Biology

Transport in Plants

Question:

Given below is a table. Fill in the gaps.

  Property

Simple

diffusion

Facilitated

transport

Active

transport

i. Highly selective   Yes  
ii. Uphill transport     Yes
iii. Requires ATP      
     

 

Answer:

 

  Property

Simple

diffusion

Facilitated

transport

Active

transport

i. Highly selective No Yes Yes
ii. Uphill transport No No , Yes
iii. Requires ATP No No Yes
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Transport in Plants

Q 1.

Given below is a table. Fill in the gaps.

  Property

Simple

diffusion

Facilitated

transport

Active

transport

i. Highly selective   Yes  
ii. Uphill transport     Yes
iii. Requires ATP      
     

 

Q 2.

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 _________

Q 3.

Movement of substances in xylem is unidirectional while in phloem it is bidirectional. Explain.

Q 4.

Match the following and choose the correct option.

A. Leaves (i) Anti-transpirant
B. Seed (ii) Transpiration
C. Roots (iii) Negative osmotic potential
D. Aspirin (iv) Imbibition ‘
E. Plasmolyzed cell (v) Absorption

Options:
(a) A—(ii), B—(iv), C—(v), D—(i), E—(iii)
(b) A—(iii), B—(ii), C—(iv), D—(i), E—(v)
(c) A—(i), B—(ii), C—(iii), D—(iv), E—(v)
(d) A—(v), B—(iv), C—(iii), D—(ii), E—(i)

Q 5.

Briefly describe water potential. What are the factors affecting it?

Q 6.

Describe transpiration pull model of water transport in plants. What are the factors influencing transpiration? How is it useful to plants?

Q 7.

Discuss the factors responsible for ascent of xylem sap in plants.

Q 8.

Describe the role played by protein pumps during active transport in plants.

Q 9.

A flowering plant is planted in an earthen pot and irrigated. Urea is added to make the plant grow faster, but after some time the plant dies. This may be due to ________.

Q 10.

What happens when a pressure greater than the atmospheric pressure is applied to pure water or a solution?

Q 11.

What essential role does the root endodermis play during mineral absorption in plants?

Q 12.

Identify the process occurring in I, II and III.

 

Q 13.

Explain why pure water has the maximum  water potential.

Q 14.

How is the mycorrhizal association helpful in absorption of water and minerals in plants?

Q 15.

Osmosis is a special kind of’diffusion, in which water diffuses across the cell membrane. The rate and direction of osmosis depends upon both ________

Q 16.

What are porins? What role do they play in diffusion?

Q 17.

Smaller, lipid soluble molecules diffuse faster through cell membrane, but the movement of hydrophilic substances are facilitated by certain transporters which are chemically ________.

Q 18.

What causes the opening and closing of guard  cells of stomata during transpiration?

Q 19.

Describe transpiration pull model of water transport in plants. What are the factors influencing transpiration? How is it useful to plants?

Q 20.

In a passive transport across a membrane, when two protein molecules move in opposite direction and independent of each other, it is called as ________

Q 21.

The plant cell cytoplasm is surrounded by both cell wall and cell membrane. The specificity of transport of substances are mostly across the cell membrane, because _________ .

Q 22.

Absorption of water from soil by dry seeds increases the ________ thus helping seedlings to come out of soil.

Q 23.

The C4 plants are twice as efficient as C3 plants in terms of fixing C02 but lose only _________ as much water as C3 plants for the same amount of C02 fixed.

Q 24.

Define water potential and solute potential.

Q 25.

Briefly describe water potential. What are the factors affecting it?

Q 26.

What are the factors affecting the rate of diffusion?

Q 27.

What role does root pressure play in water movement in plants?

Q 28.

Explain why xylem transport is unidirectional and phloem transport bidirectional.

Q 29.

What essential role does the root endodermis play during mineral absorption in plants?

Q 30.

Explain pressure flow hypothesis of translocation of sugars in plants.

Q 31.

(a) With fhe help of well-labelled diagrams, describe the process of plasmolysis in plants, giving appropriate examples.
(b) Explain what will happen to a plant cell if it is kept in a solution having higher water potential.

Q 32.

Differentiate between the following:
(a) Diffusion and Osmosis
(b) Transpiration and Evaporation
(c) Osmotic Pressure and Osmotic Potential
(d) Imbibition and Diffusion
(e) Apoplast and Symplast pathway of movement of water in plants
(f) Gutta’tion and Transpiration