Tag: absorption by roots - the processes involved

Questions Related to absorption by roots - the processes involved

Root pressure is maximum at the time of 

biology absorption by roots - the processes involved root pressure transportation in plants factors affecting the transport of water and minerals in plants

  1. Water absorption as well as transpiration.

  2. Both water absorption and transpiration are high.

  3. Absorption is low and transpiration is high.

  4. Absorption is high and transpiration is low.

Show answer
Correct Option: D
Explanation:
Root pressure is the negative pressure which helps in the ascent of water. The driving forces for water flow from roots to leaves i.e. root pressure is the lesser force and is important mainly in small plants at times when transpiration is not substantial and absorption is high.
So the correct answer is 'Absorption is high and transpiration is low'.

In the experiment to demonstrate root pressure, where did the cut was made on the plant? 

biology absorption by roots - the processes involved root pressure transportation in plants factors affecting the transport of water and minerals in plants

  1. At the tip

  2. Transition zone

  3. A few centimeters above the soil

  4. A few centimeters below the soil

Show answer
Correct Option: C
Explanation:
Root pressure is the transverse osmotic pressure within the cell of root that causes the rise of sap through the stem of the plant. So, to demonstrate root pressure the cut made is on the shoot just a few centimetres above from the ground.
So, the correct answer is 'A few centimetres above the soil'.

 Passive water absorption by root system is due to 

biology absorption by roots - the processes involved root pressure transportation in plants factors affecting the transport of water and minerals in plants

  1. Force created in roots

  2. Osmotic force In shoot

  3. High respiratory activity of root

  4. Tension in sap due to transpiration.

Show answer
Correct Option: D
Explanation:

Transpiration causes a negative pressure region in the xylem . The leaves and other apical parts require huge amounts of water as it is lost in Transpiration. So the stomata takes up the water from the intercellular spaces of the neighbouring cells that in turn draw water from the xylem . Hence a tension or negative pressure region is created in the xylem tissue. This process significantly drops the water potential in the xylem as well as the root region and the water potential of the soil is higher than the roots. So the roots start absorbing water passively as water flows from high water potential to low water potential. Hence Transpiration causes passive absorption of water in roots.

So the correct answer is 'Tension in sap due to transpiration'.

Root pressure is high when __________________.

biology absorption by roots - the processes involved root pressure transportation in plants factors affecting the transport of water and minerals in plants

  1. Transpiration is high and absorption of water is low.

  2. Transpiration is low and absorption of water is high.

  3. Transpiration is low and absorption of water is low.

  4. Transpiration is high and absorption of water is high.

Show answer
Correct Option: A

Choose the correct answers from the alternatives given.
Which of the following forces pushes water into the xylem as osmosis moves water into the root?

biology absorption by roots - the processes involved root pressure transportation in plants factors affecting the transport of water and minerals in plants

  1. Water stress

  2. Atmospheric pressure

  3. Root pressure

  4. Transpiration

Show answer
Correct Option: C
Explanation:

Root pressure that is developed in the roots pushes the water into the xylem which is then distributed to different plant parts required for growth.

Water stress is the condition that pushes water to the shoot system but root pressure is the force that required to push water upwards.
Hence,the correct answer is 'Root pressure'.

Choose the correct answers from the alternatives given.
Exudation

biology absorption by roots - the processes involved root pressure transportation in plants factors affecting the transport of water and minerals in plants

  1. Takes place during positive root pressure

  2. Takes place during negative root pressure

  3. Is unrelated with root pressure

  4. Is related with photosynthesis

Show answer
Correct Option: A
Explanation:

The exudation of liquid drops from the margin of the leaves is called guttation. This happens due to the development of high root pressure as a result of active or more absorption of water at night or early mornings and low transpiration rate. The positive pressure forces the liquid to come out through the special openings called hydathodes.

Hence, the correct answer is 'Takes place during positive root pressure'.

The most important forces for the ascent of sap in plants are?

biology absorption by roots - the processes involved root pressure transportation in plants factors affecting the transport of water and minerals in plants

  1. Imbibition and capillary

  2. Suction pressure and cohesion

  3. Capillary and root pressure

  4. Root pressure and pulsation

Show answer
Correct Option: C
Explanation:

  • The process by which water and minerals translocate from base to apex of the plant is known as the ascent of sap. It takes place through complex tissue xylem. Most important forces for the ascent of sap are; root pressure and capillary action.
  • Active transport of water takes place through xylem by a pressure called root pressure. It is responsible for pushing up water to small heights in the stem.
  • The tubes in the plant stem are very tiny and the movement of water through tiny tubes is called capillary action. This occurs when the adhesion is stronger than the cohesion. Water molecules are naturally attracted to each other. 


Hence, the correct answer is option C.

Match column I with column II and select the correct option from the codes given.

Column I Column II
A. Dixon and Jolly (i) Root pressure
B. Stomata (ii) Only water available to plants
C. Manometer (iii) Transpiration
D. Capillary water (iv) Transpiration pull
E. Potometer (v) Rate of transpiration
biology absorption by roots - the processes involved root pressure transportation in plants factors affecting the transport of water and minerals in plants

  1. A-(iv), B-(iii), C-(v), D-(ii), E-(i)

  2. A-(i), B-(iii), C-(iv), D-(ii), E-(v)

  3. A-(iv), B-(iii), C-(i), D-(ii), E-(v)

  4. A-(v), B-(iv), C-(iii), D-(ii), E-(i)

Show answer
Correct Option: C

Which pressure developed in the root, forces the water into xylem vessel and upwards into the stem for a certain height?

biology absorption by roots - the processes involved root pressure transportation in plants factors affecting the transport of water and minerals in plants

  1. Osmotic pressure

  2. Root pressure

  3. Atmospheric pressure

  4. Turgor pressure

Show answer
Correct Option: B
Explanation:
The pressure with which water is pushed into the xylem tubes of the root is called as root pressure. The water moving upwards forms a column, which is maintained up to a certain height due to root pressure.
In tall trees, trees, this type of absorption plays a minor role in transporting water. This process is slow, and it cannot make up for the water lost by transpiration (the evaporation of water from the leaves). Transpiration is rapid during the day.
The loss of water due to transpiration creates a suction force that pulls water up through the xylem vessels. This transpiration pull serves as the main force that transports water through the xylem. Root pressure helps in the transport of water at night.
So, the correct answer is option B.

Root pressure is retarded or become absent in

biology absorption by roots - the processes involved root pressure transportation in plants factors affecting the transport of water and minerals in plants

  1. Starvation

  2. Low temperature

  3. Drought

  4. All

Show answer
Correct Option: D
Explanation:

Root pressure is retarded or become absent under conditions of starvation, low temperature, drought and reduced availability of oxygen.