The resulting sub-culture population will be allowed to develop for a few days, then it will be separated into two equal portions. These two equal portions will be cultured under conditions that are identical, except for one factor, thus creating a control culture and an experimental culture. These two populations, now separate, will be allowed to develop for a few more days. Finally, the two cultures will be compared to see which has the higher cell density. The result of this comparison will be the basis for your conclusion about the effect of the experimental factor.
Preparation Make a hay infusion to provide a population of wild protists.
Spend some time viewing protists from the wild culture as it develops. Note changes in the types and numbers of protists present as the population develops. Make a formal drawing of one of the protists. Decide on a general topic for your experiment. Choose a topic worth the time it will take to investigate.