structure of root

funtions

fix the plant to the soil

absorb water & minerals

conduct absorbed substances to the upper parts

adaptations

• branching & provides a large SA
• unicellular root hair by which substances enter the plant
• thing freely permeable membrani of root hair allows for diffusion
• semi permeable membrane allows for osmosis

imbibition

the phenomenon by which living or dead cells of plant in their dry state absorb water by surface attraction

• helps in uptake of soil water by root hairs
• imbibition pressure helps in the ascent of sap

diffusion

movement of gases or disolved substances in solution from their region of higher concentration to lower concentration

active transport

it is the forced movement of solvents from their region of low concentraiton to high concentration

• mineral radicals are transported from the soil to the root hair

  

osmosis

movement of solvent molecules across a semipermeable membrane from its area of high concentration to area of lower concentration

osmotic pressure- pressure exerted by the liquid column which just prevents the entry of the solvent molecules

osmotic potential- capacity of a solution ot relase molecules.

• what is the significance of osmosis in plants?
• what is the significance of osmosis in animals?
• why does a body of a marine fish often burst in tap water?

endosmosis

the inward movement of solvent particles through the semi permeable membrane

exosmosis

the outward movement of solvent particles through the semi permeable membrain.

types of solutions

• isotonic- both have the same osmotic potential at the same temperature
• hypotonic- lower concentration of solute molecules [dilute solution]
• hypertonic- high concentration of solute molecules [concentrated solution]

turgidity & turgor pressure

turgidity- when the walls are in a state of tension

turgor pressure- it is the outward pressure exerted by the fluid contents on the walls

• a cell no longer charged with water is termed as flaccid
• what is the significance of turgidity?

plasmolysis

the shrinkage of the cell membrane & the content of the cell away from the cell wall

deplasmolysis

the return of a plasmolysed cell when it is placed in a hypotonic solution