KA 5: Food Production

• What is the relationship between the increasing human population and food yield?

  Increasing human population requires an increased food yield.
• How do fertilisers contribute to crop yield?

  Fertilisers provide chemicals such as nitrates which increase crop yield.
• What role do pesticides play in agriculture?

  Pesticides can kill plants and animals that reduce crop yield.
• What happens to nitrates dissolved in soil water?

  Nitrates dissolved in soil water are absorbed into plants.
• What do plants use nitrates for?

  Plants use nitrates to produce amino acids which are synthesised into plant proteins.
• How do animals obtain amino acids for protein synthesis?

  Animals consume plants or other animals to obtain amino acids for protein synthesis.
• How can fertilisers affect soil nitrate content?

  Fertilisers can be added to soil to increase the nitrate content of the soil.
• What is a potential environmental issue caused by fertilisers?

  Fertilisers can leach into fresh water, adding extra, unwanted nitrates.
• What is the consequence of increased nitrates in water bodies?

  Increased nitrates can lead to algal blooms.
• How do algal blooms affect aquatic plants?

  Algal blooms reduce light levels, killing aquatic plants.
• What happens to dead plants and algae in water bodies?

  Dead plants and algae become food for bacteria which increase greatly in number.
• What is the effect of bacteria on oxygen levels in water bodies?

  Bacteria use up large quantities of oxygen, reducing the oxygen availability for other organisms.
• How can genetically modified (GM) crops help in agriculture?

  Genetically modified (GM) crops can be used to reduce the use of fertilisers.
• What are two investigations related to fertilisers mentioned in the study material?

  1. Investigate the effect of fertilisers on plant growth.
  2. Investigate the effect of fertiliser concentration on algal growth.
• What is a potential risk of pesticide use in agriculture?

  Pesticides sprayed onto crops can accumulate in the bodies of organisms over time.
• What happens to pesticide toxicity as it is passed along food chains?

  As pesticides are passed along food chains, toxicity increases and can reach lethal levels.
• What are two alternatives to the use of pesticides in agriculture?

  The use of biological control and genetically modified (GM) crops are alternatives to pesticides.
• What is the primary reason for the increased food yield due to the growing human population?

  It requires an increased food yield.
• How do fertilisers contribute to crop yield?

  Fertilisers provide chemicals such as nitrates which increase crop yield.
• What role do pesticides play in agriculture?

  Pesticides can kill plants and animals that reduce crop yield.
• What happens to nitrates dissolved in soil water?

  Nitrates are absorbed into plants.
• How are amino acids produced in plants?

  Nitrates are used to produce amino acids which are synthesised into plant proteins.
• How do animals obtain amino acids for protein synthesis?

  Animals consume plants or other animals to obtain amino acids for protein synthesis.
• What can be done to increase the nitrate content of the soil?

  Fertilisers can be added to soil to increase the nitrate content.
• What is a potential environmental issue caused by fertilisers?

  Fertilisers can leach into fresh water, adding extra, unwanted nitrates.
• What is the consequence of increased nitrates in fresh water?

  It will increase algal populations which can cause algal blooms.
• What effect do algal blooms have on aquatic plants?

  Algal blooms reduce light levels, killing aquatic plants.
• What happens to dead plants and algae after they die?

  They become food for bacteria which increase greatly in number.
• What is the impact of bacteria on oxygen levels in water?

  Bacteria use up large quantities of oxygen, reducing the oxygen availability for other organisms.
• How can genetically modified (GM) crops help in agriculture?

  GM crops can be used to reduce the use of fertilisers.
• What is a potential risk of using pesticides in agriculture?

  Pesticides sprayed onto crops can accumulate in the bodies of organisms over time.
• What happens to pesticide toxicity as it is passed along food chains?

  Toxicity increases and can reach lethal levels.
• What are two alternatives to chemical pesticides?

  The use of biological control and genetically modified (GM) crops.
• Genetically modifying (GM) crops involves introducing a new trait to a plant, which does not occur naturally in this species e.g. resistance to certain pests or diseases or improved nutritional value (golden rice).
• Biological control and GM crops may be alternatives to lessen the effects of intensive farming on the environment.
• Biological control is a method of controlling crop pests by using other organisms, which can be used to increase crop yields. It can involve the use of predators or parasites or bacteria/fungi.