{"id":2388,"date":"2016-05-24T20:37:58","date_gmt":"2016-05-24T20:37:58","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/biologyxwaymakerxmaster\/?post_type=chapter&#038;p=2388"},"modified":"2024-04-26T22:29:16","modified_gmt":"2024-04-26T22:29:16","slug":"reading-mitosis","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/wm-biology1\/chapter\/reading-mitosis\/","title":{"raw":"Mitosis","rendered":"Mitosis"},"content":{"raw":"<div class=\"textbox learning-objectives\">\r\n<h3>Learning Outcomes<\/h3>\r\n<ul>\r\n \t<li>Identify the characteristics and stages of mitosis<\/li>\r\n<\/ul>\r\n<\/div>\r\nThe mitotic phase (also known as M phase) is a multistep process during which the duplicated chromosomes are aligned, separated, and move into two new, identical daughter cells. The first portion of the mitotic phase is called\u00a0<strong>karyokinesis<\/strong>, or nuclear division. The second portion of the mitotic phase, called cytokinesis, is the physical separation of the cytoplasmic components into the two daughter cells.\r\n<h2>Karyokinesis (Mitosis)<\/h2>\r\nKaryokinesis, also known as mitosis, is divided into a series of phases\u2014prophase, prometaphase, metaphase, anaphase, and telophase\u2014that result in the division of the cell (Figure\u00a01).\r\n<figure data-id=\"fig-ch10_02_02real\">\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"898\"]<img id=\"30715\" class=\"\" title=\"credit \u201cmitosis drawings\u201d: modification of work by Mariana Ruiz Villareal; credit \u201cmicrographs\u201d: modification of work by Roy van Heesbeen; credit \u201ccytokinesis micrograph\u201d: Wadsworth Center\/New York State Department of Health; scale-bar data from Matt Russell\" src=\"https:\/\/openstax.org\/resources\/a4eaf13f166b21e46b42467ac67eb6a949a76560\" alt=\"This diagram shows the five phases of mitosis and cytokinesis. During prophase, the chromosomes condense and become visible, spindle fibers emerge from the centrosomes, the nuclear envelope breaks down, and the nucleolus disappears. During prometaphase, the chromosomes continue to condense and kinetochores appear at the centromeres. Mitotic spindle microtubules attach to the kinetochores, and centrosomes move toward opposite poles. During metaphase, the mitotic spindle is fully developed, and centrosomes are at opposite poles of the cell. Chromosomes line up at the metaphase plate and each sister chromatid is attached to a spindle fiber originating from the opposite pole. During anaphase, the cohesin proteins that were binding the sister chromatids together break down. The sister chromatids, which are now called chromosomes, move toward opposite poles of the cell. Non-kinetochore spindle fibers lengthen, elongating the cell. During telophase, chromosomes arrive at the opposite poles and begin to decondense. The nuclear envelope reforms. During cytokinesis in animals, a cleavage furrow separates the two daughter cells. In plants, a cell plate separates the two cells.\" width=\"898\" height=\"743\" data-media-type=\"image\/png\" \/> Figure\u00a01. <strong>Stages of mitosis<\/strong>. Karyokinesis (or mitosis) is divided into five stages\u2014prophase, prometaphase, metaphase, anaphase, and telophase. The pictures at the bottom were taken by fluorescence microscopy (hence, the black background) of cells artificially stained by fluorescent dyes: blue fluorescence indicates DNA (chromosomes) and green fluorescence indicates microtubules (spindle apparatus).[\/caption]<\/figure>\r\nDuring\u00a0<strong>prophase<\/strong>, the \u201cfirst phase,\u201d the nuclear envelope starts to dissociate into small vesicles, and the membranous organelles (such as the Golgi complex or Golgi apparatus, and endoplasmic reticulum) fragment and disperse toward the periphery of the cell. The nucleolus disappears (disperses). The centrosomes begin to move to opposite poles of the cell. Microtubules that will form the mitotic spindle extend between the centrosomes, pushing them farther apart as the microtubule fibers lengthen. The sister chromatids begin to coil more tightly with the aid of <strong>condensin<\/strong> proteins and become visible under a light microscope.