{"id":783,"date":"2023-12-07T23:13:13","date_gmt":"2023-12-07T23:13:13","guid":{"rendered":"https:\/\/cellandcelldivision.com\/?p=783"},"modified":"2023-12-07T23:13:14","modified_gmt":"2023-12-07T23:13:14","slug":"page-190","status":"publish","type":"post","link":"https:\/\/cellandcelldivision.com\/?p=783","title":{"rendered":"Page 190"},"content":{"rendered":"\n<p>In their review Dodge and Vickerman (1980) differentiate four types of<br>mitosis.<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Closed mitosis with internal division spindle.<\/strong> In this case all<br>the time the nuclear envelope remains intact, and the dividing apparatus<br>is located within the nucleus. This type of mitosis is characteristic of a<br>number of prokaryotes, unicellular algae, euglena, paramecia, etc. Up to<br>now no fibres (microtubules), forming a division spindle, are observed in<br>them.<\/li>\n\n\n\n<li><strong>Close mitosis with external division spindle.<\/strong> In this type of<br>division, from the very beginning of the process fascicles of microtubes<br>are formed on the one side of nucleus. After that, they through channels<br>and tunnels penetrate in the nucleus, and the chromosomes attach to<br>them. No centrioles or polar small bodies are observed. During<br>anaphase the nucleus elongates and the chromosomes are separated,<br>without any break down of the nuclear envelope. It is observed in<br>different species of free-living and parasitic dinoflagellates.<\/li>\n\n\n\n<li><strong>Semi-open mitosis<\/strong>. In this case, the nuclear envelope remains<br>substantially intact, but the gaps or polar fenestrae developed in it make<br>possible the intervenrtion of cytoplasmic mitotic centres in the processes<br>of nuclear division. Such type of mitosis is described in different species<br>of green algae and fungi. In some of them one can already observe<br>centrioles or polar small bodies and small kinetochores through which<br>the chromosomes attach to the microtubules, and also shapely nucleoli.<br>The very mitosis is realized with spiralizing the chromosomes, break<br>down of the nucleolus, and inside the nucleus a structure resembling<br>division spindle appears. During anaphase the chromosomes are<br>distributed, the nucleus elongates, followed by dividing in two. The old<br>nuclear envelope can breaks down and participate in the building nuclear<br>envelopes of the newly obtained nuclei.\n<ul class=\"wp-block-list\">\n<li><strong>Open mitosis.<\/strong> This is the main type of division in higher<br>eukaryotes. Naturally there are some differences in the individual plant<br>and animal organisms, related to the organization of dividing structures.<br>A peculiarity is, that in all cases the nuclear envelope break down<br>already at the time of prometaphase and then the processes are realized<br>openly in cytoplasm.<br>Using the results of the investigations made on different prokaryotic<br>and eukaryotic organisms described in the literature, Alberts et al. (1986)<br>have made a scheme, illustrating some stages of the mitotic spindle (Fig.<br>3\u201314).<br>One variety of mitosis is meiosis called also <strong>reducing division<\/strong>. It is<br>observed by forming the mature sexual cells in higher plant and animal<br>organisms, normally having in their vegetative cells a diploid set of<br>chromosomes obtained as a result of fertilization. Its biological essence<br>lies in transforming diploid nucleus (2n) in haploid (1n) one, and<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>In their review Dodge and Vickerman (1980) differentiate four types ofmitosis.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[6],"tags":[],"class_list":["post-783","post","type-post","status-publish","format-standard","hentry","category-book"],"_links":{"self":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/783","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=783"}],"version-history":[{"count":1,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/783\/revisions"}],"predecessor-version":[{"id":808,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/783\/revisions\/808"}],"wp:attachment":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=783"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=783"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=783"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}