2019

• Suggest one other reason for the reduced number of deaths from malaria each year

  Improved healthcare
• How does diabetes cause body cells to lose more water

  The blood is more concentrated so water moves out of the cell by osmosis through a partially permeable membrane
• How is the small intestine adapted for efficient absorption

  • long projections called villi which give it a large surface area: volume maximising absorption efficiency
  • Walls are one cell thick for short diffusion distance
  • Small intestine is very long increasing time for absorption
  • Rich blood supply maintains steep concentration gradient for diffusion
  • Many mitochondria for energy released from respiration for active transport
• What type of cell divides when a new gill grows

  stem cells
• One condition that could be treated using regenerated human tissue

  • paralysis
  • Diabetes
• Explain how pancreatic cancer can cause a person to lose weight. Do not refer to hormones in your answer

  • reduced enzyme production
  • Food is not fully broken down or digested
  • So less glucose is absorbed in the blood
  • So less respiration so more fat is used up in metabolism
  • Fewer fatty acids absorbed so less fat stored in the body
  • Fewer amino acids absorbed into bloodstream so less protein for repair
  • Chemo causes nausea so less intake of food