Food Production

• What are glasshouses and polythene tunnels used for in agriculture?

  To increase the yield of certain crops
• How can knowledge about limiting factors improve crop yields?

  It helps farmers understand how factors affect the rate of photosynthesis
• What is a limitation of growing crops outside?

  Farmers cannot control environmental factors
• What advantage do glasshouses and polythene tunnels provide to farmers?

  They allow some control over the climate to increase crop yields
• What conditions can be manipulated in a glasshouse to increase photosynthesis?

  Artificial heating, lighting, carbon dioxide content, and regular watering
• Why is artificial heating used in glasshouses?

  To help enzymes controlling photosynthesis work faster
• In which countries is artificial heating in glasshouses primarily used?

  Temperate countries such as the UK
• What must be done in tropical countries when using glasshouses?

  They may need to be ventilated to release hot air
• What are polythene tunnels commonly used for?

  To protect crops from weather effects and increase temperature
• How do polythene tunnels help with pest control?

  They prevent the entry of pests and diseases
• What limits the rate of photosynthesis in plants?

  The lowest supply of light, carbon dioxide, or temperature
• What happens to the rate of photosynthesis as temperature increases?

  The rate increases until enzymes begin to denature
• How does light intensity affect photosynthesis?

  More light increases the rate until another factor becomes limiting
• What is the role of carbon dioxide in photosynthesis?

  It is a raw material that increases the reaction rate
• Why do plants need fertilizers?

  To replace mineral ions taken up from the soil
• What are the two forms of fertilizers?

  Organic fertilizers and chemical fertilizers
• What is nitrogen needed for in plants?

  To make amino acids, the building blocks of proteins
• What are the effects of a lack of nitrogen in plants?

  Weak growth and yellowing of leaves
• What is phosphorus needed for in plants?

  To make DNA and cell membranes
• What are the effects of a lack of phosphorus in plants?

  Poor root growth and discoloured leaves
• What is potassium needed for in plants?

  For enzyme reactions to produce ATP and for photosynthesis
• What are the effects of a lack of potassium in plants?

  Poor growth of flowers and fruits, and brown spots on leaves
• Why is pest control important in agriculture?

  Pests can damage crops and reduce yields

  
• What are the two main types of pest control?

  Pesticides and biological control

  
• What do insecticides target?

  Insect pests

  
• What do herbicides target?

  Plant pests
• What do fungicides target?

  Fungal pests

  
• How does biological control work?

  A species is introduced to prey on the pest species

  
• What is the role of yeast in bread production?


  Yeast ferments sugars to produce carbon dioxide and alcohol

  
• What happens to yeast during bread making?

  Yeast produces enzymes that break down starch into sugars

  
• What type of respiration does yeast switch to when oxygen runs out?

  Anaerobic respiration

  
• What gas is produced by yeast during anaerobic respiration?

  Carbon dioxide

  
• What happens to the dough during baking?

  The carbon dioxide causes the dough to rise

  
• What happens to the ethanol produced by yeast during baking?


  It evaporates in the heat

  
• What is the purpose of the oil layer in the yeast experiment?

  To prevent oxygen from entering the solution

  
• What is measured in the yeast experiment to assess anaerobic respiration?

  The number of bubbles produced

  
• What is the effect of temperature on yeast respiration?

  Higher temperatures increase the rate until enzymes denature

  
• What is the role of Lactobacillus in yoghurt production?

  It produces enzymes that turn milk into yoghurt
• Why are microorganisms useful in food production?

  They can produce complex molecules and reproduce rapidly
• What is the purpose of an industrial fermenter?

  To grow microorganisms in large amounts