OBJECTIVES
1.
Mineral salts can be
absorbed into the roots by
A. osmosis only
B. osmosis and diffusion
C. diffusion and active transport
D. imbibition only
2. A physiological adaptation of plants
to the problem of excessive water loss is
A.
reduction in the number of stomata
B.
reversal of the normal stomatal rhythm
C.
possession of shallow roots
D. possession
of waxy cuticle
3. If a
ring of bark and phloem is removed from a stem, the
A.
plant dies immediately
B.
plant dies after two days
C.
movement of food is not affected
D.
movement of minerals is hardly affected
4.
Transpiration can be measured
with a
A. photometer
B. hygrometer
C. potometer
D. barometer
5.
Which of the
following can bring about the greatest increase in the rate of transpiration?
A. Increased humidity
B. Reduced temperature
C. Reduced wind speed
D. Reduced humidity
6.
Manufactured food
in the plant is transported through the
A. xylem
B. phloem
C. cambium
D. cortex
7.
Oozing out of water from
the leaves of plants in a humid environment is known as
A. transpiration
B. osmosis
C. pinocytosis
D. guttation
8.
In the whistling pine,
leaves are reduced to brown scales and young stems are green. This is an
adaptation for
A. obtaining food
B. conserving
nutrients
C. storing water
D. reducing transpiration
9.
Substance manufactured by
the leaves are transported to other parts of the plant through the
A. xylem
B. companion cells
C. sieve tubes
D. cambium
10. The force that holds water together in the form of a stream within
the xylem tube is the
A. cohesion of water
molecules to one another by hydrogen bonds
B. force of gravity
attacking the water molecules through the hydrogen bonds
C. attraction
between the water and xylem osmotic force
D. normal flow of water from
the ground with help of gravitational force
11. Salts and water are absorbed in the roots and transported to leaves
by
A. diffusion through
the xylem tissues
B. osmosis through
the phloem tissues
C. diffusion through
the phloem tissues
D. osmosis through the
xylem tissues
12. If water that has been coloured red is poured at the base of a
wilting plant, it will appear as a red stain in the cells of the
A. xylem
B. epidermis
C. phloem
D. parenchyma
13. The presence of sunken stomata and the folding of leaves are
adaptations to
A. Prevent entry of
pathogens
B. Reduce water loss
C. Remove excess
water
D. Prevent guttation
14. Excess water in plants is excreted as water vapour and droplets
respectively through
A. respiration and
guttation
B. transpiration and
guttation
C. photosynthesis
and guttation
D. guttation and
condensation
15. The loss of water vapour through the aerial parts of the plant to
the atmosphere is called
A. respiration
B. guttation
C. osmoregulation
D. transpiration
16. The upward movement of the sap in the xylem vessel is brought about
by
A. transpiration
stream
B. guttation
C. capillarity
D. osmosis
17. Water vapor is lost in plants during transpiration through
A. stomata and lenticels
B. xylem and stomata
C. sclerenchyma and
stomata
D. parenchyma and
lenticels
18. Transpiration enhances
A. continuous stream
of water through the plant
B. absorption of
water by the plant cell
C. continuous
closure of the stomata
D. translocation of plant
food
19. Which of the following pathway is taken from soil to xylem?
A. root hair→
piliferous layer → xylem
B. root hair →
cortex →piliferousblayer → xylem
C. root hair →
piliferous layer → cortex → xylem
D. root hair → cortex →
xylem
20. Which of the following statement about transpiration is true?
A. the plant is
cooled during transpiration
B. transpiration
occurs most in upper surface of a leaf
C. transpiration
occur only in leaves
D. transpiration occurs
more in the night than in the day
Answers
|
1. C
|
6. B
|
11. D
|
16. C
|
|
2. B
|
7. D
|
12. A
|
17. A
|
|
3. D
|
8. D
|
13. B
|
18. A
|
|
4. C
|
9. B
|
14. B
|
19. C
|
|
5. D
|
10. A
|
15. D
|
20. A
|
THEORY
1.
(SSCE 1998) (a) Explain how plant obtains
(i) Water
(ii)
mineral salts
(b) Describe the pathway and mechanisms of water transport in the plant.
Solution
(a) (i) Water is mainly absorbed
by root hairs of plants. They are numerous and greatly increase the surface
area of the root available for absorption. They lack cuticle and have thin cell
walls. All these characteristics are adaptations of roots for absorption of
water from the soil by osmosis.
(ii) Mineral salts are found in
ionic form, dissolved in the soil water surrounding the roots. Depending on the
mineral salt required by the plant, the roots hairs absorb the salts by
diffusion along concentration gradient or against concentration gradient by
active transport.
(b) Water enters the root hairs by
osmosis. Water from the soil, dilutes the cell sap of the root hair and moves
across the cortex along an osmotic gradient, into the xylem. Continuous
absorption of water by root hairs generates a pressure called root pressure,
moves water along the xylem. As a result of cohesion, adhesion and capillarity
through xylem vessel, water moves from the xylem through the cells of the
lamina by osmosis, which results from transpiration through the stomata. The
transpiration also set up tension in the xylem vessels. This tension pulls the
rest of the water column upwards, a process known as transpiration pull.
2. (SSCE 2004 Q5) (a) (i) How can it be proved
experimentally that plants lose water during transpiration?
(ii) Name four environmental factors that affect the rate of rate
transpiration in plants.
(b) What is the importance of transpiration to plants?
(c) List four features of plant that enable them to control
excessive loss of water through plants transpiration.
Solution
(a)
(i) Refer to blog content
(ii) Temperature, light, wind,
relative humidity
(b) Refer to blog content
(c) Modifications controlling excessive loss of water
·
Curled up leaves
●
Sunken stomata
·
Presence of hairs and scales
·
Presence of thick cuticle
·
Reduction of leaf size
3. (SSCE 2005 Q1) (a) (i) Distinguish between
transpiration and guttation.
(ii) Under what condition does guttation occur?
(b) (i) Describe the mechanism of transpiration
(ii) What is the importance of transpiration?
Solution
Transpiration is the loss of water in the form of water vapor from the aerial parts of
the plant mainly through the leaves while
Guttation is the exuding of drops of water on the tips or edges of leaves.
(ii) Refer to blog content
(b) Mechanism of
transpiration
Water molecules evaporate from the
surface of spongy mesophyll cells into the intercellular spaces. Where the
water diffuses out through the stomata into the atmosphere. The sap of the
mesophyll cell become more concentrated and water is drawn into them from
neighboring cells by osmosis. This continues until the water is eventually
drawn from the xylem vessels in the veins.
(ii) Refer to blog content
4. (WASSCE 2014) Name the biological phenomenon
used to describe loss water from plants when transpiration is impossible.
(ii) State two condition under which the phenomenon named in (f)(i) above
occurs
Solution
(f)(i) Guttation
(ii) Refer to blog content
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