3.3 Exchange of Substances

Practice questions on Exchange of Substances

• Explain how blood is transported from the heart to the lungs and back to the heart, and wh… (5 marks, Explain)
• Explain why a large multicellular organism cannot rely on diffusion alone to supply all of… (5 marks, Explain)
• Describe the roles of bile and pancreatic juice in the digestion of food in the small inte… (5 marks, Describe)
• Explain why insects, which are small invertebrates, can supply oxygen to their body cells … (5 marks, Explain)
• Explain how the structure of a red blood cell is adapted to carry oxygen efficiently aroun… (5 marks, Explain)
• Explain how the structure of a capillary is adapted for the exchange of substances between… (5 marks, Explain)
• Describe how the structure of the human circulatory system is adapted to supply all body c… (5 marks, Describe)
• Explain how enzymes in the digestive system break down a protein-rich meal into molecules … (5 marks, Explain)
• Explain what happens to a fat molecule during digestion, including where digestion occurs … (5 marks, Explain)
• Explain why large multicellular organisms need a mass transport system, but single-celled … (5 marks, Explain)
• Explain why the digestion of starch is necessary before it can be absorbed into the blood. (5 marks, Explain)
• Explain how the small intestine is adapted to absorb the products of digestion efficiently… (5 marks, Explain)
• Explain how the structure of a leaf is adapted for efficient gas exchange. (5 marks, Explain)
• Explain how gas exchange occurs in an insect, referring to the structures involved and the… (5 marks, Explain)
• Explain how gas exchange occurs in fish gills and why the counter-current system makes thi… (5 marks, Explain)
• A student investigates gas exchange in a plant. They place a leafy shoot in bright light a… (5 marks, Describe)
• Explain why a fish uses specialised gill structures to obtain oxygen from water, rather th… (5 marks, Explain)
• Explain why a multicellular animal such as a mouse needs both a specialised gas exchange s… (5 marks, Explain)
• Explain why, as an organism increases in size, it requires specialised exchange surfaces a… (5 marks, Explain)
• Explain why a leaf is adapted to exchange gases efficiently with the surrounding air. (5 marks, Explain)