LabBench Activity

Measuring Dissolved Oxygen Under Varying Light Conditions

On the first day of the laboratory, you measure the amount of oxygen present in your original sample. You then measure the amount of oxygen present after 24 hours of photosynthesis and respiration under the light conditions in each bottle.

pipette Lab Hints

  1. The aquatic sample must be rich in photosynthetic organisms—water that is so algae-rich it appears green is good for this activity.
  2. Keep the water samples in a very bright light during the 24-hour period. Fluorescent bulbs do not give off much heat, but if you use an incandescent light bulb, you will need to place a heat sink (such as a beaker filled with water) between the light bulb and your bottles.