| Explore | We chose this experiment because c-ferns are homosporous ferns meaning they produce one kind of spore that can either grow into a male or a hermaphrodite. To prevent having competitions the first hermaphrodite to develop releases antheridiogen preventing the spores from turning into hermaphrodites forcing them to become males. Knowing this we diluted the water to get the different amounts of spores in each petri dish. |
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| Research Question | How can we impact the haploid generation of Cferns? Does seperating the spores by diluting solutions containing the spores restrict the transfer of antheridiogen and affect the proportion of females to males? |
| Predictions | If the spores are separated then the proportion of hermaphrodites to males increases because the hormone, antheridiogen, wouldn't affect the same number of developing spores, so more hermaphrodites will develop. |
| Experimental Design | To set up the experiment, only certain resources were available. The resources available were these: 4 petri dishes, C-fern spores, diluted water, pipet, and graduated cylinders. In the experiment, the concentration of spores was the independent variable that was changed by different levels of dilution. By putting 300, 200, and 100 spores in 4mL of water and taking 3 drops from a single graduated cylinder, using a pipet, into a petri dish, different concentrations of spores were obtained. With these different levels of concentration, there were different numbers of spores per petri dish. Therefore, the equation: 3 drops x 1 ml/20drops x 300spores/4ml = 11.25. Then, this equation was evaluated for 200 and 100 spores for the results of approximately 11.25, 7.5, and 3.75 spores per petri dish. |
| Conclusion | Claim: After looking at our data it has been determined the petri dishes with the lower concentration had a higher proportion of hermaphrodites to males, and the petri dishes with higher concentration had a lower proportion of hermaphrodites to males. Evidence:Under the microscope we find that a low concentration of spores corresponds with a higher proportion of hermaphrodites to males in the petri dishes. However, with a high concentration of spores we find a higher proportion of males to hermaphrodites. Also, we find that in the petri dishes with a proportion of more hermaphrodites there was a low concentration of spores that were dropped into the petri dishes. However, when we see more males in the petri dishes there was a higher concentration of spores dropped into the petri dishes. Also, the proportions of hermaphrodites in 3.75 was about 3:4, in 7.5 it was about 1:8, in 11.25 it was about 1:2, and in 300, it was about 1:15. This shows that the proportion increased in association with distance between spores. Reasoning: Having a high and a low concentration affected the spores because the antheridiogen has a certain range, and beyond this range, other spores will not be affected. This prevented the antheridiogen from prohibiting the development of other spores. |
| Investigation Theme | CFERN |
| Grade Level | High School Students (Grades 9,10,11,12) |
| School Name | Central High School |
| Session | Spring 2018 |