Photosynthesis, Food Production and Management of the Environment

What Photosynthesis, Food Production and Management of the Environment covers

Photosynthesis, Food Production and Management of the Environment is examined in all three written papers — the specification states that Components 01, 02 and 03 can each assess content from any of the five modules, so nothing is confined to one paper. It covers chloroplast ultrastructure and photosynthetic pigments, the light-dependent stage of photosynthesis, the Calvin cycle, investigating the factors affecting photosynthesis, the Hill reaction and DCPIP, using TP and GP to build carbohydrates, lipids and amino acids, the compensation point and crop production, microorganisms, the nitrogen cycle and biosensors, biomass transfer and efficiency in food production, ruminants in the human food chain, farms as ecosystems and the conflict with conservation and deflected succession and measuring biodiversity.

The 12 subtopics

Each one has its own page.

• Chloroplast ultrastructure and photosynthetic pigmentsRecall questions on the chloroplast envelope, thylakoids, grana, stroma and intergranal lamellae, where the light-dependent components and RuBisCO sit, chloroplast DNA and ribosomes, and separating chlorophyll a, chlorophyll b, carotene and xanthophyll by paper chromatography with Rf values.Open →
• The light-dependent stage of photosynthesisRecall questions on where the light-dependent stage happens, light harvesting complexes and photoactivation, the electron transport chain and proton gradient, photophosphorylation by ATP synthase, the photolysis of water, NADP as final electron acceptor, and the effects of darkness and herbicides.Open →
• The Calvin cycleRecall questions on the site of the cycle, the fixation step and its enzyme, what the light-dependent stage supplies, turns per glucose, and the effect of sudden darkness.Open →
• Investigating the factors affecting photosynthesisRecall questions on measuring oxygen release, why hydrogencarbonate is added, how lamp distance changes intensity, wavelength and temperature effects, and why readings wait after a change in conditions.Open →
• The Hill reaction and DCPIPRecall questions on what isolated chloroplasts demonstrated, the dye's colour change, why the extraction medium is ice-cold, isotonic and buffered, and the controls a valid experiment needs.Open →
• Using TP and GP to build carbohydrates, lipids and amino acidsRecall questions on turning triose phosphate into hexose, starch, sucrose, cellulose and triglycerides, building amino acids from GP with nitrate and sulfate, nitrate deficiency, and why plant respiration and animal nutrition both depend on photosynthesis.Open →
• The compensation point and crop productionRecall questions on the compensation point and compensation period, shade and sun plants, reading net carbon dioxide uptake graphs, crop spacing and glasshouse lighting, and using hydrogencarbonate indicator, with controls and a water bath, to compare compensation points.Open →
• Microorganisms, the nitrogen cycle and biosensorsRecall questions on nitrogen fixation by Azotobacter and Rhizobium, nitrogenase and leghaemoglobin, nitrification by Nitrosomonas and Nitrobacter, ammonification, legumes in crop rotation, culturing Rhizobium aseptically from root nodules, and luminescent bacteria as biosensors of water toxicity.Open →
• Biomass transfer and efficiency in food productionRecall questions on biomass and dry mass, calculating the efficiency of biomass transfer, why biomass is lost between trophic levels, the length of food chains, farmed fish compared with beef cattle, the sustainability of salmon farming, feeding maize to cattle, and rearing livestock indoors.Open →
• Ruminants in the human food chainRecall questions on the rumen, reticulum, omasum and abomasum, rumination and chewing the cud, how rumen microorganisms digest cellulose and supply volatile fatty acids and protein, the carbon dioxide and methane they produce, the mutualism, and the value and environmental cost of ruminants as food.Open →
• Farms as ecosystems and the conflict with conservationRecall questions on the biotic and abiotic factors a farmer manages, why a monoculture is unstable, intensive and extensive farming, hedgerow removal, eutrophication from nitrate, persistent pesticides, slurry and safe disposal of farm waste, and the Countryside Stewardship scheme.Open →
• Deflected succession and measuring biodiversityRecall questions on succession, pioneer species and climax communities, primary and secondary succession, deflected succession and the plagioclimax maintained by grazing, forestry and ploughing, and sampling with random quadrats and line or belt transects, frequency, percentage cover and species-area curves.Open →

What you need to know

Answer each one before you reveal it.

Take Photosynthesis, Food Production and Management of the Environment further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

• Light-dependent stage vs Light-independent stage

  Light-dependent stage: the stage in the thylakoid membranes that uses absorbed light to make ATP and reduced NADP, releasing oxygen from water. Light-independent stage: the stage in the stroma that spends ATP and reduced NADP on fixing carbon dioxide into sugars.

• GP vs TP

  GP: the first three-carbon compound formed when carbon dioxide joins RuBP, which is then reduced using ATP and reduced NADP. TP: the reduced three-carbon sugar that is the output of the cycle, most of it being used to regenerate the five-carbon acceptor.

• Compensation point vs Compensation period

  Compensation point: the light intensity at which a plant's rate of photosynthesis exactly equals its rate of respiration, so there is no net gas exchange. Compensation period: the time taken after dawn for a plant to make up by photosynthesis the respiration it carried out overnight.

Questions from this topic

Each one with the model answer underneath.

1. 1

   What type of membrane encloses a chloroplast?

   Model answer

   A double membrane called the chloroplast envelope, made of an inner and an outer membrane separated by a narrow intermembrane space.

2. 2

   Name the flattened membrane sacs inside a chloroplast and the stacks they form.

   Model answer

   The flattened sacs are thylakoids, and a stack of thylakoids is called a granum.

3. 3

   What is the stroma of a chloroplast?

   Model answer

   The stroma is the fluid-filled matrix surrounding the grana, in which the enzymes of the light-independent reactions are dissolved.

4. 4

   Which four components of the light-dependent reaction are held in the thylakoid membranes?

   Model answer

   The light harvesting complexes, the photosystems, the electron transport chain and ATP synthase.

5. 5

   Where in the chloroplast is RuBisCO found, and why is that where it is needed?

   Model answer

   RuBisCO is dissolved in the stroma, because the Calvin cycle reactions it catalyses take place there.

6. 6

   Explain the advantage of the thylakoid membranes being arranged in stacks.

   Model answer

   Stacking packs a very large membrane surface area into a small volume, so many more light harvesting complexes and photosystems can be held for absorbing light.

What is inside Levo

Six ways to work the same material.

Photosynthesis, Food Production and Management of the Environment revision questions

What does Photosynthesis, Food Production and Management of the Environment cover in OCR A-Level Biology B?

12 subtopics: chloroplast ultrastructure and photosynthetic pigments, the light-dependent stage of photosynthesis, the calvin cycle, investigating the factors affecting photosynthesis, the hill reaction and dcpip, using tp and gp to build carbohydrates, lipids and amino acids, the compensation point and crop production, microorganisms, the nitrogen cycle and biosensors, biomass transfer and efficiency in food production, ruminants in the human food chain, farms as ecosystems and the conflict with conservation and deflected succession and measuring biodiversity. Each one has its own page with questions and model answers.

How is Photosynthesis, Food Production and Management of the Environment organised?

By the OCR H422 specification, subtopic by subtopic, so it matches the order you are taught it in.