{"id":547,"date":"2023-11-28T15:26:00","date_gmt":"2023-11-28T15:26:00","guid":{"rendered":"https:\/\/cellandcelldivision.com\/?p=547"},"modified":"2024-02-07T23:54:38","modified_gmt":"2024-02-07T23:54:38","slug":"page-94","status":"publish","type":"post","link":"https:\/\/cellandcelldivision.com\/?p=547","title":{"rendered":"Page 94"},"content":{"rendered":"\n

phenotypic changes (Bridges, 1935\u201438), and the results from a number of
studies in that trend have created the notion of the disc as an independent
functional unit, i.e. a gene determining a definite hereditary feature or
property of a single cell or organism. Gene maps of the polythene
chromosomes of a number of research objects have been constructed and
in-detail calculations of the gene quantity and the controlled by them features
have been carried out both for the individual chromosomes and the genome
as a whole. So, for example, the genome of Drosophila melanogaster<\/em> was
initially calculated to be about 10 000 and after that reduced to 5000 genes
encoding the synthesis of 5000 proteins of medium size, consisting of 400
amino acid residues each. Such calculations have been performed for many
other unicellular and multicellular organisms, man including whose genome
was calculated to be 6 million genes corrected to 3 million later.
Gene maps of the loci of different genes have also been made. Studying
the fine structure and topography of a small portion of the chromosome of the
phage T4, Benzer (1961) has established an irregular distribution of the point
mutations along its length (Fig. 2\u201327). The author has suggested a
nomenclature of his, dividing the chromosomes into cistrons<\/strong> (A, B, etc.) which
correspond to the already firmly established notion of the gene, and the cistrone
was divided into sites. He has also introduced the terms muton<\/strong> (the smallest
unit of mutation) and recon<\/strong> (the smallest unit of recombination).<\/p>\n\n\n\n

image<\/p>\n\n\n\n

Figure 2\u201327. Topographic map of the rII region of phage T4 for \r\nspontaneous mutations (After Benzer, 1961). \r\nEach square corresponds to one mutation event. In most cases they are \r\nnot established. Different sites, in which the area rII can be divided by \r\nmeans of deletions, are marked by the symbols A1a, A1b1, A1b2, etc. In\nsome sites, so-called \u201chot spots\u201d, the mutations are much more than in \r\nothers. Dotted line shows the borders of the cystrons A and B. <\/pre>\n","protected":false},"excerpt":{"rendered":"
phenotypic changes (Bridges, 1935\u201438), and the results from a number ofstudies in that trend have created the notion of the disc as an independentfunctional unit, i.e. a gene determining a definite hereditary feature orproperty of a single cell or organism. Gene maps of the polythenechromosomes of a number of research objects have been constructed andin-detail […]<\/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-547","post","type-post","status-publish","format-standard","hentry","category-book"],"_links":{"self":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/547","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=547"}],"version-history":[{"count":1,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/547\/revisions"}],"predecessor-version":[{"id":553,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/547\/revisions\/553"}],"wp:attachment":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=547"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=547"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=547"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}