Tag: water absorption and ascent of sap in plants

Questions Related to water absorption and ascent of sap in plants

Terms apoplast and symplast were first used by

  1. Clark

  2. Munch

  3. Dixon

  4. Lundegardh


Correct Option: B
Explanation:

Apoplast refers to the non living component of plant like intercellular spaces and cell wall. Transportation through apoplast is fast. 

Symplast refers to living component of plant ie cell membrane and protoplasm. Transportation through symplast is slow process. 
E. Munch (1932), a German physiologist introduced the concept of apoplast and symplast, which is valuable in understanding the pathway of water movement through the root.

Choose the correct answers from the alternatives given.
If cell A with OP = 5 and TP = 4 is surrounded by cells with OP = 3 and TP = 1, what will be the direction of water movement?

  1. From other cells to cell A

  2. From cell A to other cells

  3. Water will not move

  4. None of these


Correct Option: B
Explanation:

DPD or diffusion pressure deficit determines the flow of water. Water moves from low DPD to high DPD. 

DPD is given by: DPD = OP - TP.
In cell A, DPD = 5 - 4 = 1.
In other cells, DPD = 3 - 1 = 2.
Since water moves from low DPD to high DPD, here the movement occurs from cell A to the other cells.
Hence, the correct answer is 'From cell A to other cells'.

The transportation of water and minerals from the root to the leaves is known as ________

  1. Capillary action

  2. Accent of sap

  3. Climbing

  4. Transportation


Correct Option: B
Explanation:

The transportation of water and dissolved minerals from the root to the leaves is known as ascent of sap. It is transported through xylem tissues. During transportation, there is large accumulation of mineral ions in the root hair cells by active transport. This results in the higher water concentration in the soil as compared to the cell sap of the root hair. Hence, water diffuses from the soil into the root hair. The root hair cells become turgid. From root hair cells, the water moves into the cortical cells. From the cortical cells, the water reaches the endodermis by osmosis. The endodermis then pushes water into the xylem tubes through passage cells.

Thus, the correct answer is 'Ascent of sap.'

Which is shown by the experiment Ascent of sap?

  1. The food materials are transmitted by phloem

  2. Water is transmitted by phloem

  3. Water is transmitted by xylem

  4. The food material is transmitted by xylem


Correct Option: C
Explanation:

The ascent of sap experiment demonstrates the absorption of water by root cells if plants and their upwards movement. The sap is the water and minerals absorbed by the roots and they are pushed upwards into the xylem and then it goes to other regions of the plant.

The upward movement of water and minerals is known as ascent of sap.
So the correct answer is 'Water is transmitted by the xylem'.

Ascent of sap will be maximum during

  1. Daytime

  2. Night time

  3. Early morning

  4. None of the above


Correct Option: A
Explanation:

Cohesion transpiration pull theory was put forward by Dixon and Jolly in 1894. It is also known as Dixon's theory of ascent of sap. During day time, there will be maximum water loss due to transpiration, hence, transpiration pull will also be maximum during day time. Consequently, maximum ascent of sap will occur during day time.

The rate of transpiration ........... the process of ascent of sap.

  1. Increases

  2. Decreases

  3. Do not affect

  4. Increases and then decreases


Correct Option: A
Explanation:

Transpiration causes the development of a pull or a negative pressure region which created a suction force to aid the ascent of sap. It increases the process of ascent of sap.

So the correct answer is 'Increases'.

The root pressure theory considers ........... responsible for the ascent of sap.

  1. Gravitational pull

  2. Hydrostatic pressure

  3. Capillary force

  4. None of the above


Correct Option: B
Explanation:

The root pressure theory considers that hydrostatic pressure developed in the roots is responsible for pushing the water through the column. It depends on the active accumulation of minerals in the root cells which then causes passive absorption of water creating a high pressure.

It neglects the effect of gravity.
Capillary force is not the driving force in this theory.
Many small herbaceous plants only depend on root pressure for ascent of Sap.
So the correct answer is ' Hydrostatic pressure'.

Organic and mineral nutrients undergo______

  1. Unidirectional

  2. Bidirectional

  3. Multidirectianal

  4. Both A and B


Correct Option: D
Explanation:

Organic material in plants is transferred by phloem while water and mineral nutrients are transferred by xylem. It is a well-known fact that xylem only has unidirectional transport of water while phloem can exhibit bidirectional transport.

So, the correct answer is 'Both A and B'.

Movement of water and mineral salts in plant is __________.

  1. Osmosis

  2. Absorption

  3. Ascent of sap

  4. Active absorption


Correct Option: C
Explanation:

Ascent of Sap : Ascent of sap in the xylem tissue of plants is the upward movement of water from the root to the crown.

Pulsation theory was proposed by

  1. Godlewski

  2. Jagadish Chandra Bose

  3. Dixon and Joly

  4. Arthur


Correct Option: B
Explanation:
Sir J.C. Bose proposed a theory of ascent of sap known as pulsation theory. The pulsation theory states that water is absorbed by the plants due to the metabolic activity of living cells which are in constant state of rythmatic pulsation. But it was not accepted as water can be passively absorbed by the roots even the cells were dead.
So, the correct answer is option B.