Effect of Varying Light Intensity on the Photosynthetic Rate of Wild Type and Mutant Chlamydomonas reinhardtii

Abstract

Chlamydomonas reinhardtii is a species of photosynthetic green alga that has many different mutant strains that are readily available for experimental study. The purpose of our study was to measure the amount of oxygen produced by the wild type C. reinhardtii and by the immobile mutant strain CC-3913-pf9-3, during photosynthesis at different light intensities. Three replicates of both wild type and mutant cells were placed at 0-watt, 60-watt, 100-watt, and 150-watt treatment levels for one hour and oxygen levels were measured before and after the replicates were exposed to the different light levels. The wild type trials showed a statistically significant difference in oxygen production between all four treatment levels (0-watt 5.57 +/-0.06 mg/L of 02, 60-watt 6.40 +/-0.10 mg/L of 02, 100-watt 6.83 +/-0.06 mg/L of 02, 150-watt 7.00 +/-0.00 mg/L 02), the mutants also showed a statistically significant difference between the treatments (0-watt 5.60 +/-0.00mg/L of 02, 60-watt 6.43 +/-0.06 mg/L of 02, 100-watt 6.9 +/-0.1 mg/L of 02, 150-watt 6.87 +/-0.15 mg/L of 02). However, when the results from both the wild type and mutant trials were compared there was no significant difference in the data. From this data we were able to conclude that the rate of photosynthesis increased as light intensity increased.