{"id":4972,"date":"2019-11-03T09:53:10","date_gmt":"2019-11-03T17:53:10","guid":{"rendered":"https:\/\/integrativewellnessandmovement.com\/iwmbasicscience\/?p=4972"},"modified":"2019-11-03T10:29:58","modified_gmt":"2019-11-03T18:29:58","slug":"embryology-meiosis","status":"publish","type":"post","link":"https:\/\/integrativewellnessandmovement.com\/iwmbasicscience\/embryology\/embryology-meiosis\/","title":{"rendered":"Embryology: Meiosis"},"content":{"rendered":"\n<p class=\"has-medium-font-size\">Interphase.<\/p>\n\n\n\n<p class=\"has-medium-font-size\">Meiosis I.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Generates the most diversity.<\/li><li>Starts diploid.<\/li><li><strong>Prophase 1.<\/strong> DNA has already been replicated prior to Meiosis I. Homologous chromosomes pair (<strong>bivalents<\/strong>) to form synapses. Chromosomes condense.<\/li><li><strong>Bivalent<\/strong>. Has 2 chromosomes and 4 chromatids. A pair of homologous chromosomes.<\/li><li><strong>Homologous chromosomes<\/strong>. One maternal chromosome and one paternal chromosome.<\/li><li><strong>Synapses<\/strong>. <strong>Crossover <\/strong>&#8220;mutations&#8221; can occur when homologous chromosomes pair up.<\/li><li><strong>Synaptonemal complex<\/strong>. Protein that holds homologuess together.<\/li><li><strong>Prometaphase 1<\/strong>. Nuclear membrane disappears. One kinetochore per one chromosome (instead of per chromatid). Chromosomes attach to spindle fibers.<\/li><li><strong>Metaphase 1<\/strong>. Bivalents (2 chromosomes, 4 chromatids) align at metaphasic plate.<\/li><li><strong>Anaphase 1<\/strong>. <strong>Chiasmata <\/strong>separate. Chromosomes (each with 2 chromatids) move to opposite poles. Each daughter is now haploid (n).<\/li><li><strong>Telephase 1<\/strong>. Nuclear envelope may reform or it may just go into Meiosis 2.<\/li><li><strong>Chiasmata<\/strong>. The point where paired chromosomes remain in contact together during meiosis 1. X-shape area. Help keep homologues together after synaptonemal complex breaks down.<\/li><li>Ends haploid.<\/li><\/ul>\n\n\n\n<p class=\"has-medium-font-size\">Meiosis 2.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>There is no copying of DNA when going from Meiosis I to Meiosis II.<\/li><li>&#8220;Meiosis for haploid cells&#8221;.<\/li><li>Starts haploid.<\/li><li>Meiosis 2 is shorter and simpler.<\/li><li>Cells entering are haploid. They have one chromosome from each homologous pair. Each chromosome still has 2 sister chromatids.<\/li><li><strong>Prophase 2<\/strong>. Nuclear envelope (if it had reformed prior) breaks. Chromosome condense.<\/li><li><strong>Prometaphase 2<\/strong>. Spindle is fully formed. Each sister chromatid forms an individual kinetochore that attaches to spindle.<\/li><li><strong>Metaphase 2.<\/strong> Sister chromatids line up at metaphasic plate.<\/li><li><strong>Anaphase 2<\/strong>. Sister chromatids split up and move to opposite poles. Pulled apart by kinetochore microtubules.<\/li><li><strong>Telophase 2<\/strong>. Chromosomes decondense. Nuclear envelope reforms. Cytokinesis. Results with 4 haploid cells.<\/li><li>Ends haploid.<\/li><\/ul>\n\n\n\n<p class=\"has-medium-font-size\">Resources.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>  <a rel=\"noreferrer noopener\" aria-label=\" (opens in a new tab)\" href=\"https:\/\/www.khanacademy.org\/science\/biology\/cellular-molecular-biology\/meiosis\/a\/phases-of-meiosis\" target=\"_blank\">https:\/\/www.khanacademy.org\/science\/biology\/cellular-molecular-biology\/meiosis\/a\/phases-of-meiosis<\/a> <\/li><li> <a href=\"https:\/\/courses.lumenlearning.com\/wm-biology1\/chapter\/reading-meiosis-i\/\" target=\"_blank\" rel=\"noreferrer noopener\" aria-label=\" (opens in a new tab)\">https:\/\/courses.lumenlearning.com\/wm-biology1\/chapter\/reading-meiosis-i\/<\/a> <\/li><li> <a rel=\"noreferrer noopener\" aria-label=\" (opens in a new tab)\" href=\"https:\/\/courses.lumenlearning.com\/wm-biology1\/chapter\/reading-meiosis-ii\/\" target=\"_blank\">https:\/\/courses.lumenlearning.com\/wm-biology1\/chapter\/reading-meiosis-ii\/<\/a> <\/li><\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Interphase. Meiosis I. Generates the most diversity. Starts diploid. Prophase 1. DNA has already been replicated prior to Meiosis I. Homologous chromosomes pair (bivalents) to form synapses. Chromosomes condense. Bivalent. Has 2 chromosomes and 4 chromatids. A pair of homologous chromosomes. Homologous chromosomes. One maternal chromosome and one paternal chromosome. Synapses. Crossover &#8220;mutations&#8221; can occur [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[51],"tags":[],"class_list":["post-4972","post","type-post","status-publish","format-standard","hentry","category-embryology"],"_links":{"self":[{"href":"https:\/\/integrativewellnessandmovement.com\/iwmbasicscience\/wp-json\/wp\/v2\/posts\/4972","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/integrativewellnessandmovement.com\/iwmbasicscience\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/integrativewellnessandmovement.com\/iwmbasicscience\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/integrativewellnessandmovement.com\/iwmbasicscience\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/integrativewellnessandmovement.com\/iwmbasicscience\/wp-json\/wp\/v2\/comments?post=4972"}],"version-history":[{"count":4,"href":"https:\/\/integrativewellnessandmovement.com\/iwmbasicscience\/wp-json\/wp\/v2\/posts\/4972\/revisions"}],"predecessor-version":[{"id":4976,"href":"https:\/\/integrativewellnessandmovement.com\/iwmbasicscience\/wp-json\/wp\/v2\/posts\/4972\/revisions\/4976"}],"wp:attachment":[{"href":"https:\/\/integrativewellnessandmovement.com\/iwmbasicscience\/wp-json\/wp\/v2\/media?parent=4972"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/integrativewellnessandmovement.com\/iwmbasicscience\/wp-json\/wp\/v2\/categories?post=4972"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/integrativewellnessandmovement.com\/iwmbasicscience\/wp-json\/wp\/v2\/tags?post=4972"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}