Tag: ascent of sap

Questions Related to ascent of sap

Force for active water absorption is present in

botany water absorption and ascent of sap in plants factors affecting the transport of water and minerals in plants ascent of sap long distance transport of water

  1. Xylem

  2. Aerial parts

  3. Root

  4. Root hairs

Show answer
Correct Option: C
Explanation:

Active water absorption is the absorption of water due to forces present in the root. Living cells in active metabolic condition are essential for this. Auxins are known to enhance water absorption (even from hypertonic solution) while respiratory inhibitors reduce the same.

Thus, the correct answer is option (C). 

Cohesive force of water molecules is of the magnitude of 

botany water absorption and ascent of sap in plants factors affecting the transport of water and minerals in plants ascent of sap long distance transport of water

  1. 1 - 10 atm

  2. 10 - 15 atm

  3. 45 - 200 atm

  4. 15 - 45 atm

Show answer
Correct Option: C
Explanation:
Cohesive force is called as the tensile strength of water. It is the force which acts between the water molecules. The cohesive strength of 47-207 atm. in xylem sap is sufficient to meet the stress of transpiration pull so that water column does not break.
Thus, the correct answer is option (C). 

Rate of water absorption is slow near freezing point because 

botany water absorption and ascent of sap in plants factors affecting the transport of water and minerals in plants ascent of sap long distance transport of water

  1. Water absorption is a metabolic process

  2. Cell growth stops

  3. Transpiration is reduced

  4. Cell membrane become more viscous

Show answer
Correct Option: D
Explanation:

Rate of water absorption is slow near a freezing temperature because decreased temperature results in the decreased root growth. Also, freezing temperature makes the cell membrane more viscous. There is resistance in water absorption as permeability of cell membrane decrease and viscosity increases.  

Thus, the correct answer is option D.

Prolonged water-logging kills plants due to

botany water absorption and ascent of sap in plants factors affecting the transport of water and minerals in plants ascent of sap long distance transport of water

  1. Stoppage of root respiration

  2. Dilution of soil nutrients

  3. Dilution of plant cell sap

  4. Leaching of nutrients

Show answer
Correct Option: A
Explanation:
Waterlogging is the saturation of soil with water which excludes air from the groundwater. If waterlogging will be prolonged then air cannot reach up to groundwater and root and it will result in the stoppage of root respiration.
So, the correct answer is 'Stoppage of root respiration'.

Which of the following is not an important factor in the regulation of transpiration?

botany water absorption and ascent of sap in plants factors affecting the transport of water and minerals in plants ascent of sap long distance transport of water

  1. Light

  2. Temperature

  3. Humidity

  4. Nitrogen content in the soil

Show answer
Correct Option: D
Explanation:

Transpiration is the evaporation of the water molecule from the upper surface of leaves.

(A) The intensity of light is directly proportional to the amount of transpiration.
(B) With the temperature increase, the transpiration also increases.
(C) Humidity also affects the rate of transpiration.
(D) The nitrogen content in the soil does not affect the regulation of transpiration.
So, the correct answer is 'Nitrogen content in the soil'.

The principle by which blotting paper absorbs water is 

botany water absorption and ascent of sap in plants factors affecting the transport of water and minerals in plants ascent of sap long distance transport of water

  1. Capillary action

  2. Transpiration pull

  3. Root pressure

  4. Absorptive capacity

Show answer
Correct Option: A
Explanation:
(A)Capillary action is the name of force by which water or any sap is pulled upwards direct through fine fibres or tubes. Blotting paper absorbs the water through capillary action only as thin threads like structure are present in blotting paper.
(B)Transpiration pull is also the process of upward movement of sap but it occurs during the process of transpiration.
(C)Root pressure is the transverse osmotic force causing sap rise in plants.
(D)Absorptive capacity is the capacity of absorption.
So, the correct answer is 'Capillary action'.

For ascent of sap, capillary force theory was first proposed by

botany water absorption and ascent of sap in plants factors affecting the transport of water and minerals in plants ascent of sap long distance transport of water

  1. Sachs

  2. Christian Wolf

  3. Strasburger

  4. Dixon and Joly

Show answer
Correct Option: B
Explanation:

Scientist Christian Wolf proposed the theory of capillary force for the ascent of sap. He proposed that when water is present in fine tubes then a force develops which causes ascent of sap which is known as capillary force.

So, the correct answer is 'Christian wolf'.

Capillarity theory is the most accepted theory of water movement through the plants.

botany water absorption and ascent of sap in plants factors affecting the transport of water and minerals in plants ascent of sap long distance transport of water

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

The cohesive-adhesive theory is the most accepted theory of water movement through the plants.

So, the correct answer is 'False'.

Passive absorption occurs due to 

botany water absorption and ascent of sap in plants factors affecting the transport of water and minerals in plants ascent of sap long distance transport of water

  1. Tension in root

  2. Tension in xylem sap

  3. ATP

  4. None of the above

Show answer
Correct Option: B
Explanation:

Passive absorption is the absorption without the use of energy or ATP.

It occurs when there is tension in xylem sap which causes concentration gradient and liquid moves without the use of energy according to the concentration gradient.
So, the correct answer is 'Tension in xylem sap'

Capillary pores are

botany water absorption and ascent of sap in plants factors affecting the transport of water and minerals in plants ascent of sap long distance transport of water

  1. Percolation pores

  2. Macropores

  3. Micropores

  4. Ultra micropores

Show answer
Correct Option: C
Explanation:

Water enters the soil through the pores by the means of capillary action and gravity. Capillary pores are micropores. Micropores hold maximum water by capillary forces. These pores have high water holding capacity as water within these pores is immobile. However, water is available for plant.

Thus, the correct answer is option C.