Required Practical 2-Effects of osmosis on plant tissue

• What should you be able to describe by the end of the video?

  How to investigate osmosis on plant tissue
• What is osmosis?

  Diffusion of water through a membrane
• What happens to plant cells in water?

  Water moves in, causing cells to expand
• What occurs when plant cells are placed in a concentrated solution?

  Water moves out, causing cells to shrink
• What 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 borer
• What length should the potato cylinders be trimmed to?

  Approximately three centimeters
• Why is it important to use cylinders of the same diameter?

  To ensure consistent surface area for osmosis
• What is the first step after preparing the potato cylinders?

  Measure the length and mass of each cylinder
• What volume of sugar solution is added to the first test tube?

  10 centimeters cubed
• What concentration of sugar solution is used in the first test tube?

  0.5 molar
• What type of water is used in the third test tube?

  Distilled water
• Why is distilled water preferred over tap water?

  It contains no dissolved substances
• What should be done after leaving the potato cylinders overnight?

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

  To avoid forcing water out of the cells
• What measurements are taken after removing the potato cylinders?

  Length and mass of the cylinders
• How is percentage change calculated?

  Change in value divided by original value
• What is the formula for calculating percentage change?

  Percentage change = (change/original) * 100
• If a potato cylinder has a starting mass of 1.56 grams and increases by 0.25 grams, what is the percentage change?

  +16.03 percent
• If a potato cylinder has a starting mass of 1.32 grams and decreases by 0.19 grams, what is the percentage change?

  • 14.39 percent
• What does the graph of percentage changes in mass or length show?

  Mass gain in water, loss in concentrated solution
• What does it mean when the graph crosses the x-axis?

  No change in mass occurs
• What does the concentration at the x-axis crossing indicate?

  Approximate concentration inside the cell
• What should you learn for the exam regarding this practical?

  Details of investigating osmosis and calculations
• What is the importance of osmosis in plant cells?

  It regulates water balance and cell turgor
• What role does a partially permeable membrane play in osmosis?

  It allows water to pass while blocking solutes
• How do different concentrations of sugar solutions affect osmosis?

  Higher concentrations cause more water to leave cells
• Why is measuring both length and mass significant in the experiment?

  To assess the effect of osmosis accurately
• Why is consistency in experimental conditions important?

  To ensure valid and reliable results
• What does the concept of equilibrium in osmosis refer to?

  Equal concentration of solutes inside and outside
• What are the implications of osmosis in agriculture?

  It affects plant hydration and growth