A scientist investigated the effect of temperature on the rate of transpiration from leaves. Fig. 6.2 shows the apparatus used. The mass of the leafy shoot and test-tube of water was measured at 0 minutes and at 60 minutes. The apparatus was used at a range of temperatures. All variables apart from temperature were kept the same. There was no air movement during this investigation. Fig. 6.2 Table 6.1 shows the results. Table 6.1 (i) Calculate the mass lost at $$$20^{\circ} \mathrm{C}$$$. Write your answer in Table 6.1. (ii) Calculate the percentage decrease in mass at $$$25^{\circ} \mathrm{C}$$$. Give your answer to the nearest whole number. Space for working. ......................................................... $$$\%$$$

Biology

IGCSE&ALevel

CAIE

Exam No：0610_s24_qp_33 Year：2024 Question No：6(c)

Answer:

Knowledge points:

8.3.1 State that water is transported from the roots to leaves through the xylem vessels

8.3.2 Define transpiration as loss of water vapour from plant leaves by evaporation of water at the surfaces of the mesophyll cells followed by diffusion of water vapour through the stomata

8.3.3 Investigate and describe the effects of variation of temperature and humidity on transpiration rate

8.3.4 Explain how water vapour loss is related to the large surface area of cell surfaces, interconnecting air spaces and stomata

8.3.5 Explain the mechanism by which water moves upwards in the xylem in terms of a transpiration pull that draws up a column of water molecules, held together by cohesion

8.3.6 Explain how and why wilting occurs

8.3.7 Explain the effects of variation of temperature and humidity on transpiration rate

Answer:

Knowledge points:

Solution:

Related Question