Transport in Plants AIIMS AIPMT PMT JIPMER NEET MCAT IBO Questions
- Which out of the four plant cells (R Q, Rand S) would not exhibit any wall pressure?
(a) P and Q (b) Q and S
(c) P and R (d) R and S
2. If cell A with DPD 5 atm is surrounded by many cells with DPD 4 atm then
(a) the net movement of water will be from cell A to the surrounding cells
(b) net movement of water will be from the : surrounding cells to cell A
(c) water will not move at all
(d) water movement will depend on other unknown factors.
3. If a cell A with DPD = 5 bars is connected to cells B,C and D, whose OP and TP are respectively 5 and 5,10 and 4, and 8 and 3, the flow of water will be
(a) C to A, B and D
(b) A and D to B and C
(c) A to B, C and D
(d) B to A, C and D.
4. The given diagram shows a potato plant forming new tubers. Which route would be taken by most of the food at this time?
(a) 1 —»4 —»2 —> 3 (b) 6 —> 5 —> 2 —>3
(c) 1 —> 4 —> 5 —> 6 (d) 6 —> 5—> 4 —> 1
5. Water moves up against gravity and even for a tree of 20 m height, the tip receives water within two hours. The most important physiological phenomenon which is responsible for the upward movement of water is
(a) Cohesive forces (b) adhesive forces (c) transpiration pull (d) root pressure
6. Stomatal opening and closing involves the role of various ions. In the given figure, arrows depict the movement of certain ions during stomatal opening in light. Identify the ions (P, Q, R and S) and select the correct option.
7. The cell A has an osmotic potential of-20 bars and a pressure potential of + 6 bars. What will be its water potential?
(a)-14 bars (b) +14 bars
(c) – 20 bars (d) – 26 bars
8. The diagram illustrates stomatal closing. The major mistake in the diagram is
(a) the concentration of the K+ should be more outside the guard cells
(b) the concentration of the K+ should be equal on both inside and outside
(c) the peripheral walls of the guard cells should be thicker
(d) the water should move inside the guard cells.
9. Which of the following has maximum water potential?
(a) Pure water
(b) 2% sucrose solution
(c) 4% glucose solution
(d) 10% sodium chloride solution
10. The osmotic potential and pressure potential of three cells (A, B, C) located in different parts of an actively transpiring plant are as following.
Which of the cells (A, B, C) have the highest water potential.
(a) A (b) B
(c) C (d) All of these.
11. Arrange the events of opening stomata in correct sequence and choose the correct option accordingly.
I. Lowering of osmotic potential of guard cells.
II. Decline in guard cell solute.
III. Rise of potassium ion level in guard cells.
IV. Guard cells absorb water from neighboring epidermal cells.
V. Guard cells become flaccid.
VI. Guard cells swell and make a pore between them.
(a) III, I, IV, V (b) I, II, III, IV, V, VI
(c) III, I, IV, VI (d) III, I, IV, VI, II, V
12. In the given schematic diagram, pathway of water movement inside the root is shown from soil to xylem. Identify the tissue involved in the steps A-C and choose the correct option accordingly.
(a) A – Hypodermis, B – Medullary rays, C – Metaxylem
(b) A – Cortex, B – Pericycle, C – Metaxylem
(c) A – Pericycle, B – Cortex, C – Metaxylem
(d) A – Hypodermis, B – Cortex, C – Vascular tissues.
13. Consider the following statements and choose the correct answer.
I. Carrier proteins are needed by both facilitated diffusion and active transport and are sensitive to inhibitors that react with protein side chain.
II. Different types of proteins present in the membrane play a major role in both active as well as passive transport.
III. The carrier proteins needed by facilitated and active transport are specific.
IV. There is no need of energy to pump molecule against a concentration gradient in active transport.
V. Transport rate reaches to saturation point, when all the active proteins are used.
(a) I, II, III, IV and V (b) I, II and III
(c) V, IV and I (d) I, II, III and V.
14. Why seeds kept in water swell up?
(a) OP inside the seed is low.
(b) OP of water is high.
(c) Water potential gradient develops between the seed coat and water.
(d) Diffusion pressure deficit of seed is very high.
15. Read the given statements regarding the different stages of plasmolysis and choose the correct option.
I. First stage of plasmolysis, when osmotic concentration of cell sap is just equivalent to that of external solution.
II. Protoplast withdraws itself from corners of the cell wall.
III. Protoplast gets detached from the cell wall and attains a spherical shape.
I II III
a Incipient plasmolysis Limiting plasmolysis Evident plasmolysis
b Limiting plasmolysis Incipient plasmolysis Evident plasmolysis
c Limiting plasmolysis Evident plasmolysis Incipient plasmolysis
d Evident plasmolysis Incipient plasmolysis Limiting plasmolysis
True or False type questions
16. The movement of water through apoplast is slow as it has to pass through the cell walls that provide a barrier to water movement.
17. As hydrostatic pressure in the phloem sieve tube decreases, pressure flow begins and the sap moves through the phloem.
18. Before leaf fall in deciduous plants, the minerals are remobilized to younger leaves.
19. The fungal filaments of a mycorrhiza form a network around the young root, and do not penetrate the root cells.
20. In a solution, the more the solute molecules, the greater (more positive) is the solute potential.
21. Special membrane proteins are needed only in active transport.
22. In a flowering plant, there is most probably a complex disorderly traffic of compounds moving in different directions, with each organ receiving some substances and giving out others.
23. In plant cells, the cytoplasm is the main determinant of movement of molecules in or out of the cell.
24. Due to the absence of any pumping organ in plants, the flow of water upwards, through the xylem in plants cannot achieve fairly high rates.
25. Transport proteins of endodermal cells are control points, where a plant adjusts the quantity and types of solutes that reach the xylem.
