Tar in tobacco smoke has several effects on the cells lining the gas exchange system. State the main effects of tar on the cells lining the gas exchange system that are linked to lung cancer and to chronic bronchitis. lung cancer ........................................................... chronic bronchitis ...........................................................
A student studied how SA:V affects diffusion. Agar was made using Universal Indicator solution and sodium hydroxide solution. The agar was coloured blue. Three cubes, A, B, and C, were cut from a solid block of blue agar. Each cube had a different size. Universal Indicator solution turns red in the presence of acid. The student prepared Table 4.1 to show the sizes and SA:V of each cube. Complete Table 4.1 by: - giving the correct units for volume - working out the total surface area, and volume, of cube C.
Cubes A, B and C were put into a small beaker. At time 0 seconds, dilute hydrochloric acid was poured into the beaker to cover the cubes. The student measured how long it took for each cube to change colour completely. Complete Fig. 4.1 to show the results that were obtained. cube ................. $\rightarrow$ cube ................. $\rightarrow$ cube .................
Some people who have emphysema may be given lung volume reduction surgery (LVRS), in which diseased lung tissue is surgically removed. One likely outcome of the operation is an improvement in total lung surface area to volume ratio (total lung SA:V). Suggest why total lung SA:V improves after the surgery has been carried out.
In humans, blood that becomes oxygenated in the lungs reaches body tissues without meeting blood that is deoxygenated. Explain how the blood that becomes oxygenated in the lungs is kept separate from blood that is deoxygenated.