{"id":207,"date":"2012-11-05T15:35:15","date_gmt":"2012-11-05T19:35:15","guid":{"rendered":"https:\/\/sites.owu.edu\/wolverton\/?page_id=207"},"modified":"2016-12-01T08:50:41","modified_gmt":"2016-12-01T13:50:41","slug":"cell-division","status":"publish","type":"page","link":"https:\/\/sites.owu.edu\/wolverton\/teaching\/cell-bio\/cell-division\/","title":{"rendered":"Cell Division"},"content":{"rendered":"<h2>Links<\/h2>\n<p><a href=\"http:\/\/www.nature.com\/principles\/ebooks\/introduction-to-cell-biology-4570805\/4569856\">Principles Module 32<\/a><\/p>\n<h2>Objectives<\/h2>\n<ul>\n<li>Detail the differences between division in prokaryotic and eukaryotic cells<\/li>\n<li>Define the cellular structures involved in mitosis and cytokinesis<\/li>\n<li>Describe the eukaryotic cell cycle and phases of mitosis<\/li>\n<\/ul>\n<h2>Key Points<\/h2>\n<h3>Bacterial cell division<\/h3>\n<ul>\n<li>division is different in prokaryotes and eukaryotes by necessity<\/li>\n<li>binary fission is simple division in bacteria<\/li>\n<ul>\n<li>single circular chromosome replicated at same time as division<\/li>\n<li>proteins control partitioning of DNA into daughter cells<\/li>\n<li>replication begins at ori site, goes bidirectionally around<\/li>\n<li>septum separates the 2 new cells<\/li>\n<ul>\n<li>formation is regulated by proteins<\/li>\n<li>forms at midpoint of cell, FtsZ protein forms ring<\/li>\n<\/ul>\n<\/ul>\n<\/ul>\n<h3>Eukaryotic chromosomes<\/h3>\n<ul>\n<li>packaging\n<ul>\n<li>40% DNA, 60% protein called histones<\/li>\n<li>allow for coiling of DNA, packaging to hi density<\/li>\n<li>~ 200 bp = 8 histones = nucleosome<\/li>\n<li>nucleosomes wrapped into solenoids, form 30 nm fiber<\/li>\n<\/ul>\n<\/li>\n<li>ploidy\n<ul>\n<li>haploid is the number of chromosomes a species has\n<ul>\n<li>human haploid # is 23<\/li>\n<li>Arabidopsis haploid # is 5<\/li>\n<\/ul>\n<\/li>\n<li>many species have 2 <em>versions<\/em>of each chromosome, are diploid\n<ul>\n<li>versions called homologues, encode same genes at same places<\/li>\n<li>slight differences in each from parents (alleles)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<li>replication<\/li>\n<ul>\n<li>results in each chromosome having exact duplicate copy<\/li>\n<li>copies held together as sister chromatids<\/li>\n<\/ul>\n<\/ul>\n<h3>Overview of eukaryotic cell cycle<\/h3>\n<ul>\n<li>interphase\n<ul>\n<li>G1 (gap) growth phase, majority of most cells\u2019 cycle<\/li>\n<li>S synthesis of exact copy of genome<\/li>\n<li>G2 (gap 2) growth, organelle replication, prep for mitosis<\/li>\n<\/ul>\n<\/li>\n<li>M (mitosis) separation of 2 daughter genomes<\/li>\n<li>cytokinesis partitioning of cytoplasm<\/li>\n<\/ul>\n<h3>Structures<\/h3>\n<ul>\n<li>centromere is a constriction on chromosome\n<ul>\n<li>made up of repeat sequences of DNA<\/li>\n<\/ul>\n<\/li>\n<li>kinetochore a disk shaped collection of proteins attached to centromere\n<ul>\n<li>microtubules attach here during mitosis<\/li>\n<\/ul>\n<\/li>\n<li>centrioles\n<ul>\n<li>MT organizing centers at poles of cell<\/li>\n<\/ul>\n<\/li>\n<li>spindle is MT network that pulls chromosomes apart<\/li>\n<\/ul>\n<h3>Mitosis<\/h3>\n<ul>\n<li>prophase\n<ul>\n<li>condensation of chromosomes<\/li>\n<li>spindle apparatus forms<\/li>\n<li>nuclear envelope disintegrates<\/li>\n<\/ul>\n<\/li>\n<li>prometaphase\n<ul>\n<li>chromosomes attach to spindle at kinetochore<\/li>\n<li>congression pulls chromosomes to center of cell\n<ul>\n<li>recall the growth of MTs by adding and subtracting tubulins<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<li>metaphase\n<ul>\n<li>chromosomes aligned at cell equator, called the metaphase plate<\/li>\n<\/ul>\n<\/li>\n<li>anaphase\n<ul>\n<li>centromeres split, sister chromatids separate from each other<\/li>\n<li>kinetochores pulled toward poles by removal of tubulins<\/li>\n<li>poles move apart<\/li>\n<\/ul>\n<\/li>\n<li>telophase<\/li>\n<ul>\n<li>spindle breaks down, nuclear envelope reconstitutes<\/li>\n<li>chromosomes de-condense<\/li>\n<\/ul>\n<\/ul>\n<h3>Cytokinesis<\/h3>\n<ul>\n<li>cells w\/out walls\n<ul>\n<li>actin forms a belt, constricts to pinch cell, form cleavage furrow<\/li>\n<\/ul>\n<\/li>\n<li>cells w\/ walls\n<ul>\n<li>deposits of membrane, new wall carbohydrates in middle, cell plate<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2>In-class Activities<\/h2>\n<h2>Questions for Practice<\/h2>\n<ul>\n<li>Compare and contrast prokaryotic and eukaryotic division. What are some reasons <em>why<\/em>\u00a0this process should be different?<\/li>\n<li>What is the mitotic spindle? What is it made of? When does it form?<\/li>\n<li>List and briefly describe each of the major phases of mitosis.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Links Principles Module 32 Objectives Detail the differences between division in prokaryotic and eukaryotic cells Define the cellular structures involved in mitosis and cytokinesis Describe the eukaryotic cell cycle and phases of mitosis Key Points Bacterial cell division division is different in prokaryotes and eukaryotes by necessity binary fission is simple division in bacteria single [&hellip;]<\/p>\n","protected":false},"author":40,"featured_media":0,"parent":447,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-207","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/pages\/207","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/users\/40"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/comments?post=207"}],"version-history":[{"count":1,"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/pages\/207\/revisions"}],"predecessor-version":[{"id":493,"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/pages\/207\/revisions\/493"}],"up":[{"embeddable":true,"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/pages\/447"}],"wp:attachment":[{"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/media?parent=207"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}