\r\n\r\n[caption id=\"attachment_1801\" align=\"alignright\" width=\"400\"]<img class=\"wp-image-1801\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/110\/2016\/05\/03205004\/Figure_10_02_03.jpg\" alt=\"This illustration shows two sister chromatids. Each has a kinetochore at the centromere, and mitotic spindle microtubules radiate from the kinetochore.\" width=\"400\" height=\"293\" \/> Figure\u00a02. During prometaphase, mitotic spindle microtubules from opposite poles attach to each sister chromatid at the kinetochore. In anaphase, the connection between the sister chromatids breaks down, and the microtubules pull the chromosomes toward opposite poles.[\/caption]\r\n\r\nDuring <strong>prometaphase<\/strong>, the \u201cfirst change phase,\u201d many processes that were begun in prophase continue to advance. The remnants of the nuclear envelope fragment. The mitotic spindle continues to develop as more microtubules assemble and stretch across the length of the former nuclear area. Chromosomes become more condensed and discrete. Each sister chromatid develops a protein structure called a kinetochore in the centromeric region (Figure\u00a02). The proteins of the kinetochore attract and bind mitotic spindle microtubules. As the spindle microtubules extend from the centrosomes, some of these microtubules come into contact with and firmly bind to the kinetochores. Once a mitotic fiber attaches to a chromosome, the chromosome will be oriented until the kinetochores of sister chromatids face the opposite poles. Eventually, all the sister chromatids will be attached via their kinetochores to microtubules from opposing poles. Spindle microtubules that do not engage the chromosomes are called polar microtubules. These microtubules overlap each other midway between the two poles and contribute to cell elongation. Astral microtubules are located near the poles, aid in spindle orientation, and are required for the regulation of mitosis.\r\n\r\nDuring\u00a0<strong>metaphase<\/strong>, the \u201cchange phase,\u201d all the chromosomes are aligned in a plane called the <strong>metaphase plate<\/strong>, or the equatorial plane, midway between the two poles of the cell. The sister chromatids are still tightly attached to each other by cohesin proteins. At this time, the chromosomes are maximally condensed.\r\n\r\nDuring\u00a0<strong>anaphase<\/strong>, the \u201cupward phase,\u201d the cohesin proteins degrade, and the sister chromatids separate at the centromere. Each chromatid, now called a chromosome, is pulled rapidly toward the centrosome to which its microtubule is attached. The cell becomes visibly elongated (oval shaped) as the polar microtubules slide against each other at the metaphase plate where they overlap.\r\n\r\nDuring\u00a0<strong>telophase<\/strong>, the \u201cdistance phase,\u201d the chromosomes reach the opposite poles and begin to decondense (unravel), relaxing into a chromatin configuration. The mitotic spindles are depolymerized into tubulin monomers that will be used to assemble cytoskeletal components for each daughter cell. Nuclear envelopes form around the chromosomes, and nucleosomes appear within the nuclear area.\r\n\r\nThe activity below will walk you through mitosis\u2014providing you with the chance to review the different steps of the process\u00a0and how they work together.\r\n\r\n<iframe src=\"https:\/\/www.oppia.org\/embed\/exploration\/q4NBr1JG7Qrt\" width=\"700\" height=\"950\"><\/iframe>\r\n\r\n<a href=\".\/the-steps-of-mitosis\/\" target=\"_blank\" rel=\"noopener\">Click here for a text-only version of the activity.