Paper 1- 2021

• Tissue fluid is formed from blood at the arteriole end of a capillary bed.

  Explain how water from tissue fluid is returned to the circulatory system.

  Plasma proteins remain

  Water potential gradient created

  Water moves to blood by osmosis.

  Returns to blood by lymphatic system.
• The student wanted to use the data from plot 1 to estimate the total number of the beetle species in the meadow.

  Suggest how the student should use the data from plot 1 and other information provided to estimate the total number of the beetle species in the meadow.

  determine area of plot 1

  calculate total area of meadow

  divide area of meadow by area of plot.

  multiply by number of beetles.