Dr. Ross's Embryology Course Meiosis Stages Lecture Unit 1 Lab Unit 1

It will take a moment for the images to load. Dr. Newman has given me permission to copy his images here. Dr. Newman's Meiosis Stages illustrations are back online!  Here's a link: Meiosis Stages Here's the new URL--  http://www.irn.pdx.edu/~newmanl/StageDescriptions.html

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	Meiosis. 1. Meiosis I -- separates the homologous chromosomes. 1.a. Prophase I. Bivalent (divalent): The structure formed by a pair of homologouschromosomes joined by synapsis along their length during the zygotene and pachytene stages of the first meioticprophase. After each of the paired chromosomes separates into two sister chromatids during the pachytene stage, this structure is then called a tetrad. Dictyotene: The protracted stage, a suspended first meiotic prophase, in which the primary oocyte persists from late fetal life until near the time of ovulation at or after puberty. 1.a.1. Leptotene.  1.a.2. Zygotene.  1.a.3. Pachytene.  1.a.4. Diplotene.  1.a.5. Diakinesis.  1.b. Metaphase I 1.c. Anaphase I 1.d. Telophase I.  2. Meiosis II -- separates sister chromatids. 2.a. Prophase II. This phase is short (unlike Prophase I) 2.b. Metaphase II 2.c. Anaphase II 2.d. Telophase II.
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More Resources about Meiosis: Meiosis tutorial (includes stages of prophase)  Grasshopper Spermatogenesis (Univ. Guelph) Cell Cycle Tutorial (scroll down for details about meiosis) Meiosis and Fertilization in Ascaris (Univ. Guelph) Introductory level Meiosis Tutorial (Arizona)  Meiosis Stages (Dr. Newman's Meiosis Stages)

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Comments & Questions: Please contact Dr. Anna E. Ross email: aross@cbu.edu