<\/a>\r\n<div class=\"textbox tryit\">\r\n<h3>Try It<\/h3>\r\nhttps:\/\/assess.lumenlearning.com\/practice\/ca46de5c-d8d1-4178-b2ac-ad2d54eae8ec\r\n<\/div>","rendered":"<div class=\"textbox learning-objectives\">\n<h3>Learning Outcomes<\/h3>\n<ul>\n<li>Identify the characteristics and stages of mitosis<\/li>\n<\/ul>\n<\/div>\n<p>The mitotic phase (also known as M phase) is a multistep process during which the duplicated chromosomes are aligned, separated, and move into two new, identical daughter cells. The first portion of the mitotic phase is called\u00a0<strong>karyokinesis<\/strong>, or nuclear division. The second portion of the mitotic phase, called cytokinesis, is the physical separation of the cytoplasmic components into the two daughter cells.<\/p>\n<h2>Karyokinesis (Mitosis)<\/h2>\n<p>Karyokinesis, also known as mitosis, is divided into a series of phases\u2014prophase, prometaphase, metaphase, anaphase, and telophase\u2014that result in the division of the cell (Figure\u00a01).<\/p>\n<figure data-id=\"fig-ch10_02_02real\">\n<div style=\"width: 908px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"30715\" class=\"\" title=\"credit \u201cmitosis drawings\u201d: modification of work by Mariana Ruiz Villareal; credit \u201cmicrographs\u201d: modification of work by Roy van Heesbeen; credit \u201ccytokinesis micrograph\u201d: Wadsworth Center\/New York State Department of Health; scale-bar data from Matt Russell\" src=\"https:\/\/openstax.org\/resources\/a4eaf13f166b21e46b42467ac67eb6a949a76560\" alt=\"This diagram shows the five phases of mitosis and cytokinesis. During prophase, the chromosomes condense and become visible, spindle fibers emerge from the centrosomes, the nuclear envelope breaks down, and the nucleolus disappears. During prometaphase, the chromosomes continue to condense and kinetochores appear at the centromeres. Mitotic spindle microtubules attach to the kinetochores, and centrosomes move toward opposite poles. During metaphase, the mitotic spindle is fully developed, and centrosomes are at opposite poles of the cell. Chromosomes line up at the metaphase plate and each sister chromatid is attached to a spindle fiber originating from the opposite pole. During anaphase, the cohesin proteins that were binding the sister chromatids together break down. The sister chromatids, which are now called chromosomes, move toward opposite poles of the cell. Non-kinetochore spindle fibers lengthen, elongating the cell. During telophase, chromosomes arrive at the opposite poles and begin to decondense. The nuclear envelope reforms. During cytokinesis in animals, a cleavage furrow separates the two daughter cells. In plants, a cell plate separates the two cells.\" width=\"898\" height=\"743\" data-media-type=\"image\/png\" \/><\/p>\n<p class=\"wp-caption-text\">Figure\u00a01. <strong>Stages of mitosis<\/strong>. Karyokinesis (or mitosis) is divided into five stages\u2014prophase, prometaphase, metaphase, anaphase, and telophase. The pictures at the bottom were taken by fluorescence microscopy (hence, the black background) of cells artificially stained by fluorescent dyes: blue fluorescence indicates DNA (chromosomes) and green fluorescence indicates microtubules (spindle apparatus).<\/p>\n<\/div>\n<\/figure>\n<p>During\u00a0<strong>prophase<\/strong>, the \u201cfirst phase,\u201d the nuclear envelope starts to dissociate into small vesicles, and the membranous organelles (such as the Golgi complex or Golgi apparatus, and endoplasmic reticulum) fragment and disperse toward the periphery of the cell. The nucleolus disappears (disperses). The centrosomes begin to move to opposite poles of the cell. Microtubules that will form the mitotic spindle extend between the centrosomes, pushing them farther apart as the microtubule fibers lengthen. The sister chromatids begin to coil more tightly with the aid of <strong>condensin<\/strong> proteins and become visible under a light microscope.