(a)[3]
State the features of xylem vessels that let them transport water.
(b)[5]
Describe the route taken by water from outside the root to the xylem vessels (J) in the middle of the root. Use the letters in Fig. 3.1 in your answer.
(c(i))[2]
Calculate the percentage increase in average flow-rate from zone 1 to zone 3 for healthy roots. Give your answer to two significant figures. Show your working.
(c(ii))[3]
Describe how xylem vessel width in the different root zones affects the average flow-rate of water. Use the information in Table 3.1 in your answer.
(c(iii))[2]
Suggest why there was little difference between the flow-rate in healthy roots and that in roots treated with the toxic solution.