what would explain the observed changes in net co2 exchange that occurred between days 3 and 4? question 2. how would you interpret the change in the daily patterns of co2 exchange during the period between days 4 and 10? hint: note in particular the changes in net co2 exchange during the night period, and see concept 5.3 in your textbook. question 3. what do you think is happening to net co2 exchange after the plant is again watered on day 10?