BIOSC-116 Lecture Notes - Lecture 9: Sister Chromatids, Nuclear Membrane, Meiosis
16 Jun 2020
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Document Summary
Essentially the process of mitosis, except it"ll look a little different because the cells have previously gone thought meiosis i. Chromosomes align in single file on the midline of the cell, just like in mitosis. One sister chromatid on either side of the line. Evidence of crossing over that occurred during prophase i. There are only 23 chromosomes not 46. Spindle fibers pulls sister chromatids apart at their centromeres. Sister chromatids go to opposite poles of the cell. End up with single chromosomes again by the end of anaphase ii. New nuclear envelopes forming around each group of chromosomes. Yields 4 haploid daughter cells that are genetically unique: anaphase ii, telophase ii, cytokinesis. Meiosis and sexual reproduction increase genetic variation between individuals. Three events contribute to genetic variation: crossing over, independent assortment of chromosomes, recombination of genes between 2 individuals during fertilization. The genes we inherit from our parents dictate the traits we exhibit.
