Watching Osmosis

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Lesson 3

• Watching Osmosis

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Water movement in plant cells
You should already know from previous lesson
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Investigation Method
Adistilled water
C strong sugar solution
B weak sugar solution
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Investigation into plant cells

• Fair test
• 1. Same size chip
• 2. Same volume of solution
• 3. Same duration for investigation
• 4.Same type of potato
• Variable
• Concentration of immersion solution

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You will need to record the following
observations for each concentration

• 1. Length of chip
• 2. Mass of chip
• 3. Volume of solutions
• 4. Firmness of chip

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Results of investigation
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(No Transcript)
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Work to do in your book

• Aim
• to observe observe osmosis in living tissue
• Prediction What do you think will happen to the
  potatoes in each of the 3 tubes. Give reasons
  for your predictions.
• Results
• Record in a table
• Conclusion
• 1. In which solution was there the greatest
  change in mass?
• 2.In which tube was there the greatest change
  in appearance?
• Explain how these changes happened. Describe
  the movement of water in each of the 3 tubes.
• Evaluation
• Describe any improvements to this method.

Apparatus Draw labelled diagrams
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Conclusion

• What happened
• Distilled water
• Increase in mass and length Firm and turgid
• Strong sugar
• decrease in mass and length
• Soft and floppy, flaccid
• Weak sugar
• Increase /decrease

• Why it happened
• Water particles moved
• into chip from outside
• Water particles moved
• out of chip into beaker
• Depends on concentration
• of water inside potato

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A turgid plant cell
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Plasmolysis
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Osmosis in plant cells
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Water movement into root hair cells
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Osmosis in a red blood cell
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Osmosis in animal cells summary