The effect of temperature on DNA concentration and cell size of


  • Adit Dhariwal
  • Chandan Dhillon
  • Ryan To


Chlamydomonas reinhardtii is a primary producer in many freshwater ecosystems. With
temperatures increasing due to global warming, the effect on their cellular processes is of
concern since they form the basis of the salmon food web. The purpose of studying C.
reinhardtii was to investigate the effects of temperature on DNA concentration and cell size. It
was predicted that temperature would affect both DNA concentration and cell size of C.
reinhardtii. Our methods consisted of two different temperature treatments, 30°C, and 39°C,
consisting of 3 replicates each, over 48 hours. To conduct our research, we intermittently
extracted the cultures to measure cell growth, perform cell counts and isolate the DNA. This was
done using both a hemocytometer and compound microscope in addition to multiple fixatives.
The results generated from a two-way ANOVA produced p-values of <0.0001, 0.0556, and
0.0037 for DNA concentration corresponding to time, temperature, and interaction respectively.
Consequently, we were able to determine that temperature had no significant effect on DNA
concentration (p>0.05). Conversely, the p-value for time and interaction was less than 0.05
(p<0.05) inferring that there was a significance. Additionally, for cell size, the p-values obtained
were 0.0137, 0.0330, and 0.4050 for time, temperature, and interaction respectively. Thus, no
significance was found for interaction (p>0.05), however, for time and temperature, there was an
observed significance (p<0.05). However, despite ANOVA results for cell size, Sidak’s test was
unable to identify where the significance resulted from. In conclusion, the temperature was
found to affect C. reinhardtii cell size, but DNA concentration was relatively unaffected in
comparison with the two temperature treatments.