1. 1
   A commercial tomato grower cultivates plants in a large glasshouse. To increase crop yield, the grower pumps additional carbon dioxide gas into the glasshouse air and keeps the temperature at a steady 24°C throughout the day.

   (a)

   Which raw material is being artificially increased inside the glasshouse to raise the rate of photosynthesis?

   [1 mark]

   • AOxygen
   • BCarbon dioxide
   • CNitrogen
   • DWater vapour

   (b)

   Which of the following is a product of photosynthesis that provides the plant with a store of chemical energy?

   [1 mark]

   • AGlucose
   • BOxygen
   • CCarbon dioxide
   • DWater

   (c)

   Explain why, once the light intensity in the glasshouse becomes very high, further increases in carbon dioxide concentration alone will not increase the rate of photosynthesis any further.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A doctor is advising a woman who has recently found out she is pregnant about how her diet should change over the coming months to meet the needs of her developing baby.

   (a)

   Which mineral ion is especially important during pregnancy for the formation of the baby's bones and teeth?

   [1 mark]

   • AIron
   • BCalcium
   • CSodium
   • DMagnesium

   (b)

   Which nutrient is most needed in increased amounts to support the growth of new cells and tissues in the developing baby?

   [1 mark]

   • ADietary fibre
   • BProtein
   • CVitamin C
   • DWater

   (c)

   Explain why a pregnant woman needs to increase her iron intake during pregnancy.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A student eats a lunch of bread, chicken and chips. As the meal moves through his alimentary canal it is mechanically and chemically broken down before the nutrients can be absorbed into his blood.

   (a)

   Describe how the meal is moved along the alimentary canal and broken down in the stomach.

   [3 marks]

   (b)

   Explain the roles of bile and lipase in the digestion of the fat in the chips as the food reaches the small intestine.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A charity is investigating cases of malnutrition in a rural community where many children show signs of poor growth despite eating enough food, suggesting a problem with digestion or absorption of nutrients rather than food availability.

   (a)

   Explain how the structure of the small intestine is adapted to allow efficient absorption of digested food into the blood.

   [6 marks]

   (b)

   Explain, using your knowledge of digestive enzymes, why a child could show signs of malnutrition even if he or she eats a normal, varied diet.

   [6 marks]

   Total for question 4: 12 marks

End of questions