Plant -Water Relations
Chapter Name : Transport In Plants |
Sub Topic Code : 103_11_11_02_02 |
Topic Name : Plant -Water Relations |
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Sub Topic Name : Osmosis |
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Introduction
Osmosis is the diffusion of water molecules from low concentration to higher concentration across a semi-permeable membrane.
Pre-Requisites:
• Structure of plant cell. • Semi-permeable membrane, concentration and pressure gradient.
Activity:
Make a potato osmometer by making a cavity in potato and filling sugar solution in cavity and place this in water. See the accumulation of water in the cavity due to osmosis
Real Life Question:
Does osmosis play a role in survival of fishes in sea water?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Osmosis | Movement of water molecules across a semi-permeable membrane from region of lower to higher concentration. |
| Plant cell components | Cell membrane, vacuole membrane and tonoplast are important in movement of molecules. |
| Osmotic pressure | The pressure required to prevent water from diffusing and is the function of solute concentration. It is the positive pressure. |
| Osmotic potential | Numerically osmotic potential is equal to osmotic pressure but osmotic potential is negative. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Observe plant cell under microscope. | Try to look out for cell components important in osmosis. |
Real life uses :
Plant roots take up water for survival from the soil by osmosis.
Places to visit :
Biology Laboratory.
Practical examples around us
| Examples | Explainations |
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What you learn in Theory:
Movement of water molecules in plants by osmosis.
What you learn in Practice:
How water is transported to different parts of the plant.