iGCSE Biology Section 5 lesson 1

1. iGCSE Biology Section 5 lesson 1

2. Content Section 5 Uses of biological resources • Food production • Selective breeding • Genetic modification (genetic engineering) • Cloning

3. Content • Food production Lesson 1 a) Food production Crop plants 5.1 describe how glasshouses and polythene tunnels can be used to increase the yield of certain crops 5.2 understand the effects on crop yield of increased carbon dioxide and increased temperature in glasshouses 5.3 understand the use of fertiliser to increase crop yield 5.4 understand the reasons for pest control and the advantages and disadvantages of using pesticides and biological control with crop plants. Micro-organisms 5.5 understand the role of yeast in the production of beer 5.6 describe a simple experiment to investigate carbon dioxide production by yeast, in different conditions 5.7 understand the role of bacteria (Lactobacillus) in the production of yoghurt 5.8 interpret and label a diagram of an industrial fermenter and explain the need to provide suitable conditions in the fermenter, including aseptic precautions, nutrients, optimum temperature and pH, oxygenation and agitation, for the growth of micro-organisms. Fish farming 5.9 explain the methods which are used to farm large numbers of fish to provide a source of protein, including maintenance of water quality, control of intraspecific and interspecific predation, control of disease, removal of waste products, quality and frequency of feeding and the use of selective breeding.

4. new-universe.org Population Growth new-universe.org

5. Demand for food csiro.au

6. Increased Yield

7. Glasshouses, polytunnels Increased Yield

8. Glasshouses, polytunnels Increased CO2, temperature Increased Yield

9. Glasshouses, polytunnels Increased CO2, temperature Increased Yield Using fertiliser

10. Glasshouses, polytunnels Increased CO2, temperature Increased Yield Using fertiliser Pest control

11. Glasshouses, polytunnels Using glasshouses (or greenhouses, polytunnels), farmers can use their knowledge of factors affecting the rate of photosynthesis to increase yields

12. Glasshouses, polytunnels Using glasshouses (or greenhouses, polytunnels), farmers can use their knowledge of factors affecting the rate of photosynthesis to increase yields Artificial lighting, so photosynthesis continues beyond daylight hours, and higher than normal light intensities

13. Glasshouses, polytunnels Using glasshouses (or greenhouses, polytunnels), farmers can use their knowledge of factors affecting the rate of photosynthesis to increase yields Artificial lighting, so photosynthesis continues beyond daylight hours, and higher than normal light intensities Additional heating to ensure that photosynthesis continues at an increased rate

14. Glasshouses, polytunnels Using glasshouses (or greenhouses, polytunnels), farmers can use their knowledge of factors affecting the rate of photosynthesis to increase yields Artificial lighting, so photosynthesis continues beyond daylight hours, and higher than normal light intensities Additional heating to ensure that photosynthesis continues at an increased rate Rate of photosynthesis also increased by additional carbon dioxide released into the atmosphere

15. Glasshouses, polytunnels Using glasshouses (or greenhouses, polytunnels), farmers can use their knowledge of factors affecting the rate of photosynthesis to increase yields Cost of increased provision Increase in yield

16. Glasshouses, polytunnels Using glasshouses (or greenhouses, polytunnels), farmers can use their knowledge of factors affecting the rate of photosynthesis to increase yields Optimum growing conditions Cost of increased provision Increase in yield

17. Glasshouses, polytunnels Paraffin heater Using glasshouses (or greenhouses, polytunnels), farmers can use their knowledge of factors affecting the rate of photosynthesis to increase yields Optimum growing conditions Cost of increased provision Increase in yield

18. Glasshouses, polytunnels Increased light Paraffin heater Using glasshouses (or greenhouses, polytunnels), farmers can use their knowledge of factors affecting the rate of photosynthesis to increase yields Optimum growing conditions Cost of increased provision Increase in yield

19. Glasshouses, polytunnels Increased light Increased CO2 Paraffin heater Using glasshouses (or greenhouses, polytunnels), farmers can use their knowledge of factors affecting the rate of photosynthesis to increase yields Optimum growing conditions Cost of increased provision Increase in yield

20. Glasshouses, polytunnels Increased light Increased CO2 Increased temperature Paraffin heater Using glasshouses (or greenhouses, polytunnels), farmers can use their knowledge of factors affecting the rate of photosynthesis to increase yields Optimum growing conditions Cost of increased provision Increase in yield

