Required Practical: Effects of Osmosis on Plant Tissues

• What happens to plant cells placed in water?

  Water moves into the cell, causing expansion
• What occurs when plant cells are placed in a concentrated solution?

  Water moves out, causing cell shrinkage
• What type of vegetable is commonly used to investigate osmosis?

  Potato
• Why do we peel the potato before the experiment?

  The skin can affect osmosis
• What tool is used to produce potato cylinders?

  Cork board
• Why do we trim the potato cylinders to the same length?

  To ensure consistent measurement of osmosis
• What is a good length for the potato cylinders?

  Three centimeters
• What do we measure before placing the potato cylinders in the solution?

  The length and mass of each cylinder
• How much of the sugar solution is added to the first test tube?

  10 centimeters cubed
• Why do we use distilled water instead of tap water?

  Distilled water has no dissolved substances
• What should we do after leaving the potato cylinders overnight?

  Gently roll them on paper towel
• Why is it important not to press on the cylinders?

  To avoid forcing water out of the cells
• What do we measure again after removing the potato cylinders?

  The length and mass of the cylinders
• What are the steps to investigate the effect of osmosis on plant tissue?

  1. Peel the potato.
  2. Use a cork board to create cylinders.
  3. Trim cylinders to the same length.
  4. Measure length and mass of each cylinder.
  5. Place cylinders in different sugar solutions.
  6. Leave overnight for osmosis to occur.
  7. Remove and roll on paper towel.
  8. Measure length and mass again.
  9. Calculate percentage change.
• What is the equation for calculating percentage change?

  Percentage change = (Change in value / Original value) × 100
• What are the effects of osmosis on potato cylinders in different solutions?

  • In water: Gains mass (water enters)
  • In concentrated sugar solution: Loses mass (water exits)