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Sordaria Fimicola Lab Report

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Nicole Hain
Bio 110
Sordaria fimicola Lab Report
Introduction
“Evolution Canyon” consists of two slopes in Israel that are close in proximity, but have a huge difference in environment. This makes the slopes a good model system for exploring evolution, especially because they’re so close to one another. The South Facing Side (SFS) receives more sunlight than the North Facing Side (NFS). This extreme sun exposure causes the South slope to have drought and arid conditions whereas the North side has more temperate conditions and is shady and humid. The model, Sordaria fimicola, reproduces through the process of Meiosis and their chromosomes cross over in Prophase I (Stern). S. fimicola have different crossover frequencies between the slopes
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The squashes were prepared by using an inoculating loop to scrape perithecia from the center of one of the dividing lines. A sample from the dividing lines was placed on a microscope slide and a drop of water was added followed by a coverslip. A pencil eraser was used to release the asci from the perithecia by pushing down on the coverslip. Under the microscope, the asci were observed and recorded to find recombination patterns.
The total number of recombinants of Type B asci and Type C asci was divided by the total amount of the recombinants and non-recombinants counted. The percentage was calculated by multiplying the previous answer by 100. The map distance was found by dividing the percent of the crossovers by 2 because each crossover produced two spores identical to the parents and two spores that resulted from the crossover.

Results
Table 1. Ascus Scored

Non-recombinant # of Type A Asci
(4:4)
Recombinant
Total # of Asci
Total # Recombinant Asci

# of Type B
(2:4:2)
# of Type C
(2:2:2:2)

Class Data
159
125
136
420
261
Section Data
6,358
5,105
4,908
16,371
10,013

Table 2. Crossover Frequencies

Frequency of Recombinant Asci
Frequency of Type B Asci
Frequency of Type C Asci
Ratio B/C
Class Data
62.1%
29.7%
32.4%
.92
Section Data
61.2%
31.2%
30%
1.04

(eg Figure 1)
Figure 1 is one of the many asci groups found of recombinants and non-recombinants under a microscope of 400x. The eight asci circled in red represents a 2:2:2:2 pattern of crossover between the spore
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