21. Factors affecting photosynthesis • Temperature • CO2 concentration • Light intensity

22. Factors affecting photosynthesis Temperature Rate of photosynthesis Temperature

23. Factors affecting photosynthesis Temperature As temperature rises, so does the rate of P/S. Here temperature is limiting the rate. Rate of photosynthesis Temperature

24. Factors affecting photosynthesis Temperature Rate of photosynthesis As temperature approaches 45oC, enzymes start to denature and rate of P/S falls to zero Temperature

25. Factors affecting photosynthesis Carbon dioxide concentration As CO2 increases, so does the rate of P/S. At this point [CO2] is the limiting factor. Rate of photosynthesis CO2 concentration

26. Factors affecting photosynthesis Carbon dioxide concentration Rate of photosynthesis Increasing [CO2] has no further effect. The limiting factor must now be sunlight or temperature. CO2 concentration

27. Factors affecting photosynthesis Light Intensity As light intensity increases, so does the rate of P/S. At this point light intensity is the limiting factor. Rate of photosynthesis Light intensity

28. Factors affecting photosynthesis Light Intensity Rate of photosynthesis Increasing light intensity has no further effect. The limiting factor must now be [CO2] or temperature. Light intensity

29. Using fertiliser Fertilisers contain certain minerals such as nitrogen (N), potassium (K) and phosphorus (P) which help plants to grow.

30. Using fertiliser Fertilisers contain certain minerals such as nitrogen (N), potassium (K) and phosphorus (P) which help plants to grow. Crop production is increased by replacing essential elements used by a previous crop , or by boosting the levels of certain elements.

31. Using fertiliser Fertilisers contain certain minerals such as nitrogen (N), potassium (K) and phosphorus (P) which help plants to grow. Nitrogen in particular is needed to build plant proteins, so increasing growth.

32. Pest control “A pest is any animal or plant which has a harmful effect on humans, their food or their living conditions.”

33. Pest control “A pest is any animal or plant which has a harmful effect on humans, their food or their living conditions.” Direct damage, as caused by feeding insects which eat leaves, or burrow into stems, fruits or roots.

34. Pest control “A pest is any animal or plant which has a harmful effect on humans, their food or their living conditions.” Direct damage, as caused by feeding insects which eat leaves, or burrow into stems, fruits or roots. Indirect damage – insects transmit a bacterial, viral or fungal infection into a crop.

35. Pest control Pesticides Biological control A chemical which destroys agricultural pests.

36. Pest control Pesticides Biological control A chemical which destroys agricultural pests.

37. Pest control Pesticides Biological control A chemical which destroys agricultural pests.

38. Pest control Pesticides Biological control A chemical which destroys agricultural pests. The use of a pest’s natural enemies to control its population and spread.

39. Pest control Pesticides Biological control A chemical which destroys agricultural pests. The use of a pest’s natural enemies to control its population and spread.

40. Pest control Pesticides Biological control A chemical which destroys agricultural pests. The use of a pest’s natural enemies to control its population and spread.

41. Pest control Pesticides Biological control A chemical which destroys agricultural pests. The use of a pest’s natural enemies to control its population and spread.

42. Pest control Pesticides Biological control A chemical which destroys agricultural pests. The use of a pest’s natural enemies to control its population and spread.

43. Micro-organisms and food production

44. Micro-organisms and food production Beer, yeast and fermentation

45. Micro-organisms and food production Beer, yeast and fermentation

46. Micro-organisms and food production Made from barley Beer, yeast and fermentation

47. Micro-organisms and food production Made from barley Beer, yeast and fermentation Barley grains soaked for 2 days in water at room temperature – then allowed to germinate for a further four days, and enzymes are activated.

48. Micro-organisms and food production Made from barley Beer, yeast and fermentation Barley grains soaked for 2 days in water at room temperature – then allowed to germinate for a further four days, and enzymes are activated. Grains are dried and crushed, mixed with water at 65oC and extra starch added.

49. Micro-organisms and food production Made from barley Beer, yeast and fermentation Barley grains soaked for 2 days in water at room temperature – then allowed to germinate for a further four days, and enzymes are activated. Enzymes digest starch. Sugary solution then boiled with hops ( wort) Grains are dried and crushed, mixed with water at 65oC and extra starch added.

50. Micro-organisms and food production Yeast is added to the wort Beer, yeast and fermentation