Differentiate between the following: (a) Diffusion and Osmosis (b) Transpiration and Evaporation (c) Osmotic Pressure and Osmotic Potential (d) Imbibition and Diffusion (e) Apoplast and Symplast pathways of movement of water in plants. (f) Guttation and Transpiration. | NCERT solution | Class 11 Biology | Unit-11 Transport in Plants



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Q.5:- Differentiate between the following:

(a) Diffusion and Osmosis
(b) Transpiration and Evaporation
(c) Osmotic Pressure and Osmotic Potential
(d) Imbibition and Diffusion
(e) Apoplast and Symplast pathways of movement of water in plants.
(f) Guttation and Transpiration.

Answer:- 

(a) Diffusion and Osmosis

Diffusion
Osmosis
It is a movement of molecules from high concentration to low concentration. It is a movement of molecules from high concentration to low concentration through semi permeable membrane.
It can occur in solids, liquids, and gases. It occurs in the liquid medium.
It does not require any driving Force. It occurs in response to a driving force.
OR
Osmosis is a type of diffusion. When diffusion happens across a semi-permeable membrane, it is called osmosis. Semi-permeable membrane is not necessary in all cases of diffusion.

 

 

(b) Transpiration and Evaporation
Transpiration
Evaporation
It occurs in plants. It occurs from any free surface and involves living and non-living surfaces.
It occurs mainly through the stomatal pores on plant leaves. It occurs through any free surface.
It is controlled by environmental factors as well as physiological factors of plants It is entirely driven by environmental factors.
OR
Evaporative loss of water from plants is called transpiration, while conversion of water into vapour at any temperature is called evaporation.

 

 

 

(c) Osmotic Pressure and Osmotic Potential

Osmotic Pressure
Osmotic Potential
It is expressed in bars with a positive sign. It is expressed in bars with a negative sign.
It is a positive pressure. It is a negative pressure.
Its value increases with an increase in the concentration of solute particles. Its value decreases with an increase in the concentration of solute particles.
OR
The pressure which needs to be applied to prevent the inward flow of water across a semi-permeable membrane. In other words, the minimum pressure needed to negate the osmosis is called osmotic pressure. On the other hand, the ability of a solution to suck in water from across a semi-permeable membrane is called osmotic potential.

 

 

 

(d) Imbibition and Diffusion



Imbibition
Diffusion
Imbibition is a special type of diffusion when water is absorbed by solids and colloids causing them to enormously increase in volume. Diffusion is the passive movement of particles, ions, and molecules along the concentration gradient.
It usually involves water. It involves solids, liquids, and gases.
OR
Random movement of molecules to attain concentration equilibrium is called diffusion. When osmosis happens in a way that solids (colloids) take up water, it is called imbibition.

 

 

 

(e) Apoplast and Symplast pathways of movement of water in plants.

Apoplast pathways
Symplast pathways
It is the system of adjacent cell walls that is continuous throughout the plant, except at the casparian strips of the endodermis in the roots It is the system of interconnected protoplasts.
Water moves through the intercellular spaces and the walls of cells Water travels through the cytoplasm of cells and intercellular movement is through plasmodesmata.
It is a faster process of water movement and water moves through mass flow. It is a slower process of water movement.

 

 

 

(f) Guttation and Transpiration.

Guttation
Transpiration
It occurs through the vein endings of leaves. It occurs through the stomata.
Water is lost from the leaves in the form of liquid droplets. Water is lost from the leaves in the form of water vapour.
It occurs usually at night. It occurs usually during the day.
It is regulated by humidity, temperature and presence of water in soil. It is regulated by a number of external and internal factors such as relative humidity, temperature opening and closing of stomata, etc.
OR
Exudation of water from smaller plants; under low evaporation conditions; is called guttation. Evaporative loss of water from plants is called transpiration. In guttation, water comes out in liquid form; while in transportation, water comes out in gaseous form.
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