Page 8 - E-Biology Sec.2 2024-2025 U1_Handy

a) Mechanism of water absorption

Permeability Imbibition Osmosis Diffusion
phenomenon phenomenon phenomenon phenomenon

b) Mechanism of mineral salts absorption

Diffusion Selective permeability Active transport
phenomenon phenomenon phenomenon

a)Absorption of water:

1. Permeability
phenomenon

The cell walls and their membranes differ in their permeability:

Permeable Impermeable Semi-permeable
Selectively permeable
Allow Don't allow
water & water and Allow passage of water.
salts ions salts ions to Control the passage of many salts.
to pass. pass. Prevent the passage of sugars and
Cellulose Walls of
lignin / a.a as they are large mol.
walls cutin / according to the cell requirements.
suberin
plasma membrane
"thin with tiny pores"

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First Term