Tag: water absorption and ascent of sap in plants

Questions Related to water absorption and ascent of sap in plants

Water in plants is transported by or ascent of sap takes place through 

botany water absorption and ascent of sap in plants apoplast and symplastic pathway transport of water in plants water transport

  1. Cambium

  2. Phloem

  3. Xylem

  4. Epidermis

Show answer
Correct Option: C
Explanation:
Xylem contributes in ascent of sap by the following phenomena.
1) The rate of transpiration is high. 
2) The water is lost from guard cell which leads to decrease in the water potential of guard cell as compared to the surrounding cell. 
3) To stabilize the water potential in the guard cell water rushes from the neighbouring cell which creates a cohesion pull in the xylem vessels to pull the water up to the guard cell. 
So, the correct answer is option C.

Ascent of sap is

botany water absorption and ascent of sap in plants apoplast and symplastic pathway transport of water in plants water transport

  1. Upward movement of water in the plant.

  2. Downward movement of organic nutrients.

  3. Downward and upward movement of water in the plant.

  4. Redistribution of inorganic substances in the plant.

Show answer
Correct Option: A
Explanation:
  • Down to upwards movement is known as ascent and Top to downwards movement is known as descend.
  • In plants sap is water and minerals.
  • Ascent of sap in the xylem tissue of plants is the upward movement of water and minerals from the root to the top. 

The gridling or ringing experiment to prove that the water moves through the xylem vessels was performed by

botany water absorption and ascent of sap in plants apoplast and symplastic pathway transport of water in plants water transport

  1. Stocking

  2. Malpighi

  3. Molisch

  4. Askenasy

Show answer
Correct Option: B
Explanation:

This experiment was introduced by Malpighi in 1675. It involves the removal of a ring of bark (girdle), that is, all tissues outside the vascular cambium. Thus, the correct answer is (B).

The transport of sap from root to top of the plant is

botany water absorption and ascent of sap in plants apoplast and symplastic pathway transport of water in plants water transport

  1. Ascent of sap

  2. Conduction

  3. Transport

  4. Translocation

Show answer
Correct Option: A
Explanation:

When any material movement is from down to upwards it is called as ascending movement.

When material movement is from top to downwards it is called as descending movement.
The upward movement of water and minerals from the root to the top of the plant is called as ascent of sap. Plants absorb water through the root hairs and transpire through leaves. The water moves from the root to the tip portion of the plant body against the force of gravity by transpiration pull.

Sir J.C. Bose proposed a theory of ascent of sap known as 

botany water absorption and ascent of sap in plants apoplast and symplastic pathway transport of water in plants water transport

  1. Pulsation theory

  2. Transpiration pull theory

  3. Relay pump theory

  4. Capillary force theory

Show answer
Correct Option: A
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 A.

Transportation is helpful to plants in 

botany water absorption and ascent of sap in plants apoplast and symplastic pathway transport of water in plants water transport

  1. Cooling

  2. Loss of excess nutrients

  3. Upward conduction/ascent of sap

  4. Loss of excess water

Show answer
Correct Option: C
Explanation:

Transportation is the process involving the transfer of materials from one place to another place.

(A)In plants, cooling occurs through transpiration.
(B)Plants loss excess nutrients and water through their aerial parts.
(C)Transportation helps in the ascent of sap or food.
(D)Transpiration is the loss of excess water.
So, the correct answer is 'Upward conduction/ ascent of sap'.

According to the vital force theory, ascent of sap is due to active pulsation of the innermost layer of cortex. This theory was given by 

botany water absorption and ascent of sap in plants apoplast and symplastic pathway transport of water in plants water transport

  1. J. C. Bose

  2. Dixon

  3. Strasburger

  4. Sachs

Show answer
Correct Option: A
Explanation:

According to the vital force theory, ascent of sap is due to active pulsation of the innermost layer of cortex. This theory was given by J.C Bose. 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 when the cells were dead.

So, the correct answer is option A.

In plants, water moves from 

botany water absorption and ascent of sap in plants apoplast and symplastic pathway transport of water in plants water transport

  1. Less negative to more negative gradient

  2. More negative to less negative gradient

  3. Similar gradient

  4. Zero gradient

Show answer
Correct Option: B
Explanation:
In plants, water is absorbed by roots from the soil and it has to get transported to all parts of the plant. Water moves only from the more negative gradient to a less negative or positive gradient. As when water concentration is high then the gradient is more negative and water always move from the higher concentration to lower concentration.
So, the correct answer is 'More negative to less negative gradient'.

The rupture or fractionation do not usually occur in the water coloumn in vessels / tracheids during the ascent of sap because of

botany water absorption and ascent of sap in plants apoplast and symplastic pathway transport of water in plants water transport

  1. lignified thick walls

  2. cohesion and adhesion

  3. weak gravitational pull

  4. transpiration pull

Show answer
Correct Option: B
Explanation:

The rupture or fractionation do not usually occur in the water column in vessels/ tracheids during the ascent of sap because of cohesion and adhesion. This is because continuity of water column is maintained by cohesion and adhesion. The conduction of water from root to aerial parts of plants is called ascent of sap. The water molecules remain attached to each other by cohesion force. The magnitude of this force is very high. This helps in the continuous water column in the xylem. The adhesive force is present between the water molecules and the walls of xylem. This also helps in continuous water column in the xylem.

Thus, the correct answer is option B.

A column of water within xylem vessels of tall trees does not break under its weight because of

botany water absorption and ascent of sap in plants apoplast and symplastic pathway transport of water in plants water transport

  1. Dissolved sugar in water

  2. Tensile strength of water

  3. Lignification of xylem vessels

  4. Positive root pressure

Show answer
Correct Option: B
Explanation:

The tensile strength of water is its ability to resist the effect of external stress and maintain it's flow. The transpiration all pull exerts great stress on the water column but due to its tensile strength, it doesn't break in between.

Dissolved sugar increases the solute potential while root pressure provides a push to water only up to a certain extent.
Lignin provides mechanical support to the xylem vessels.
So the correct answer is 'Tensile strength of water'.