1. IGCSE BIOLOGY SECTION 5 LESSON 1

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

3. Content 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

8. Increased Yield Glasshouses, polytunnels Increased CO 2, temperature

9. Increased Yield Glasshouses, polytunnels Increased CO 2, temperature Using fertiliser

10. Increased Yield Glasshouses, polytunnels Increased CO 2, temperature 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 Cost of increased provision Increase in yield Optimum growing conditions

17. 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 Optimum growing conditions Paraffin heater

18. 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 Optimum growing conditions Paraffin heater Increased light

19. 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 Optimum growing conditions Paraffin heater Increased light Increased CO 2

20. 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 Optimum growing conditions Paraffin heater Increased light Increased CO 2 Increased temperature

21. Factors affecting photosynthesis 1.Temperature 2.CO 2 concentration 3.Light intensity

22. Factors affecting photosynthesis Temperature Rate of photosynthesis Temperature

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

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

25. Factors affecting photosynthesis Carbon dioxide concentration Rate of photosynthesis CO 2 concentration As CO 2 increases, so does the rate of P/S. At this point [CO 2 ] is the limiting factor.

26. Factors affecting photosynthesis Carbon dioxide concentration Rate of photosynthesis CO 2 concentration Increasing [CO 2 ] has no further effect. The limiting factor must now be sunlight or temperature.

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

28. Factors affecting photosynthesis Light Intensity Rate of photosynthesis Light intensity Increasing light intensity has no further effect. The limiting factor must now be [CO 2 ] or temperature.

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. PesticideKills InsecticideInsects FungicideParasitic fungi Herbicide‘weed’ plants

37. Pest control Pesticides Biological control A chemical which destroys agricultural pests. AdvantagesDisadvantages Easily applied Can affect human health Very effectiveKills wildlife Quick resultsPollution Can be economical Can enter the food chain

38. Pest control Pesticides Biological control A chemical which destroys agricultural pests. AdvantagesDisadvantages Easily applied Can affect human health Very effectiveKills wildlife Quick resultsPollution Can be economical Can enter the food chain 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. AdvantagesDisadvantages Easily applied Can affect human health Very effectiveKills wildlife Quick resultsPollution Can be economical Can enter the food chain The use of a pest’s natural enemies to control its population and spread. Example 1: Coconut moth – In Fiji, these pests were brought under control by introducing the fly Ptychomyia remota, a natural predator from Malaysia

40. Pest control Pesticides Biological control A chemical which destroys agricultural pests. AdvantagesDisadvantages Easily applied Can affect human health Very effectiveKills wildlife Quick resultsPollution Can be economical Can enter the food chain The use of a pest’s natural enemies to control its population and spread. Example 2: Winter moths. – in Canada these insects are pests of forests and shade trees. They have been controlled by a tachinid fly and an ichneumonid wasp.

41. Pest control Pesticides Biological control A chemical which destroys agricultural pests. AdvantagesDisadvantages Easily applied Can affect human health Very effectiveKills wildlife Quick resultsPollution Can be economical Can enter the food chain The use of a pest’s natural enemies to control its population and spread. Example 3: Prickly pear. – a widespread invasive species in Australia. The moth Cactoblastis cactorum from South America, introduced in 1925, almost wiped out the population.

42. Pest control Pesticides Biological control A chemical which destroys agricultural pests. AdvantagesDisadvantages Easily applied Can affect human health Very effectiveKills wildlife Quick resultsPollution Can be economical Can enter the food chain The use of a pest’s natural enemies to control its population and spread. AdvantagesDisadvantages Pest-specific Biological control species may feed on beneficial organisms Inexpensive (once introduced) Control species can sustain themselves Initial costs Does not eliminate all pest population

43. Micro-organisms and food production

44. Beer, yeast and fermentation

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

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

47. Micro-organisms and food production Beer, yeast and fermentation Made from barley 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 Beer, yeast and fermentation Made from barley 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 65 o C and extra starch added.

49. Micro-organisms and food production Beer, yeast and fermentation Made from barley 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 65 o C and extra starch added. Enzymes digest starch. Sugary solution then boiled with hops (  wort)

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

51. Micro-organisms and food production Beer, yeast and fermentation Yeast is added to the wort Yeast respiration initially aerobic, but eventually anaerobic respiration takes over and alcohol is produced.

52. Micro-organisms and food production Beer, yeast and fermentation Yeast is added to the wort Yeast respiration initially aerobic, but eventually anaerobic respiration takes over and alcohol is produced. Fermentation takes 5 – 14 days, producing an alcohol content of between 3 and 5%

53. Micro-organisms and food production Beer, yeast and fermentation Yeast is added to the wort Yeast respiration initially aerobic, but eventually anaerobic respiration takes over and alcohol is produced. Fermentation takes 5 – 14 days, producing an alcohol content of between 3 and 5% Dead yeast, proteins and hop resins are allowed to settle, leaving behind the final product.

