Name four factors that increase the rate of transpiration and explain why: What provides the following with a large surface area? Lungs: Small intestine: Leaves Roots Give three features common to efficient exchange surfaces. Define diffusion: Explain the appearance of the cell below when it is placed in a strong sugar solution. Why do cells of villi have the following features? Lots of mitochondria? Microvilli? Why is diffusion alone a sufficient means of transport in simple organisms but not large multicellular organisms? Image from Explain why most sports drinks contain: Water: Glucose: Ions: What process is used to exchange gasses in the lungs? Define active transport: Label the diagram of the lungs Complete the table to show the changes during ventilation InhalationExhalation Diaphragm Intercostal muscles Ribs Volume of thorax Pressure in lungs The iron lung helps a patient breathe through negative pressure. How does this work? How does carbon dioxide enter plants? How do the following substances get into plants? Water Mineral ions: Define transpiration: What cells control the opening and closing of stomata? Why do plants wilt in dry conditions? What processes are involved in the absorption of glucose after a meal and where do they take place?

Name four factors that increase the rate of transpiration and explain why: 1. Sunlight – causes stomata to open 2. High temperature – increases rate of evaporation 3. High winds – increases diffusion gradient 4. Low humidity / dry conditions – larger diffusion gradient What provides the following with a large surface area? Lungs: alveoli Small intestine: villi Leaves flat and thin; air spaces Roots root hair cells Give three features common to efficient exchange surfaces. 1. Large surface area 2. Thin to provide short exchange pathway 3. High concentration gradient (good blood supply / ventilation) Define diffusion: movement of a substance from an area of high concentration to low concentration Explain the appearance of the cell below when it is placed in a strong sugar solution. Water moves out the cell Across a partially permeable membrane From a dilute solution to a more concentrated one By osmosis Why do cells of villi have the following features? Lots of mitochondria? To release energy for active transport by respiration Microvilli? Increases surface area so speeds up exchange Why is diffusion alone a sufficient means of transport in simple organisms but not large multicellular organisms? Surface area to volume is too small in big organisms for substances to reach all cells quickly enough to meat metabolic demands Image from Explain why most sports drinks contain: Water: to replace lost fluids Glucose: to provide fuel for respiration Ions: to replace salts lost in sweat What process is used to exchange gasses in the lungs? Diffusion Define active transport: movement of a substance against a concentration gradient (from low concentration to high concentration) using energy in the form of ATP and carrier proteins Label the diagram of the lungs bronchus trachea alveoli diaphragm heart rib bronchiole Complete the table to show the changes during ventilation InhalationExhalation DiaphragmContracts and flattens Relaxs and domes Intercostal musclesContractRelax RibsUp and outDown and in Volume of thoraxIncreasesDecreases Pressure in lungsDecreasesIncreases The iron lung helps a patient breathe through negative pressure. How does this work? Iron lung creates a vacuum that causes the patient’s lungs to expand so air rushes in How does carbon dioxide enter plants? It diffuses into o leaves through the stomata. How do the following substances get into plants? Water Osmosis into the roots Mineral ions: diffusion or active transport into the roots Define transpiration: the loss of water from the leaves of a plant through the stomata What cells control the opening and closing of stomata? Guard cells Why do plants wilt in dry conditions? It reduces the surface area from which water can be lost What processes are involved in the absorption of glucose after a meal and where do they take place? Diffusion and active transport Villi of small intestine