Match The Columns
26. Match Column-1 with Column-ll and select the correct option from codes given below.
A Mineral ions (i) Bidirectional
B Xylem (ii) Water vapour
C Guttation (iii) Protoplast
D Symplast (iv) Cell wall
E Apoplast (vi) Water droplets
F Transpiration (vii) Unidirectional
G Phloem (viii) Active absorption
27. Match Column-1 with Column-ll and select correct options from codes given below. There can be more than one match for items in Column I.
A. Root pressure (i) Positive
B. Diffusion (ii) Imbibition
C. Plasmolysis (iii) Wilting
D. Water potential (iv) Solute potential
E. Facilitated diffusion (v) Symport
F. Translocation (vi) Xylem
G. Symplast (vii) Plasmodesmata
(xi) Pressure potential
(xii) Hypertonic solution
Passage Based Questions
28.(A) Complete the given passage with appropriate words or phrases.
All solutions have a (i) water potential. If a pressure greater than atmospheric pressure is applied to pure water or solution, its water potential (ii).Pressure potential is usually (iii). though in plants (iv) potential in xylem plays a major role in water transport. Osmotic pressure is M pressure applied, while osmotic potential is (vi).
(B) Read the passage and correct the errors, wherever present.
C3 plants are twice as efficient as C4 plants in terms of fixing carbon. A C3 plant loses only half as such water as a C4 plant for the same amount of CO2 fixed.
Assertion & Reason
In each of the following questions, a statement of Assertion is given and a corresponding statement of Reason is given just below it. Of the statements, mark the correct answer as:
(a) if both A and R are true and R is the correct explanation of A
(b) if both A and R are true but R is not the correct explanation of A
(c) if A is true but R is false
(d) if both A and R are false.
29. Assertion : Mass or bulk flow is the movement of substance en masse from one point to another, as a result of pressure difference between the two points.
Reason: It can be achieved only through positive hydrostatic pressure.
30. Assertion : The opening of stoma is also aided due to the orientation of the microfibrils in the cell walls of the guard cells.
Reason : Cellulose microfibrils are oriented radially rather than longitudinally, making it easier for stoma to open.
31. Assertion : The process of loading at the source produces a hypotonic condition in the phloem.
Reason : That is the reason the phloem sap moves towards the sink.
32. Assertion : The chief sinks for the mineral elements are the older regions of the plant.
Reason: Elements most readily mobilised are calcium, phosphorus, nitrogen and potassium.
33. Assertion : Pressure potential is affected by both solute and water potential.
Reason : Pressure potential is always positive.
34. Assertion : In diffusion, molecules move in a random fashion.
Reason : Diffusion can be both uphill and downhill.
35. Assertion : Both facilitated diffusion and active transport are mediated through membrane proteins.
Reason : Only active transport is selective in action.
36. Assertion : Less than 1% of the water reaching the leaves is used in photosynthesis and plant growth.
Reason: Most of the water is lost through the stomata in leaves by transpiration.
37. Assertion : Water molecules are attracted to one another more than the water molecules in the gaseous state.
Reason : It produces surface tension that accounts for high capillarity through tracheids and vessels.
38. Assertion : Root pressure can provide a modest pull in the overall water transport in plants.
Reason : It does play an important role in water movement in tall trees.
Figure Based Questions
39. Refer to the figure given below. Identify the labelled A, B, C, D, E, F, G, 1 and 2
- Refer to the figure again and fill in the blanks using the given letters for the labelled parts and numerals 1, 2.
(a) (i) is the system of adjacent cell walls that is continuous throughout the plant, except at the (ii) of (iii) of the roots.
(b) The (iv) is the sytem of interconnected protoplasts through (v).
1. (c) 2. (b) 3. (d) 4. (b) 5. (c) 6. (c) 7. (a) 8. (a) 9. (a) 10. (c) 11. (c) 12. (b) 13. (d) 14. (c) 15. (b)
16. False. The apoplast does not provide any barrier to water movement, and it occurs through mass flow.
17. False. As the hydrostatic pressure in the phloem sieve tube increases, pressure flow begins, and the sap moves through the phloem.
19. False. The fungal filaments of a mycorrhiza form a network around the young root, and they penetrate the root cells.
20. False. The more the solute molecules in a solution, the lower (more negative) is the solute potential.
21. False. Special membrane proteins are needed for both active transport and facilitated diffusion.
22. False. It is a complex, most probably, orderly traffic of compounds moving in different directions.
23. False. In plant cells, the cell membrane and the membrane of the vacuole, or tonoplast are the main determinants of movement of molecules in or out of the cell.
24. False. The flow of water upwards through xylem in plants can be as high as 15 metres per hour.
26. A-(vii), B-(vi), C-(v), D-(iii), E-(iv), F-(ii), G-(i)
27. A-(i, xiv), B-(ii, xiii), C-(iii, xii), D-(iv, xi), E-(v, x), F-(vi, ix), G-(vii, viii)
28. (A) (i) lower, (ii) increases, (iii) positive, (iv) negative, (v)
positive, (vi) negative.
(B) ϵ4 C4 plants are twice as efficient as ϵ3 C3 plants in terms of fixing carbon. A ϵ3 C4 plant loses only half as much water as a ϵ4 C3 plant for the same amount of C02 fixed.
29. (c) 30. (a) 31. (d) 32. (d) 33. (d)
34. (c) 35. (c) 36. (a) 37. (a) 38. (d)
39. A – Epidermis; B – Cortex; C- Endodermis;
D – Pericyde; E – Casparian strip, F- Plasmodesmata, G – Xylem. 1 – Symplast; 2- Apoplast.
40. (a)-(i)2; (ii) E; (iii) C; (b) – (iv) 1; (v) F.