Cohesion

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.

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.

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. Osmotic theory of active water absorption was given by

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

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. The phenomenon which forces water upwards into tracheary elements of xylem in the root region is

1. Root pressure
2. Turgor pressure
3. Imbibition pressure
4. Transpiration

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. 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. 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