Sordaria Lab Report
Meiossis and Genetic Diversity in Sordaria
Meiosis and Genetic Diversity in the Model Organism, Sordaria.
By: Katie Fiorillo
BIO110 Lab
TA: Lauren Smith
October 30, 2012
A. INTRODUCTION: In this lab, the organism Sordaria fimicola was used to explore factors contributing to genetic evolution of sexual reproduction. These organisms are found in “Evolution Canyons,” which occur when two mountain slopes with very different climatic conditions congregate with a comparatively small valley between them. The organisms found on the south facing slope (SFS) slope of evolution canyon, which has harsher environmental conditions, have an increased mutation rate. This increased mutation rate may lead to inherited changes in mechanisms …show more content…
Using a compound microscope, locate the asci using the 100x magnification. Once located, observe under 400x magnification. Look for ascus sacs that contain more than one spore color. These were formed by the fusion of the two strains. 6. Draw a sample perithecium that displays numerous asci suitable for scoring the asci.
EXPERIMENT PART C: SCORING ASCI
1. Use the individual data table to score at least 20 asci in the appropriate columns. 2. Combine this data into the small group data table. 3. Compile class data.
RESULTS
Table 1: Individual Data Non-recombinant | Recombinant | Total # of asci | Total # of recombinant asci (B+C) | # of Type A Asci (4:4) | # of Type B Asci (2:4:2) | # of Type C Asci (2:2:2:2) | | | 9 | 5 | 6 | 20 | 11 |
Non-recombinant | Recombinant | Total # of Asci | Total # of Recombinant Asci | # of Type A Asci | # of Type B Asci | # of Type C Asci | | | 25 | 14 | 21 | 60 | 36 |
Table 2: Combined Lab Group Data (Wild and Tan)
Table 3: Combined Section Data Non-recombinant | Recombinant | Total # of asci | Tota; # of rebcombinant (B+C) | # Type A (4:4) | # Type B (2:4:2) | #Type C (2:2:2:2) | | | Tan Spore Color | 104 | 66 | 73 | 243 | 139 | Gray Spore Color | 81 | 31 | 49 | 161 | 80 …show more content…
See table 6.
-What is the map distance for each spore color gene form the centromere? It is equal to the frequency of recombination multiplied by 100 and then divided by 2. For example, the map distance for Type B of the tan spore color is 15.42.
-Is there any variation in the ratio of the two crossover types between gray and tan spore color genes? There was not a significant difference in the ratios of the crossover types between the gray and tan spore color genes.
Research Question: How does exposure to environmental stresses applied under controlled conditions change the crossover frequency in populations of Sordaria fimicola? It is obvious form this lab that environmental conditions play a huge role in genetic variation. In a lab where the environment was controlled, there was little differences in the variations between the two spore colors. This is not the case in the wild, where there was great variation in the ratios. This proves that the environmental stresses add to
Meiosis and Genetic Diversity in the Model Organism, Sordaria.
By: Katie Fiorillo
BIO110 Lab
TA: Lauren Smith
October 30, 2012
A. INTRODUCTION: In this lab, the organism Sordaria fimicola was used to explore factors contributing to genetic evolution of sexual reproduction. These organisms are found in “Evolution Canyons,” which occur when two mountain slopes with very different climatic conditions congregate with a comparatively small valley between them. The organisms found on the south facing slope (SFS) slope of evolution canyon, which has harsher environmental conditions, have an increased mutation rate. This increased mutation rate may lead to inherited changes in mechanisms …show more content…
Using a compound microscope, locate the asci using the 100x magnification. Once located, observe under 400x magnification. Look for ascus sacs that contain more than one spore color. These were formed by the fusion of the two strains. 6. Draw a sample perithecium that displays numerous asci suitable for scoring the asci.
EXPERIMENT PART C: SCORING ASCI
1. Use the individual data table to score at least 20 asci in the appropriate columns. 2. Combine this data into the small group data table. 3. Compile class data.
RESULTS
Table 1: Individual Data Non-recombinant | Recombinant | Total # of asci | Total # of recombinant asci (B+C) | # of Type A Asci (4:4) | # of Type B Asci (2:4:2) | # of Type C Asci (2:2:2:2) | | | 9 | 5 | 6 | 20 | 11 |
Non-recombinant | Recombinant | Total # of Asci | Total # of Recombinant Asci | # of Type A Asci | # of Type B Asci | # of Type C Asci | | | 25 | 14 | 21 | 60 | 36 |
Table 2: Combined Lab Group Data (Wild and Tan)
Table 3: Combined Section Data Non-recombinant | Recombinant | Total # of asci | Tota; # of rebcombinant (B+C) | # Type A (4:4) | # Type B (2:4:2) | #Type C (2:2:2:2) | | | Tan Spore Color | 104 | 66 | 73 | 243 | 139 | Gray Spore Color | 81 | 31 | 49 | 161 | 80 …show more content…
See table 6.
-What is the map distance for each spore color gene form the centromere? It is equal to the frequency of recombination multiplied by 100 and then divided by 2. For example, the map distance for Type B of the tan spore color is 15.42.
-Is there any variation in the ratio of the two crossover types between gray and tan spore color genes? There was not a significant difference in the ratios of the crossover types between the gray and tan spore color genes.
Research Question: How does exposure to environmental stresses applied under controlled conditions change the crossover frequency in populations of Sordaria fimicola? It is obvious form this lab that environmental conditions play a huge role in genetic variation. In a lab where the environment was controlled, there was little differences in the variations between the two spore colors. This is not the case in the wild, where there was great variation in the ratios. This proves that the environmental stresses add to