, Nitrosomonas, Nitrobacter and Rhizobium AND the use of luminescent microorganisms as biosensors in environmental monitoring.

(ii) culturing of Rhizobium spp. in vitro

PAG1

(iii) investigating the appearance of root nodules in legumes

the transfer of biomass through a food chain in food production

a consideration of the efficiency of biomass transfers in the food chain with reference to their comparative ability to provide resources in a sustainable fashion

To include fish farming and maize grown as animal feed for beef cattle reared for human consumption.

\(\text{efficiency} = \dfrac{\text{biomass transferred}}{\text{biomass intake}} × 100\)

the role of ruminants in the human food chain

To include an outline of the structure and composition of the ruminant digestive system as an ecosystem and the role of microorganisms within this ecosystem in the digestion of cellulose, the production of fatty acids and as a source of protein.

(i) farms as ecosystems

(ii) the potential for conflict between agriculture and conservation

To include a consideration of farms as ecosystems where biotic and abiotic factors impact on productivity AND the features of intensive and extensive farming to include the advantages and disadvantages with reference to hedgerow removal, use of chemicals, disposal of farm waste and consideration of government schemes such as the countryside stewardship scheme.

(i) how land management can result in deflected succession

To include descriptions of succession as a dynamic process moving from colonisation to climax communities AND how examples of land management practices (to include forestry and agriculture) can deflect succession.

(ii) practical investigations of differences in biodiversity using techniques such as random and systematic sampling

PAG3