LABORATORY 4: Exercise 4 Answers

• If you conducted the experiment in the dark would you expect different results?

  There would be no difference. None of the tissue of the germinating seeds is actively photosynthetic at the stage used.

• How could you prove that Carbon dioxide is given off during respiration?

  You could pump the gas produced in to a solution of Barium Hydroxide (see exercise 2)

• Which respired more rapidly, the seeds or the flour worms?

  The flour worms due to the more active life and the greater proportion of active cells per unit of mass.

• How would changes in environmental temperature (in either an upward or a downward direction) affect respiration in a homeothermic animal?

  A homeothermic animal will need to expend energy to keep itself warm or to cool itself.

• Name the specific regions of a cell where the various steps of catabolism takes place.

  Glycolysis - in the cytoplasm
  Krebs Cycle - matrix of the mitochondrion
  Electron Transport Chain - Inner membrane (cristae) of the mitochondrion