Question

A flask containing photosynthetic green algae and a control flask containing water with no algae are both placed under a bank of lights that is set to cycle between 12 hours of light and 12 hours of dark. The dissolved oxygen concentrations in both flasks are monitored. Predict what the relative dissolved oxygen concentrations will be in the flask with algae compared to the control flask. The dissolved oxygen in the flask with algae will ________.

a) always be higherb) always be lowerc) be the same as the control in the light or darkd) be higher in the light, but lower in the dark

Answer 1

In the flask with algae, there would be photosynthesis in the presence of light which uses up the oxygen hence the dissolved oxygen in the flask with algae will be higher in the light but lower in the dark.