## Part B

Collecting Data

### 6. Create a data table like the one below.

7. Record that there was 0 mm gas in the test tube on day 0. (If you were unable to place the test tube without getting air in the tube, measure the height of the column of air in the test tube in millimeters. Record this value for day 0.) In this lab, change in gas volume is indicated by a linear measurement expressed in millimeters.

8. For days 1 through 5, measure the amount of gas in the test tube. Record the measurements in your data table under the heading "Total amount of gas present (mm)."

9. Calculate the amount of gas produced each day by subtracting the amount of gas present on the previous day from the amount of gas present today. Record these amounts under the heading "Amount of gas produced per day (mm)."

Analysis and Conclusions

1. Using the data from your table, prepare a graph.

2. Using information from your graph, describe what happened to the amount of gas in the test tube.

3. How much gas was produced in the test tube after day 5?

4. Write the equation for photosynthesis. Explain each part of the equation. For example, which ingredients are necessary for photosynthesis to take place? Which substances are produced by photosynthesis? Which gas is produced that we need in order to live? 5. What may happen to the oxygen level if an animal, such as a snail, were put in the beaker with the elodea sprig while the elodea sprig was making oxygen?

Further Inquiry

Design an experiment for predicting the effects of temperature on the amount of oxygen produced or rate of photosynthesis by elodea. 