Question 13
[Maximum number: 1]
On a dry, sunny day, how does water vapour move through the stomata of a leaf?
A
into the leaf by diffusion
B
into the leaf by respiration
C
out of the leaf by diffusion
D
out of the leaf by respiration
IGCSE Biology Extended 8.3.2—Water evaporates from the surfaces Topic Practice
8.3.2—Water evaporates from the surfaces
• State that water evaporates from the surfaces of the mesophyll cells into the air spaces and then diffuses out of the leaves through the stomata as water vapour
Question 16
[Maximum number: 1]
The diagram shows a cross-section through a leaf.
From which cell will most water evaporate during transpiration?
Question 3(a)(iii)
[Maximum number: 1]
Fig. 3.1 shows some apparatus that was used to investigate water loss from a leafy shoot.
Fig. 3.1
State the purpose of the oil layer on top of the water in the burette.
Question 17
[Maximum number: 1]
The diagram shows one of the stomata of a leaf, and some of the cells that are near it.
During transpiration, what describes the movement of water at X and at Y ?
movement of
water at X
movement of
water at Y
evaporation
diffusion
evaporation
osmosis
osmosis
diffusion
osmosis
osmosis
Question 6(a)(ii)
[Maximum number: 3]
Some students set up the apparatus shown in Fig. 6.1 to compare transpiration in two sets of leaves.
Set A was kept in a transparent bag and set B was left in the open air.
All other conditions were kept constant.
The mass of the leaves in each set was measured at the start of the investigation and after five hours.
Fig. 6.1
Explain how transpiration occurred in the leaves shown in Fig. 6.1.