Scientists examined how cuticle thickness affected water loss from the leaves of balsam fir, Abies balsamea. The leaves were sorted into three sets: A - thick cuticle, B - medium cuticle, C - thin cuticle. Samples from each set were weighed. The leaves were then left on a tray in dry air at 20 ^{\circ}C. At intervals over 15 hours, the samples were weighed again. The scientists worked out the mass of each sample as a percentage of its initial mass. Fig. 5.1 presents the findings.
(a(i))[5]
Describe and explain the trend shown in Fig. 5.1.
(a(ii))[3]
Suggest and explain the effect that this would have on the results.
(b)[2]
State one adaptation of the stem and one adaptation of the root in xerophytes.
(c(i))[1]
State the name of the other raw material required for photosynthesis.
(c(ii))[3]
State three ways a plant uses the sugars produced in photosynthesis.
Worked solution & mark scheme
This 14-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Leaf A (thick cuticle) showed the smallest loss of mass / water” …