{"id":549,"date":"2023-11-28T15:20:00","date_gmt":"2023-11-28T15:20:00","guid":{"rendered":"https:\/\/cellandcelldivision.com\/?p=549"},"modified":"2024-02-07T23:52:09","modified_gmt":"2024-02-07T23:52:09","slug":"page-92","status":"publish","type":"post","link":"https:\/\/cellandcelldivision.com\/?p=549","title":{"rendered":"Page 92"},"content":{"rendered":"\n<p class=\"has-text-align-center\">increase of ploidity (4, 8, 16, 32, 64, etc.), the chromatids remain bound to<br>one another and the so-called <strong>polythene chromosomes<\/strong> are obtained.<br>Sometimes the chromatid number in them is so high, that it is almost<br>impossible to differentiate between the individual chromosomes in the<br>nucleus.<br>Polythene chromosomes represent a particular case of polyploidy<br>since they permanently exist in an interphase, that is unfolded state which<br>renders them ideal for the study of their structural organization and<br>functions. They consist of consecutively arranged intensively stained discs<br>and light interdisc spaces. At certain moments some of the discs swell and<br>form spheric swellings denoted as <strong>puffs<\/strong>, the most typical of them called<br><strong>Balbiani rings<\/strong> after the name of their discoverer (Fig. 2\u201325). The<br>processes taking place in them are related to intensive RNA synthesis and<br>specific enzymes.<\/p>\n\n\n\n<p>image<\/p>\n\n\n\n<pre class=\"wp-block-verse has-text-align-center\">Figure 2\u201324. Set of four giant chromosomes from a cell of the salivary \r\ngland of <em>Chironomus tentans<\/em> (After Beermann and Clever, 1964). <\/pre>\n\n\n\n<p>image<\/p>\n\n\n\n<p>image<\/p>\n\n\n\n<pre class=\"wp-block-verse has-text-align-center\">Figure 2\u201325. Chromosome puffs in giant chromosomes from a salivary \ngland cell of <em>Chironomus tentans<\/em>. The larger of them are called Balbiani \r\nrings (After Beermann and Clever, 1964).<\/pre>\n\n\n\n<p class=\"has-text-align-center\">The lampbrush chromosomes (Fig. 2\u201326) are observed during the<br>meiosis in oocytes of fish, crabs, etc. Recently they have been provoking<br>certain interest from an evolutionary point of view after it has been<br>established that they are devoid of DNA or its content is very low in them.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>increase of ploidity (4, 8, 16, 32, 64, etc.), the chromatids remain bound toone another and the so-called polythene chromosomes are obtained.Sometimes the chromatid number in them is so high, that it is almostimpossible to differentiate between the individual chromosomes in thenucleus.Polythene chromosomes represent a particular case of polyploidysince they permanently exist in an interphase, [&hellip;]<\/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-549","post","type-post","status-publish","format-standard","hentry","category-book"],"_links":{"self":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/549","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=549"}],"version-history":[{"count":1,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/549\/revisions"}],"predecessor-version":[{"id":551,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/549\/revisions\/551"}],"wp:attachment":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=549"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=549"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=549"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}