Biology Paper 1 - Required Practical - Osmosis And Effects On Plant Tissue

Question 1

Osmosis

Answer 1

Net movement of water particles from a dilute solution to a more concentrated solution across a partially permeable membrane.

Question 2

Methodology

Answer 2

• Use a cork borer to cut 3 cylinder pieces of the sample, using the same part of the tissue (the centre) and same variety (same shop/farm)
• Cut the pieces so that are the same length (around 3cm).
• Measure the mass/length of each cylinder and record.
• Place each cylinder into a test tube with different but known concentrations of salt/sugar.
• Leave for a sufficient amount of time (overnight)
• Remove the cylinders and pat/dab/roll gently of paper towel
  
  • Gently only to remove any excess surface water and not pull water out of tissue.
  • Excess water will make the result invalid.
• Re-measure length/mass of tissue.

Question 3

Percentage Change

Answer 3

% Change = Change in value / Original Value.