54. Micro-organisms and food production Beer, yeast and fermentation Yeast is added to the wort Yeast respiration initially aerobic, but eventually anaerobic respiration takes over and alcohol is produced. Fermentation takes 5 – 14 days, producing an alcohol content of between 3 and 5% Dead yeast, proteins and hop resins are allowed to settle, leaving behind the final product. Cheers!

55. describe a simple experiment to investigate carbon dioxide production by yeast, in different conditions

56. Liquid paraffin Glucose solution and yeast

57. describe a simple experiment to investigate carbon dioxide production by yeast, in different conditions Temperature of water bath ( o C) Volume of carbon dioxide produced (cm 3 ) 155 2510 3521 4536 5512 653

58. describe a simple experiment to investigate carbon dioxide production by yeast, in different conditions Temperature of water bath ( o C) 15 25 35 45 55 65 40 30 20 10 0 Volume of carbon dioxide produced (cm 3 ) X X X X X X

59. describe a simple experiment to investigate carbon dioxide production by yeast, in different conditions Temperature of water bath ( o C) 15 25 35 45 55 65 40 30 20 10 0 Volume of carbon dioxide produced (cm 3 ) X X X X X X The rate of carbon dioxide production increases to a temperature of about 45 o C and then decreases as enzymes are denatured by exposure to higher temperatures.

60. Making yoghurt!

61. Making Yoghurt Lactobacillus

62. Making Yoghurt Lactobacillus 1. Milk (from cows, sheep or goats) is homogenized – fat droplets are broken up to stop them separating out

63. Making Yoghurt Lactobacillus 1. Milk (from cows, sheep or goats) is homogenized – fat droplets are broken up to stop them separating out 2. Milk is then pasteurized to destroy harmful bacteria and other micro-organisms

64. Making Yoghurt Lactobacillus 1. Milk (from cows, sheep or goats) is homogenized – fat droplets are broken up to stop them separating out 2. Milk is then pasteurized to destroy harmful bacteria and other micro-organisms 3. Pasteurized milk is then fermented by adding a ‘starter culture’ of bacteria (eg. Lactobacillus).

65. Making Yoghurt Lactobacillus 1. Milk (from cows, sheep or goats) is homogenized – fat droplets are broken up to stop them separating out 2. Milk is then pasteurized to destroy harmful bacteria and other micro-organisms 3. Pasteurized milk is then fermented by adding a ‘starter culture’ of bacteria (eg. Lactobacillus). 4. Bacteria act on the milk sugar, lactose, and convert it to lactic acid which coagulates milk protein (casein).

66. Making Yoghurt Lactobacillus 1. Milk (from cows, sheep or goats) is homogenized – fat droplets are broken up to stop them separating out 2. Milk is then pasteurized to destroy harmful bacteria and other micro-organisms 3. Pasteurized milk is then fermented by adding a ‘starter culture’ of bacteria (eg. Lactobacillus). 4. Bacteria act on the milk sugar, lactose, and convert it to lactic acid which coagulates milk protein (casein). 5. Thickening produces the creamy yoghurt consistency.

67. Making Yoghurt Lactobacillus 1. Milk (from cows, sheep or goats) is homogenized – fat droplets are broken up to stop them separating out 2. Milk is then pasteurized to destroy harmful bacteria and other micro-organisms 3. Pasteurized milk is then fermented by adding a ‘starter culture’ of bacteria (eg. Lactobacillus). 4. Bacteria act on the milk sugar, lactose, and convert it to lactic acid which coagulates milk protein (casein). 5. Thickening produces the creamy yoghurt consistency. 6. Conditions: fermentation works best at temperature of 46 o C and yoghurt formed is cooled to 5 o C to stop the bacterial process. Lactic acid gives yoghurt a sour taste.

68. Making Yoghurt Lactobacillus 1. Milk (from cows, sheep or goats) is homogenized – fat droplets are broken up to stop them separating out 2. Milk is then pasteurized to destroy harmful bacteria and other micro-organisms 3. Pasteurized milk is then fermented by adding a ‘starter culture’ of bacteria (eg. Lactobacillus). 4. Bacteria act on the milk sugar, lactose, and convert it to lactic acid which coagulates milk protein (casein). 5. Thickening produces the creamy yoghurt consistency. 6. Conditions: fermentation works best at temperature of 46 o C and yoghurt formed is cooled to 5 o C to stop the bacterial process. Lactic acid gives yoghurt a sour taste. Throughout the process the materials and containers must be kept in sterile conditions to prevent competition from other micro- organisms

69. Industrial fermentation

70. www.biologymad.com

71. Industrial fermentation www.biologymad.com Growing micro-organisms on a large scale.

72. Industrial fermentation www.biologymad.com Growing micro-organisms on a large scale. Stainless Steel vessel

73. Industrial fermentation www.biologymad.com Growing micro-organisms on a large scale. Stainless Steel vessel Nutrients added for optimum microbe growth

74. Industrial fermentation www.biologymad.com Growing micro-organisms on a large scale. Stainless Steel vessel Nutrients added for optimum microbe growth Agitates the contents

