Biology Portion

 Created and Conducted by: Emily Basara and Samantha Jones

Research Question: What is the effect of the presence of the chemical Sodium Bicarbonate (NaHCO3) on the amount of oxygen or photosynthetic output released by the aquatic plant, Cryptocoryne wendtil over time, and how does the variation of this effect show the effectiveness of the filtration process?

Hypothesis: The presence of the chemical Sodium Bicarbonate would increase the amount of oxygen or photosynthetic output released by the aquatic plant, Cryptocoryne wendtil. Also, the more the time the plant stays in the environment, the more oxygen will be released. This is predicted due to the fact that plants produce oxygen over time and Sodium Bicarbonate can increase oxygen levels. Similarly, the filtered solution is projected to display a median oxygen level, assuming the filtration process affected the presence of Sodium Bicarbonate in the sample procured.

Materials:

• Three 40 mL beakers
• One 100 mL beaker
• Distilled water
• Tap water
• Sodium Bicarbonate chemical solution
• Sodium bicarbonate chemical solution, filtered
• Three 2 inch stem and root segments of the aquatic plant Cryptocornye wendtil
• Dissolved Oxygen Probe
• Timer
• Thermometer

Variables:

Independent Variable	Dependent Variable	Controlled Variables
Presence of Sodium Bicarbonate	The amount of oxygen present (measured in milligrams per liter)	Temperature of the solution (would be the average room temperature 23 °C)
The amount of time the plant was in the solution (10 minutes, 20 minutes, 30 minutes)		The amount of each solution used (100 mL)
		The amount of the plant that was used (approximately 8 leaves with stems (1.0-2.4 grams)
		The type of each solution used (Distilled water, tap water, presence of Sodium Bicarbonate)
		The amount of time that has passed (recording every 10 minutes for 30 minutes)

Procedure:

1.  The 100 mL beaker was filled with distilled water.
2. The Dissolved Oxygen Probe was warmed up and calibrated in the beaker of distilled water for ten minutes.
3. The three 40 mL beakers were filled with tap water, Sodium Bicarbonate solution, and the filtered solution, respectively. 
4. The Dissolved Oxygen Probe was used to determine the amount of dissolved oxygen in each sample. Results were recorded. 
5. Each of the three 2 inch segments of the aquatic plant Cryptocornye wendtil was assigned a sample and were submerged. 
6. After ten minutes as recorded by a timer, the Dissolved Oxygen Probe was used to determine the amount of dissolved oxygen in each sample. Results were recorded. 
7. After ten more minutes as recorded by a timer, the Dissolved Oxygen Probe was used to determine the amount of dissolved oxygen in each sample. Results were recorded. 
8. After ten minutes as recorded by a timer, the Dissolved Oxygen Probe was used to determine the amount of dissolved oxygen in each sample. Results were recorded. 

 Data:

                                                             Group 4 Biology Data

Tap Water (Without Plant)

Tap Water (With Plant)

Chemical Solution (Without Plant)

Chemical Solution (With Plant)

Filtered Solution

Filtered Solution

(Without Plant)

(With Plant)

Time (in  minutes)

10 min

4.1 mg/L

4.7 mg/L

5.1 mg/L

5.4 mg/L

5.1 mg/L

5.3 mg/L

20 min

4.0 mg/L

4.9 mg/L

5.1 mg/L

5.6 mg/L

5.0 mg/L

5.5 mg/L

30  min

4.1 mg/L

5.1 mg/L

5.2 mg/L

5.9 mg/L

5.1 mg/L

5.7 mg/L

Approximate Mean

4.1 mg/L

4.9 mg/L

5.1 mg/L

5.6 mg/L

5.1 mg/L

5.5 mg/L

Approximate Standard Deviation

0.06 mg/L

0.2 mg/L

0.06 mg/L

0.3 mg/L

0.06 mg/L

0.2 mg/L

Conclusion:
In conclusion, the results and data were expected and followed the initial hypothesis precisely. However, when the chemical solution was filtered, there was more oxygen present. This may have been due to oxygen being present upon the rocks and materials used during the filtration of the liquid when the Physics portion of the project/experiment was conducted. All in all, however, the change in oxygenation prior to and including the addition of the aquatic plant Cryptocoryne wendtil changed very similarly in all three samples. This indicates that the filtration system showed no significant difference in the rate of the photosynthetic output of the plant. This could signify a limited experiment- and there were, indeed, issues within the experiment that could indicate a potential for error- but it is also possible to conclude that the filtration system was neither a hindrance nor a help to the welfare of the vitality of the aquatic plant.
Evaluation:

•  It was assumed that the oxygen probe was still functional despite how many years it spent in the school with the starter solution within it. There could be a considerable amount of error from this. 
• It was assumed that the amount of the plant Cryptocoryne wendtil used for each solution was sufficient in terms of releasing a significant amount of oxygen that could represent the photosynthetic output of the plant.
• Another assumption was that one plant sample of Cryptocoryne wendtil was capable of representing the photosynthetic output of the type of plant as a whole. The results applied only to one sample of the plant and may be inaccurate due to that.

Improvements:

• The experiment was somewhat affected by issues with calibration in the Dissolved Oxygen Probe. Separate trials were performed out of necessity due to a filter malfunction, and the calibration was difficult to match up. Due to this, some results could potentially be skewed due to technological issues with the Dissolved Oxygen Probe. To rectify this, the experiment should be kept within a certain time frame and performed only when the final filtered solution is available in order to prevent extraneous readings from the Dissolved Oxygen Probe. 
• A leafier variety of aquatic plant could be used in place of the Cryptocoryne wendtil in order to provide more surface area for photosynthesis
• Perhaps the amount of  Cryptocoryne wendtil used could have been measured more accurately as the scale had issues reading the weight of the amount of the plant used.

Implications:

• Plants could help increase the oxygen content of many liquid solutions over time. This would imply that plants could help add oxygen to water sources that need more oxygen- therefore it may be used to save aquatic life.
• Implies that there is a economically sound method of adding oxygen to water and could be ethically sound as it could help with the survival of aquatic life. However, plants could die in such environments. Overtime, this method may not work in water that has been polluted to the point that plant life cannot survive. 
• The welfare of plant life is often at risk due to pollutants in the water. This experiment proved that this particular type of filter was less than successful, which could rule it out as an object of pollution control.