1. The Effect of Light Wave Length on Algae Growth
Clay Wyda
Grade 9
Pittsburgh Central Catholic

2. Light Spectrum
Visible light has moderate wavelength and energy. Life has adapted to make use of or resist this radiation
Explain the visible light spectrum

3. Photosynthesis
Photosynthesis takes place in organelles called chloroplasts.
light-dependent reactions occur in the thylakoid membranes of the chloroplasts and use light energy to synthesize ATP and NADPH.
Euglena utilizes chloroplasts, containing Chlorophyll a, Chlorophyll b, and some carotenoid pigments

4. Photosynthesis
chlorophyll is much more efficient at using the red and blue spectrums of light to carry out photosynthesis.

5. Euglena Common algal like protist Extremely tolerant of many habitats
Capable of survival in both salt and water environments
Uses a flagella for movement in its environment
A partial heterotroph- can attain food through endocytosis and photosynthesis

6. Purpose
To determine which spectrum of light euglena algae grows best in.

7. Hypothesis
Null- algae growth will not vary significantly when exposed to varying colors (wavelengths) of light.
Alternate – Algal growth will vary significantly when exposed to different light colors.

8. Materials Fifty 13 x 100 borosilicate culture test tubes
50 ml of Euglena gracilis algae
Pipettes and a Pipette pump
5 60watt light bulbs
4 light screens(red, blue, green, yellow)
5 test tube racks (that do not cover the sides of the test tubes)
Spectrophotometer (Science Kit Educator)
100 ml of soil water
100 ml of spring water

9. Procedure Mixed the following ingredients into test tubes:
2ml Spring water
2ml Soil water
1ml Euglena
Placed 10 tubes in each rack
10 tubes in the first row
The racks were placed approximately 23 cm. away from the edge of the table

10. Procedure A light bulb was placed at the end of the table 20 cm up
It was then angled at 45° toward the Algae
The distance from the light to algae was 30 cm
A screen was placed over top of the light bulb for 4 of the 5 bulbs (one was without a screen)
Next the algae was exposed for 8 hours a day to the lights.
Absorbance readings were taken every 3 days with a Spectrophotometer set to the wave length 430 nm for 18 days

12. Results
Anova: Single Factor for Day 22
SUMMARY
Groups
Count
Sum
Average
Variance
Column 1 5
0.658
0.1316
Column 2
0.826
0.1652
0.0003
Column 3
0.818
0.1636
Column 4
0.754
0.1508
Column 5
0.683
0.1366
2.23E-05
ANOVA
Source of Variation SS df MS F
P-value
F crit
Between Groups 4
Within Groups 20
Total 24
The results of the anova show that there was significant variation between the groups. This is because the P-value is less than 0.05

13. Dunnetts’ test- Day 22 Color T- value T-crit Red 2.327 2.23
Significant
Green
-0.431
Insignificant
Blue
2.491
Yellow
1.224

14. Conclusion Null – all light will have the same effect – Rejected
The hypothesis that algae exposed blue light will grow the best and that the algae exposed to green light will do the worst. – Accepted

15. Limitations and Extensions
Algae was not kept at the same temperature each day
Weather variations could have small effects of data
Algal cultures might not have been in optimal health
Extensions
Greater sample sizes.
Algal health- the study will be repeated using a fresh culture and a longer period of observation

16. Sources
Campbell, Neil A. and Reece, Jane B Biology Eighth Edition. Pearson Benjamin- Cummings. San Francisco, CA
Vliet, Kent A A Lab Manual for Integrated Principles of Biology Part one- BSC2010L Forth Edition. Pearson Custom. University of Florida.