Cambridge International A Level Biology Revision Guide

Chapter 7: Transport in plants
End-of-chapter questions
1 If sucrose is actively loaded into a sieve tube, which combination of changes takes place in the sieve tube?
Solute potential
Hydrogen ion concentration
A decreases (becomes more negative) decreases
B decreases (becomes more negative) increases
C increases (becomes less negative) decreases
D increases (becomes less negative) increases
2 Which of the following rows correctly describes the hydrostatic pressure of the two types of elements?
Hydrostatic pressure
Xylem vessel element
Phloem sieve element
A negative negative
B negative positive
C positive negative
D positive positive
3 The diagram shows the effect of light intensity on the rate of transpiration from the upper and lower epidermis of
a leaf. Other environmental factors were kept constant. What could explain the differences in transpiration rates
from the two surfaces?
[1]
[1]
lower epidermis
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Rate of transpiration
upper epidermis
Light intensity
A Higher light intensities are associated with higher temperatures.
B The palisade mesophyll cells have fewer air spaces than the spongy mesophyll cells.
C The upper epidermis has fewer stomata.
D The upper epidermis is more exposed to light. [1]
4 Explain how water moves from:
a the soil into a root hair cell [3]
b one root cortex cell to another [4]
c a xylem vessel into a leaf mesophyll cell. [3]
[Total: 10]