RBSE Class 11 Biology Notes Chapter 11 Transport in Plants

These comprehensive RBSE Class 11 Biology Notes Chapter 11 Transport in Plants will give a brief overview of all the concepts.

RBSE Class 11 Biology Chapter 11 Notes Transport in Plants

→ The plants obtain various inorganic elements (ions) and salts from their environment specially from air, water and soil. The movement of these nutrients from environment to plants and from one cell to other cell takes place essentially across the membrane through transport.

→ Transport in plants occurs on three levels

• cellular transport
• short distance transport and
• long distance transport.

→ There are three methods of transportation of substances-simple diffusion, passive diffusion and active diffusion.

→ Water and mineral salts absorbed by roots transported through xylem and food substances synthesized in leaves are transported through phloem.

→ Movement of particle or molecules from their high concentration to their low concentration is called diffusion.

→ During, diffusion, the diffusing particles exert a pressure which is called diffusion pressure (DP).

 

→ Permeability of membrane is a character through which any solute or solvent can pass in or out.

→ The membranes are of three types on the basis of permeability

1. permeable,
2. non-permeable and
3. semi-permeable.

→ Osmosis is a process in which, the molecules of solvent move from their higher concentration to the low concentration.
 
→ Osmosis is of two types-Exosmosis and endosmosis. On the basis of osmosis, the solutions are categorised into three types:

1. Hypotonic solution,
2. Isotonic solution and
3. Hypertonic solution.

→ The maximum. pressure, which is developed in a solution, when it is separated from its pure solvent by a semipermeable membrane (SPM) is called osmotic pressure (OP).

→ Osmotic pressure is'measured in atm.
Osmotic pressure = - osmotic potential (Ψ_s)

→ The pressure which is exerted on cellwall by protoplasm in a turgid cell is called turgor pressure (TP).

→ When the turgidity of cell increases, than cell wall exerts equal and opposite pressure, it is called wall pressure (WP).

→ The difference between the diffusion pressure of a solution and its pure solvent is called diffusion pressure deficit (DPD). It is also called suction pressure (SP).

→ Diffusion pressure deficit (DPD) of a solution is equal to its osmotic pressure. There is a wall pressure (WP) against turgor pressure (TP). Due to wall pressure, diffusion pressure increases but diffusion pressure deficit decreases.

→ When a cell is placed in a hypertonic solution then the water of protoplasm of cell diffuses into solution thereby the protoplasm shrinks, it is called plasmolysis.

→ The plants can absorb only capillary water from the soil by their roots.

→ The water remain in soil after permanent wilting of plant is called wilting coefficient or permanent wilting percentage.

→ Water absorption is of mainly two types:

• Active absorption: It requires energy.
• Passive absorption: It does not require energy.

→ There three theories are given related to ascent of sap:

• vital force theory,
• physical theory and
• root pressure theory.

→ The absorption of water by seeds and dry wood takes place through special diffusion, which is called imbibition.

→ Water, minerals and nutrients cannot enter into plant body by only diffusion, therefore they are transmitted by mass flow system.

→ The water absorbed from soil reaches to xylem through three ways:

• Apoplast pathway,
• symplast pathway and
• vacuolar pathway.

→ Different ions and water from soil transported in low height plants by root pressure. 

→ Transpiration pull is most accepted form of transportation of water.

→ The loss of water in the form of droplets from the margins of leaves is called guttation.

→ Plant part where food is synthesized is called source and where they consumed or stored is called sink.

→ Transport: The process of reaching water and food materials to different parts of plant body is called transport regional high concentration to lower concentration.

→ Diffusion: The movement of molecules or ions from the region of lower concentration is called diffusion.

→ Diffusion Pressure: The pressure developed as a result of the diffusing nature of molecules or ions of a substance is called diffusion pressure.

→ Facilitated Diffusion: Diffusion which takes place with the help of protein.

→ Symport: To across or transport the cell membrane in same direction by two types of molecules.

→ Antiport: To across or transport the cell membrane in opposite direction by two types of molecules.

→ Uniport: To across or transport the cell membrane freely by two types of molecules.

→ Active transport: The transport takes place using energy.

→ Water potential: The difference between the free energy of water molecules in pure water and that of water in any other system (e.g., water in a plant cell or in a solution) is termed as water potential.

→ Osmosis: Osmosis is a process in which two solutions of different concentrations are separated by a semipermeable membrane. The diffusion of water or solvent molecules takes place from the solution of lower concentration to the solution of higher concentration.

→ Endosmosis: Diffusion of water into the cell.

→ Exosmosis: Diffusion of water from cell.

→ Plasmolysis: Shrinkage of protoplasm, when cell is placed in hypertonic solution.

→ Deplasmolysis: When a plasmolysed cell is placed in hypotonic solution, the protoplasm regains its original position, it is called deplasmolysis.

→ Imbibition: The absorption of water or any other liquid by the solid particles of the substance without forming a solution is called imbibition.

→ Osmometer: The apparatus used to measure osmosis.

→ Diffusion Pressure Deficit: The difference between the diffusion pressure of a solution and its pure solvent is called diffusion pressure deficit.

→ Mycorrhiza: Symbiotic relation between plant root and fungi.

→ Velamen tissue: The tissue found in aerial roots to absorb moisture from atmosphere.

→ Ascent of sap: The process of reaching or movement of water to different parts of plant.

→ Cohesive force: The attraction force exerted between same molecules.

→ Transpiration: The loss of water from aerial parts of water vapour, is called transpiration.

→ Potometer: The aparatus used to measure the rate of transpiration.

→ Holard: The entire quantity of water present in soil is called holard.

→ Chresard: The quantity of water which is available to plants is called chresard.

→ Echard ; The quantity of water which is not available to plants is called echard.