A student investigates the rate of water uptake in a leafy shoot of common ivy, Hedera helix, using a potometer. The capillary tube of the potometer has an internal diameter of 1.0 mm1.0\text{ mm}1.0 mm. During a 40-minute period, the air bubble moves a distance of 32 mm32\text{ mm}32 mm along the capillary tube.
Calculate the rate of transpiration for this shoot in mm3 h−1\text{mm}^3\,\text{h}^{-1}mm3h−1. Give your final answer to 3 significant figures. Use the formula:
Volume of a cylinder=πr2l \text{Volume of a cylinder} = \pi r^2 l Volume of a cylinder=πr2lThe student also prepares a transverse section of the stem of H. helix and views it under a light microscope. In a micrograph of this section, a xylem vessel has an imaged width of 45 mm45\text{ mm}45 mm. The magnification of the micrograph is ×120\times 120×120.
Calculate the actual width of this xylem vessel in mm\text{mm}mm. Give your answer to 2 significant figures.
