{"id":851,"date":"2023-12-11T21:36:47","date_gmt":"2023-12-11T21:36:47","guid":{"rendered":"https:\/\/cellandcelldivision.com\/?p=851"},"modified":"2023-12-11T21:36:47","modified_gmt":"2023-12-11T21:36:47","slug":"page-206","status":"publish","type":"post","link":"https:\/\/cellandcelldivision.com\/?p=851","title":{"rendered":"Page 206"},"content":{"rendered":"\n

factors \u2014 nutrient substances, temperature, pH of the medium, potential
genetic and energetic possibilities of the cells, etc. It is difficult to ensure
them simultaneously, especially in natural conditions. For example, in
case of changing only one of the factors necessary for the development
of an optimum synchronized culture of Scenedesmus acutus<\/em> (temperature
below 20\u00b0C or pH below 6) under equal other conditions, the cells begin
to form two or three nuclei, instead of four, eight or more, and divide very
slowly.
2. What is the way of realizing the formation of daughter cells and the
distribution of cytoplasm in the mother cell, i.e. whether it occurs
immediately after each nuclear division or after reaching a \u201ccrucial\u201d
number of nuclei, when the mother cell will start releasing the new
generation of daughter cells?
This questions has been attracted the attention already at the time of
Smith (1914), then of Mazia (1963), Pickett-Heaps (1975) and many other
investigators. But even now it is still unclear. According to Pickett-Heaps
\u201cthe divisions that occur after the completion of mitosis have proved to be
most difficult regarding ultrastructure studies and they are largely resisted
analyses\u201d.
3. What are the reasons and mechanisms determining the \u201cdecision\u201d
of a nucleus to start a subsequent division or not to divide and form a
daughter cell?
This is a real \u201cmystery\u201d of cell biology, and it will be very hard to be
solved. Here is the key to the asynchronous division approved in the
course of evolution. In my opinion it is realized asynchronously,
consecutively on the principle \u201cnucleus \u2014 cell\u201d. Violating this principle
leads to multinuclear cells, mentioned in the previous Section 3. 3 \u2014
symplasts, osteoclasts, HeLa-cells, etc., where cell division does not
proceed normally.
Accepting the asynchronous nuclear and cell division as a natural
biological process (Nicolov, 1997 a) gives rise to the necessity to change
the trends and methods of cell research. The reason for such a mode of
division should be looked for mainly in the genetic material, in eventual
differences between the copies of DNA-replication and in the energetic
possibilities of cells, acquired as a result of the metabolic processes in
them.
Let pay attention to the energetic aspect of the question, that could
be the decisive evolutionary factor determining the way of realizing the
reproduction of nuclei and cells in time. It is known that every biological
process needs some energy. Undoubtedly, nuclear and cell division is
connected with such processes. If in one cell of Scenedesmus acutus<\/em> or
Clorella vulgaris <\/em>there are four or eight nuclei and they are to reproduce
simultaneously, i.e. synchronously in eight or sixteen, respectively, much
more energy for a given time will be necessary, than if that proceeds<\/p>\n","protected":false},"excerpt":{"rendered":"

factors \u2014 nutrient substances, temperature, pH of the medium, potentialgenetic and energetic possibilities of the cells, etc. It is difficult to ensurethem simultaneously, especially in natural conditions. For example, incase of changing only one of the factors necessary for the developmentof an optimum synchronized culture of Scenedesmus acutus (temperaturebelow 20\u00b0C or pH below 6) under […]<\/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-851","post","type-post","status-publish","format-standard","hentry","category-book"],"_links":{"self":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/851","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=851"}],"version-history":[{"count":2,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/851\/revisions"}],"predecessor-version":[{"id":857,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/851\/revisions\/857"}],"wp:attachment":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=851"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=851"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=851"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}