Northern Facing Slope Lab Report
Evolution Canyon is a canyon in Israel where the two slopes face very different conditions. The Northern Facing Slope (NFS) is lush, green, and shaded while the Southern Facing Slope (SFS) is dry and has little protection from intense sunlight. Evolution Canyon is a natural laboratory, meaning that nature has provided variations, allowing it to be a great location for experiments. Specifically, it is a great location to study natural selection and evolution. Researches from the Imperial College of Science, Technology and Medicine in London, England conducted research in the canyon using Sordaria. Since many other organisms in the canyon have evolved as a result of their environment, they sought out differences in the cross over …show more content…
After observing, the perithecia had to be broken in order to release the asci and observe the spores. This was done by tapping on the surface of the slide cover with a pencil eraser. Then each student placed the slide back under the microscope for observation and calculation.
Each student counted a total of 20 asci and classified them as Type A (4:4), Type B (2:4:2), or Type C (2:2:2:2). After each student completed their own counting, the class combined results.
In order to find the cross-over frequency the following formula was used:
Cross Over= (B+C)/(A+B+C)
Therefore, the cross-over frequency is found by adding the total number of recombinant asci and dividing that by the total number of asci. In order to calculate map distance, which is the distance the chromosome is from the centromere, the following formula was used:
Map Distance= (% Crossed Over)/2
The percentage of cross-over must be divided by two because mitosis occurred, duplicating the cells. Therefore, only half of the spores are from crossing-over.
Table 1: This table shows the numbers of asci scored for each ascus type as well as the total.
Non-recombinant Recombinant Total # of Asci Total # Recombinant Asci