30 October 2012
Meiosis and genetic diversity in the model organism, Sordaria
Meiosis is a process in which a cell divides to form four haploid (1N) cells. The Sordaria lab is a perfect way to see an example of how meiosis impacts the life of an organism. Meiosis can be broken down into parts that contain a few stages. These stages are similar to that in Mitosis (Prophase, Metaphase, Anaphase, and telaphase.) during Meiosis I, crossing over and independent assortment occur for genetic variation. Genetic Variation is a very important thing for a species because it helps organisms adapt. Meiosis I is similar to Mitosis because it forms two daughter cells, but crossing over that occurs during Prophase I. The end result of Meiosis II is there will be four haploid daughter cells that are genetically different. When two haploid cells form a zygote they develop into a mature organism.
The way my group examined meiosis was through a lab that compared spores that reproduced between a wild type and tan. The wild type Sordaria produced black spores. Me and my group members placed two pieces of the wild type Sordaria and two pieces of the tan sordaria and let them reproduce more for two weeks. After the sample incubated we observed the genotype of the asci by breaking the perithecia. The reason we did this was to find the distance between the gene and the centromere. This was done to show how much sexual reproduction between organisms increases genetic variation between them. This method was a great way of getting a good amount of data. Results:
After the two week incubation period groups went and looked at their mating plate and found out what types of asci were produced and how many of them. This data was important for each group because it all added up to the whole courses total data Table 1. Individual Data: (record your assigned spore color) Non-recombinant| Recombinant| Total # of...