(a)[2]
Define what is meant by transpiration.
(b)[1]
Use Table 5.1 to work out the mean rate of movement of the bubble.
(c)[2]
The student repeated the investigation using the same plant. In this experiment a fan was used to blow air across the leaves of the plant. All other variables were standardised. The results showed that the bubble moved further in $10$ minutes. The student concluded that air movement increases the rate of transpiration. Explain why air movement increases the rate of transpiration.
(d)[4]
Explain how water moves up through a xylem vessel in the stem of the plant in the potometer, shown in Fig. 5.1.