BIOLOGY 2C03 Lecture Notes - Lecture 4: Aneuploidy, Advanced Maternal Age, Karyotype
4 May 2017
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Document Summary
Crossing over occurs for an exchange of genetic material (dna) between non sister chromatids - synapsis. When paired, homologous pairs are referred to as tetrads or bivalents. Spindles form, connects to the centromeres of each tetrad consisting of four sister chromatids. Left side microtubules attach to the red, right attach to the blue. However, the red and blue (two chromosomes in the tetrad) are attached to each other. This is metaphase 1 where independent assortment occurs. The one chromosome centromere is separated from the other. On each side, we have a full chromosome set. Create a two haploid set - one with a short chromosome, one with a long chromosome. Centromeres have to stay attached all through meiosis 1, until you get to. Centromeres have to stay attached all through meiosis 1, until you get to anaphase two that the separation of centromeres can occur. Telophase - four haploid cell each containing one short and one long chromosome.
