Introduction to Sordaria Lab Report

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The lab experiment examined meiosis and genetic diversity through the model organism, Sordaria fimicola. Meiosis is part of the sexual life cycle and occurs in all sexually reproducing organisms. It is a method of cell division that produces gametes. Meiosis has two parts: meiosis I and meiosis II. Both parts undergo the same four stages of prophase, metaphase, anaphase, and telaphase. The process begins with one single parent diploid cell (that contain homologous chromosomes) that divides into four daughter haploid cells which each contain half the number of chromosomes that the original parent cell contained. Both independent assortment and crossing over occur in meiosis I. Crossing over rearranges the DNA sequences that are then inherited and passed down to future offspring. This rearrangement, or recombination results in genetic variation within a species. The mechanisms controlling these crossover events are undefined. Recent existing evidence argues that harsh environmental pressures may lead to heritable changes in mechanisms controlling recombination. Much of this evidence has come from studies done at the Evolution Canyons in Israel. There are four “Evolution Canyons”, each of which consists of two mountain slopes with varying climates. Evolution Canyon I, located in Lower Nahal Oren, Mount Carmel, contains a south facing slope (SFS) which experiences harsh climatic conditions, such as high temperatures and drought. The opposing north facing slope (NFS) is characterized by mild climatic conditions, including cooler temperatures and higher humidity. Evolution Canyon serves as a model for microevolution and can be used to study how mutation and recombination contribute to adaptation and genetic diversity. The study published in the Genetics Journal and referred to in the biology laboratory manual studied whether there is a natural genetic variation for recombination frequencies and whether it correlates to environmental conditions and adaptation. The...
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