<\/p>\n<div id=\"attachment_1801\" style=\"width: 410px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1801\" class=\"wp-image-1801\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/110\/2016\/05\/03205004\/Figure_10_02_03.jpg\" alt=\"This illustration shows two sister chromatids. Each has a kinetochore at the centromere, and mitotic spindle microtubules radiate from the kinetochore.\" width=\"400\" height=\"293\" \/><\/p>\n<p id=\"caption-attachment-1801\" class=\"wp-caption-text\">Figure\u00a02. During prometaphase, mitotic spindle microtubules from opposite poles attach to each sister chromatid at the kinetochore. In anaphase, the connection between the sister chromatids breaks down, and the microtubules pull the chromosomes toward opposite poles.<\/p>\n<\/div>\n<p>During <strong>prometaphase<\/strong>, the \u201cfirst change phase,\u201d many processes that were begun in prophase continue to advance. The remnants of the nuclear envelope fragment. The mitotic spindle continues to develop as more microtubules assemble and stretch across the length of the former nuclear area. Chromosomes become more condensed and discrete. Each sister chromatid develops a protein structure called a kinetochore in the centromeric region (Figure\u00a02). The proteins of the kinetochore attract and bind mitotic spindle microtubules. As the spindle microtubules extend from the centrosomes, some of these microtubules come into contact with and firmly bind to the kinetochores. Once a mitotic fiber attaches to a chromosome, the chromosome will be oriented until the kinetochores of sister chromatids face the opposite poles. Eventually, all the sister chromatids will be attached via their kinetochores to microtubules from opposing poles. Spindle microtubules that do not engage the chromosomes are called polar microtubules. These microtubules overlap each other midway between the two poles and contribute to cell elongation. Astral microtubules are located near the poles, aid in spindle orientation, and are required for the regulation of mitosis.<\/p>\n<p>During\u00a0<strong>metaphase<\/strong>, the \u201cchange phase,\u201d all the chromosomes are aligned in a plane called the <strong>metaphase plate<\/strong>, or the equatorial plane, midway between the two poles of the cell. The sister chromatids are still tightly attached to each other by cohesin proteins. At this time, the chromosomes are maximally condensed.<\/p>\n<p>During\u00a0<strong>anaphase<\/strong>, the \u201cupward phase,\u201d the cohesin proteins degrade, and the sister chromatids separate at the centromere. Each chromatid, now called a chromosome, is pulled rapidly toward the centrosome to which its microtubule is attached. The cell becomes visibly elongated (oval shaped) as the polar microtubules slide against each other at the metaphase plate where they overlap.<\/p>\n<p>During\u00a0<strong>telophase<\/strong>, the \u201cdistance phase,\u201d the chromosomes reach the opposite poles and begin to decondense (unravel), relaxing into a chromatin configuration. The mitotic spindles are depolymerized into tubulin monomers that will be used to assemble cytoskeletal components for each daughter cell. Nuclear envelopes form around the chromosomes, and nucleosomes appear within the nuclear area.<\/p>\n<p>The activity below will walk you through mitosis\u2014providing you with the chance to review the different steps of the process\u00a0and how they work together.<\/p>\n<p><iframe loading=\"lazy\" src=\"https:\/\/www.oppia.org\/embed\/exploration\/q4NBr1JG7Qrt\" width=\"700\" height=\"950\"><\/iframe><\/p>\n<p><a href=\".\/the-steps-of-mitosis\/\" target=\"_blank\" rel=\"noopener\">Click here for a text-only version of the activity.<\/a><\/p>\n<div class=\"textbox tryit\">\n<h3>Try It<\/h3>\n<p>\t<iframe id=\"assessment_practice_ca46de5c-d8d1-4178-b2ac-ad2d54eae8ec\" class=\"resizable\" src=\"https:\/\/assess.lumenlearning.com\/practice\/ca46de5c-d8d1-4178-b2ac-ad2d54eae8ec?iframe_resize_id=assessment_practice_id_ca46de5c-d8d1-4178-b2ac-ad2d54eae8ec\" frameborder=\"0\" style=\"border:none;width:100%;height:100%;min-height:300px;\"><br \/>\n\t<\/iframe>\n<\/div>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-2388\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Biology 2e. <strong>Provided by<\/strong>: OpenStax. