PLANT WATER RELATION

PLANT WATER RELATION 

Root: The descending underground part of the plant which helps in absorption of water and mineral from the soil is called root.

Velamen: The outer layer of empty cells of epiphyte which helps in absorption of water directly from the atmosphere.

Root hairs: The epidermal cells at the region of elongation form unicellular hair-like extensions called root hairs.

Ephemeral: Something which last for a very short period of time is called ephermal.   

Rhizosphere: The region of soil which is directly influenced by the secretion of root and soil microorganisms are known as the rhizosphere.

Gravitational water: The water which percolates deep into the soil due to the gravity is called gravitational water.

Hygroscopic water: The water adsorbed from the atmosphere by the fine soil particles is called hygroscopic water. 

Combined water: The Water present in the form of hydrated oxides of silicon, aluminium, etc. is called combined water.

Capillary water: The water which is held into the pores of the soil is called capillary water.

Imbibition: The swelling up of hydrophilic colloidal substance due to the adsorption of water is called imbibition.

Imbibant: The Substance that adsorbs water is called as imbibant.

Imbibate: The water that gets imbibed is called as imbibate.

Osmosis: The movement of solvent from lower concentration to the region of higher concentration through the semipermeable plasma membrane is called Osmosis.

Hypotonic solution: The weak solution or the strong solvent having low osmotic concentration is called a hypotonic solution.

Hypertonic solution: The strong solution or the weak solvent having high osmotic concentration is called a hypertonic solution.

Isotonic solution: The solution having the same concentration outside and inside the cell is called an isotonic solution.

Exo-osmosis: The migration of solvent out of the cell is called Exo-osmosis.

Endo-osmosis: The migration of solvent into the cell is called Endo-osmosis.

Turgidity: Due to the endosmosis cell becomes fully stretched, such stretched cells are called turgor cells and the process is called turgidity.

Turgor pressure: The pressure exerted by the osmotic flow of water into the inner wall of the cell is called turgor pressure.

Wall pressure (W. P.): The counter pressure exerted by inner wall of the cell on the cell sap is called Wall pressure (W. P.).

Osmotic pressure (O. P.): The pressure exerted during the process of osmosis is called osmotic pressure.

Facilitated diffusion: The passive absorption of solutes facilitated by transmembrane integral protein is called facilitated diffusion.

Water Potential (ψ): The chemical potential of water is called water potential.

  

Chemical potential: Free energy per molecule in a chemical system is called its chemical potential.

Plasmodesmata: The cytoplasmic bridge between the adjacent cells is called plasmodesmata.

Plasmolysis: Exo-osmosis in a living cell when placed in hypertonic solution as a result the cell becomes flaccid is called plasmolysis.

Deplasmolysis: Endo-osmosis in a living flaccid cell when placed in a hypotonic solution, as a result, the cell regains its actual size and the shape is called deplasmolysis.  

             

Apoplast: the movement of water across the root through the cell wall and the intercellular spaces of cortical cells are called the apoplast pathway.

Symplast: Movement of water from one living cell to another living cell through a cytoplasmic bridge is called the symplast pathway.

Plasmodesmata: The cytoplasmic bridge between two living cells is called plasmodesmata.

Casparian strip: The band of endodermal cells containing suberin which can resist the entry of water is called Casparian strip.

             

Passive absorption: The absorption of water without the expenditure of energy in which roots are not actively involved is called passive absorption.

Active absorption: The absorption of water with the expenditure of energy in which root and root cells are actively involved is called active absorption.

Translocation of water: The transport of water with dissolved minerals from the root to other aerial parts like stem and leaves, against the gravity, is called translocation or ascent of sap.

Cohesion: The attraction between the similar particles are called cohesion.

Adhesion: The Attraction between the dissimilar particles are called Adhesion.

Transpiration: Loss of water from the plant body in form of water vapour is called transpiration.

Macro elements: The minerals like C, H, O, P, N, S, Mg required in large quantity, are called macro elements.

Micro elements: The minerals like Cu, Co, Mn, B, Zn required in small quantity, are called microelements.

Chloroplasts: The type of plastid which acts as a site of photosynthesis is called the chloroplast.

Source: The part of the plants where food is synthesized is called source.

Sink: The part of the plants where the food is utilized is called a sink.

Vertical translocation: The translocation of food in the downward direction from leaves (source) to stem and root (sink) is called vertical translocation.

Lateral translocation: The translocation of food in the root and stem is called lateral translocation.

Lateral translocation: Translocation of food from phloem to pith is called radial translocation.

Tangential translocation: Translocation of food from phloem to cortex is called tangential translocation.

Guttation: The loss of water in the form of liquid is called guttation.

Cuticle: The waxy layer present on the outer surface of epidermal cells of leaves and stem are called a cuticle.

Stomata: The tiny opening present on the surface of green parts of the plants are called stomata.

Lenticels: The small raised structures which are composed of loosely arranged complementary cells are called lenticels.

Epistomatic leaf: The leaf having stomata on upper epidermis only is called epistomatic leaf E.g. Lotus.

Hypostomatic leaf: The leaf having stomata on lower epidermis only is called hypostomatic leaf E.g. e.g. Nerium.

Amphistomatic: The leaf having stomata on both the surfaces are called an amphistomatic leaf.

Stomatal frequency: The number of stomata per unit area of the leaf is called stomatal frequency.

Stomatal index (I).The correlation between the number of stomata and the number of epidermal cells per unit area is called stomatal index (I).

Accessory cells: The specialized epidermal cells surrounding the guard cells are called accessory cells. These are also called subsidiary cells.

Osmolarity: Total number of solute particles present in per litre of a solvent is called osmolarity.