Cohesion

Q.

Explain transport of water and minerals in plants.

Q. The pressure developed in the root xylem due to entry of water followed by the active transportation of mineral ions is called -

1. Root pressure

2. Wall pressure

3. Turgor pressure

4. Osmotic pressure

Q.

Explain the term root pressure.

1. The pressure in plants helps to drive fluids upward into the water-conducting vessels (xylem).

2. The pressure in which water is pulled upwards due to the suction force created by transpiration.

3. The pressure in which the roots push into the soil in search of water and minerals.

4. The pressure that forces food from the stems into the root, via the phloem is called root pressure.

Q.

What is meant by active transport of minerals in plants?

Q.

Who Discovered Guttation?

Q.

Identify the correct statements related to the uptake of mineral ions

A. The membrane proteins pump ions from soil into the cytoplasm of epidermal cells

B. Transport proteins of endodermal cells act as control points, which adjust the quantity and type of solutes reaching the xylem

C. Root endoderm due to its suberin layer, can not transport ions

1. A & C

2. A, B & C

3. A & B

4. B & C

Q.

Name the following:

Pressure developed in the roots due to continuous inward movement of water.

Q.

Define cohesion.

Q. Differentiate adhesion and cohesion of water molecules during their transport in plants

Q. Prolonged water-logging kills plants due to

1. Leaching of nutrients
2. Dilution of soil nutrients
3. Dilution of plant cell sap
4. Stoppage of root respiration

Q.

Please explain me the concept of root pressure in detail.

Q.

The figure given below is a diagrammatic representation of a part of the cross section of the root in the root hair zone. Study the same and then answer the questions that follow:

(i) Name the parts indicated by the guidelines 1 to 4.

(ii) Which is the process that enables the passage of water from the soil into the root hair?

(iii) Name the pressure that is responsible for the movement of water in the direction indicated by the arrows. Define it.

Q. Choose the correct answers from the alternatives given :
In which of the following plants metabolism would be hindered if leaves are coated with vaseline on their upper surface ?

1. Pistia
2. VaIlisneria
3. Lotus
4. Mango

Q. Active absorption of water by roots from the soil is mainly affected by

1. Tension in cell sap due to transpiration.
2. Hydrophobic nature of root hair.
3. Osmotic concentration of xylem sap.
4. Typical tissue organisation.

Q. Water potential of root cells is higher than water potential of soil.

1. True
2. False

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

1. Temperature
2. Light
3. Humidity
4. Nitrogen content in the soil

Q. Explain manifestation of root pressure

Q. Osmotic theory of active water absorption was given by

1. Keller
2. Bennet-Clark et al
3. Atkins
4. Kramer

Q.

Explain how the bond formation take place in ribosome??

Q. Cohesive force of water molecules is of the magnitude of

1. 15 - 45 atm
2. 45 - 200 atm
3. 10 - 15 atm
4. 1 - 10 atm

Q.

Which of the following contributes most to transport of water from the ground to the leaves of a tall tree?

1. Cohesion of water

2. Transpiration pull

3. Root pressure

4. Capillary rise of water in xylem

Q.

what is happens when -

1)methylene stain is added to cheek cell

2)rheo leaves are boiled in water and a drop of sugar syrup is added to it

3)RBCs are kept in concentrated solution

Q. When concentration of solute is low in plant cell, absorption of water is

1. Absent
2. Retarded
3. Increased
4. Normal

Q.

Molecules of water are held together by hydrogen bonds.This mutual intermolecular attractive force is called _______.

1. cohesive force

2. capillarity

3. imbibition

4. adhesive force

Q. The mutual attraction between water molecules is called while is the attraction of water molecules to the surface.

1. osmosis
2. cohesion
3. capillarity
4. adhesion
5. transpiration

Q. Which of the plants can absorb water in the form of vapour from its atmosphere?

1. All xerophytes
2. Low transpiring cacti
3. Succulent plants
4. Epiphytes and lichen

Q. Force for passive water absorption develops in

1. Xylem
2. Aerial parts
3. Root
4. Root hairs

Q.

Molecules of water are held together by hydrogen bonds.This mutual intermolecular attractive force is called _______.

1. adhesive force

2. cohesive force

3. capillarity

4. imbibition

Q. Rate of water absorption is slow near freezing point because

1. Water absorption is a metabolic process
2. Cell growth stops
3. Transpiration is reduced
4. Cell membrane become more viscous

Q. The phenomenon related to active water absorption is

1. Translocation
2. Osmotic pressure
3. Transpiration
4. Root pressure