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/cnx.org\/contents\/185cbf87-c72e-48f5-b51e-f14f21b5eabd@10.8\">http:\/\/cnx.org\/contents\/185cbf87-c72e-48f5-b51e-f14f21b5eabd@10.8<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em>. <strong>License Terms<\/strong>: Access for free at https:\/\/openstax.org\/books\/biology-2e\/pages\/1-introduction<\/li><li>Mitosis diagram. <strong>Authored by<\/strong>: Marek Kultys. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Mitosis_diagram.jpg\">https:\/\/commons.wikimedia.org\/wiki\/File:Mitosis_diagram.jpg<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA: Attribution-ShareAlike<\/a><\/em><\/li><li>Mitosis. <strong>Provided by<\/strong>: Lumen Learning. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/www.oppia.org\/explore\/q4NBr1JG7Qrt\">https:\/\/www.oppia.org\/explore\/q4NBr1JG7Qrt<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA: Attribution-ShareAlike<\/a><\/em><\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">Public domain content<\/div><ul class=\"citation-list\"><li>Modification of Mitosis cells sequence. <strong>Authored by<\/strong>: LadyofHats. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Mitosis_cells_sequence.svg\">https:\/\/commons.wikimedia.org\/wiki\/File:Mitosis_cells_sequence.svg<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/about\/pdm\">Public Domain: No Known Copyright<\/a><\/em><\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section>","protected":false},"author":17,"menu_order":7,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Biology 2e\",\"author\":\"\",\"organization\":\"OpenStax\",\"url\":\"http:\/\/cnx.org\/contents\/185cbf87-c72e-48f5-b51e-f14f21b5eabd@10.8\",\"project\":\"\",\"license\":\"cc-by\",\"license_terms\":\"Access for free at https:\/\/openstax.org\/books\/biology-2e\/pages\/1-introduction\"},{\"type\":\"cc\",\"description\":\"Mitosis diagram\",\"author\":\"Marek Kultys\",\"organization\":\"\",\"url\":\"https:\/\/commons.wikimedia.org\/wiki\/File:Mitosis_diagram.jpg\",\"project\":\"\",\"license\":\"cc-by-sa\",\"license_terms\":\"\"},{\"type\":\"pd\",\"description\":\"Modification of Mitosis cells sequence\",\"author\":\"LadyofHats\",\"organization\":\"\",\"url\":\"https:\/\/commons.wikimedia.org\/wiki\/File:Mitosis_cells_sequence.svg\",\"project\":\"\",\"license\":\"pd\",\"license_terms\":\"\"},{\"type\":\"cc\",\"description\":\"Mitosis\",\"author\":\"\",\"organization\":\"Lumen Learning\",\"url\":\"https:\/\/www.oppia.org\/explore\/q4NBr1JG7Qrt\",\"project\":\"\",\"license\":\"cc-by-sa\",\"license_terms\":\"\"}]","CANDELA_OUTCOMES_GUID":"598964f5-fafd-4b8e-80f0-9def8d693c17, f012e03e-80fb-4bf6-82dd-1391b12ca609","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-2388","chapter","type-chapter","status-publish","hentry"],"part":205,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/pressbooks\/v2\/chapters\/2388","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/wp\/v2\/users\/17"}],"version-history":[{"count":19,"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/pressbooks\/v2\/chapters\/2388\/revisions"}],"predecessor-version":[{"id":5943,"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/pressbooks\/v2\/chapters\/2388\/revisions\/5943"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/pressbooks\/v2\/parts\/205"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/pressbooks\/v2\/chapters\/2388\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/wp\/v2\/media?parent=2388"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/pressbooks\/v2\/chapter-type?post=2388"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/wp\/v2\/contributor?post=2388"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/wp\/v2\/license?post=2388"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}