75. Industrial fermentation www.biologymad.com Growing micro-organisms on a large scale. Stainless Steel vessel Nutrients added for optimum microbe growth Agitates the contents If microbes are aerobic, oxygen must be added

76. Industrial fermentation www.biologymad.com Growing micro-organisms on a large scale. Stainless Steel vessel Nutrients added for optimum microbe growth Agitates the contents If microbes are aerobic, oxygen must be added Temperature and pH must be constantly monitored Fermentation gives off a lot of heat, so a cooling jacket is required

77. Industrial fermentation www.biologymad.com Growing micro-organisms on a large scale. Stainless Steel vessel Nutrients added for optimum microbe growth Agitates the contents If microbes are aerobic, oxygen must be added Temperature and pH must be constantly monitored Fermentation gives off a lot of heat, so a cooling jacket is required The vessel, nutrients and air supply are all sterilised beforehand to prevent any possibility of unwanted micro-organisms getting into the mixture

78. Fish Farming Production of large numbers of fish (very good source of protein)

79. Fish Farming Production of large numbers of fish (very good source of protein)

80. Fish Farming Production of large numbers of fish (very good source of protein)

81. Fish Farming Production of large numbers of fish (very good source of protein)

82. Features of fish farming Fish Farming

83. Features of fish farming Fish kept in nets or tanks  keeps predators (seals, birds) out. Keeps fish together and limits movement. Fish Farming

84. Features of fish farming Fish kept in nets or tanks  keeps predators (seals, birds) out. Keeps fish together and limits movement. Fish fed on a special diet so they maximise energy transfer, and create minimum amount of faeces (so less eutrophication) Fish Farming

85. Features of fish farming Fish kept in nets or tanks  keeps predators (seals, birds) out. Keeps fish together and limits movement. Fish fed on a special diet so they maximise energy transfer, and create minimum amount of faeces (so less eutrophication) Fish Farming Eggs artifically fertilized, young raised in special tanks (avoid predators and bigger fish). Controlled conditions, growth hormones.

86. Features of fish farming Fish kept in nets or tanks  keeps predators (seals, birds) out. Keeps fish together and limits movement. Fish fed on a special diet so they maximise energy transfer, and create minimum amount of faeces (so less eutrophication) Fish Farming Eggs artifically fertilized, young raised in special tanks (avoid predators and bigger fish). Controlled conditions, growth hormones. Crowding means that danger of disease and parasites is high. Chemicals added to control parasites. Antibiotics control spread of disease.

87. Features of fish farming Fish kept in nets or tanks  keeps predators (seals, birds) out. Keeps fish together and limits movement. Fish fed on a special diet so they maximise energy transfer, and create minimum amount of faeces (so less eutrophication) Fish Farming Eggs artifically fertilized, young raised in special tanks (avoid predators and bigger fish). Controlled conditions, growth hormones. Crowding means that danger of disease and parasites is high. Chemicals added to control parasites. Antibiotics control spread of disease. Biological control also used. A fish called wrasse eats lice off the salmon. Fungicides also used to prevent fungal infections.

88. Features of fish farming Fish kept in nets or tanks  keeps predators (seals, birds) out. Keeps fish together and limits movement. Fish fed on a special diet so they maximise energy transfer, and create minimum amount of faeces (so less eutrophication) Fish Farming Eggs artifically fertilized, young raised in special tanks (avoid predators and bigger fish). Controlled conditions, growth hormones. Crowding means that danger of disease and parasites is high. Chemicals added to control parasites. Antibiotics control spread of disease. Biological control also used. A fish called wrasse eats lice off the salmon. Fungicides also used to prevent fungal infections. Water quality maintained by constant monitoring.

89. Features of fish farming Fish kept in nets or tanks  keeps predators (seals, birds) out. Keeps fish together and limits movement. Fish fed on a special diet so they maximise energy transfer, and create minimum amount of faeces (so less eutrophication) Fish Farming Eggs artifically fertilized, young raised in special tanks (avoid predators and bigger fish). Controlled conditions, growth hormones. Crowding means that danger of disease and parasites is high. Chemicals added to control parasites. Antibiotics control spread of disease. Biological control also used. A fish called wrasse eats lice off the salmon. Fungicides also used to prevent fungal infections. Water quality maintained by constant monitoring. Waste products removed.

90. Features of fish farming Fish kept in nets or tanks  keeps predators (seals, birds) out. Keeps fish together and limits movement. Fish fed on a special diet so they maximise energy transfer, and create minimum amount of faeces (so less eutrophication) Fish Farming Eggs artifically fertilized, young raised in special tanks (avoid predators and bigger fish). Controlled conditions, growth hormones. Crowding means that danger of disease and parasites is high. Chemicals added to control parasites. Antibiotics control spread of disease. Biological control also used. A fish called wrasse eats lice off the salmon. Fungicides also used to prevent fungal infections. Water quality maintained by constant monitoring. Waste products removed. Selective breeding

91. End of Section 5 Lesson 1 In this lesson we have covered: Population growth and demand for food Increasing food production Micro-organisms and food production Fish farming