{"id":33,"date":"2024-04-04T08:53:22","date_gmt":"2024-04-04T05:53:22","guid":{"rendered":"https:\/\/sisu.ut.ee\/biogymnaasium\/3-organismide-areng-ehk-ontogenees\/"},"modified":"2024-04-04T08:54:46","modified_gmt":"2024-04-04T05:54:46","slug":"3-organismide-areng-ehk-ontogenees","status":"publish","type":"page","link":"https:\/\/sisu.ut.ee\/biogymnaasium\/3-organismide-areng-ehk-ontogenees\/","title":{"rendered":"3. Organismide areng ehk ontogenees"},"content":{"rendered":"

\n\t\"arengu\n<\/p>\n

\n\tM\u00f5isted
Ontogenees\u00a0<\/strong>on organismide areng viljastumisest kuni surmani.
Embr\u00fcogenees<\/strong>\u00a0ehk looteline areng toimub viljastumisest kuni eraldumiseni emasorganismist (nt koorumine v\u00f5i s\u00fcndimine).
Postembe\u00fcogenees<\/strong>\u00a0ehk lootej\u00e4rgne ehk s\u00fcnnij\u00e4rgne areng on s\u00fcnnist kuni surmani.\n<\/p>\n

\n\tOtsene areng<\/strong>\u00a0esineb juhul, kui j\u00e4rglane meenutab t\u00e4iskasvanud isendit ja ei tee l\u00e4bi eriiilmelisi arenguetappe (nt roomajad, linnud ja imetajad).\u00a0\n<\/p>\n

\n\tT\u00e4ismoone<\/strong>\u00a0on teatud\u00a0putukate<\/a>\u00a0arenguts\u00fckkel, mis koosneb neljast staadiumist:\u00a0\u00a0muna<\/a>\u00a0\u2013\u00a0vastne<\/a>\u00a0\u2013\u00a0nukk<\/a>\u00a0\u2013\u00a0valmik<\/a>\u00a0(nt\u00a0liblikalised<\/a>,\u00a0kahetiivalised<\/a>,\u00a0mardikalised<\/a>).\u00a0\n<\/p>\n

\n\tVaegmoone<\/strong><\/a>\u00a0\u00a0erineb t\u00e4ismooondest selle poolest, et vaegmoondes puudub nukustaadium (nt. sihktiivalised, t\u00e4ilised ja prussakalised,\u00a0ainu\u00f5\u00f5ssed<\/a>,\u00a0ussid<\/a>,\u00a0v\u00e4hid<\/a>,\u00a0kahepaiksed<\/a>, enamik\u00a0kalu<\/a>).\n<\/p>\n

\n\tViljastumine<\/strong>\u00a0ehk\u00a0fertilisatsioon<\/strong>\u00a0\u00a0on\u00a0sugulise sigimise<\/a>\u00a0p\u00f5hiprotsess, milles eriomased rakud (v\u00f5i\u00a0rakutuumad<\/a>) \u00fchinevad\u00a0s\u00fcgoodiks<\/strong><\/a>. Viljastumisel toimub enamasti kahe isendi (samast liigist) sugurakkude ehk\u00a0gameetide<\/a>\u00a0liitumine\u00a0\u00a0ja seel\u00e4bi ka nende\u00a0genoomide<\/a>\u00a0\u00fchinemine.\n<\/p>\n

\n\t\u00a0\n<\/p>\n

\n\tOntogenees<\/strong>\u00a0ehk\u00a0isendiareng\u00a0on \u00fcksiku\u00a0organismi<\/a>\u00a0areng organismi tekkimisest (viljastunud munarakust<\/a>) kuni\u00a0\u00a0loomuliku surmani<\/a>. Individuaalne areng jagatakse kaheks etapiks:\u00a01) embr\u00fcogenees ehk looteline areng (viljastumisest kuni s\u00fcnnini v\u00f5i emasorganismist eraldumiseni);
\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a02) postembr\u00fcogenees ehk lootej\u00e4rgne (s\u00fcnnij\u00e4rgne) areng.<\/p>\n

Sugurakkude tekkimine<\/strong>
Organismi s\u00fcnnieelsele arengule eelneb ka sugurakkude valmimine meioosi teel. Munarakkude tekkeprotsess on ovogenees ja seemnerakkude ehk spermide tekkeprotsessi nimetetakse spermatogeneesiks, mis on t\u00e4psemalt kirjeldatud eelmises alapeat\u00fckis.\n<\/p>\n

\n\t\u00a0\n<\/p>\n\n\n\n\n\n
\n\t\tSugurakkude tekkimine
\n\t<\/caption>\n
\n\t\t\t\tMitoos, millele j\u00e4rgneb\n\t\t\t<\/th>\n\n\t\t\t\tMeioos\n\t\t\t<\/th>\n<\/tr>\n<\/thead>\n
\n\t\t\t\t\"Mitoos\"\n\t\t\t<\/th>\n\n\t\t\t\t\"Meioos\"\n\t\t\t<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\n<\/h4>

Viljastumine\u00a0<\/strong>
\n\n<\/p>

\n\tKitsamas m\u00f5ttes on sugurakkude tuumade \u00fchinemine, mille tulemusena annnavad m\u00f5lemad sugurakud oma DNA j\u00e4rglastele edasi, vanemaid v\u00f5ib olla \u00fcks (hermafrodiit) v\u00f5i kaks.\n<\/p>\n\n\n\n\n\n
\n\t\t\t\tKehav\u00e4line viljastumine\n\t\t\t<\/th>\n\n\t\t\t\tKehasisene viljastumine\n\t\t\t<\/th>\n<\/tr>\n<\/thead>\n
\n
    \n
  • \n\t\t\t\t\t\tkaladel\n\t\t\t\t\t<\/li>\n
  • \n\t\t\t\t\t\tkahepaiksetel\n\t\t\t\t\t<\/li>\n
  • \n\t\t\t\t\t\tloimuritel\n\t\t\t\t\t<\/li>\n
  • \n\t\t\t\t\t\tv\u00e4hilaadsetel\n\t\t\t\t\t<\/li>\n
  • \n\t\t\t\t\t\tjt veeloomadel\n\t\t\t\t\t<\/li>\n<\/ul>\n<\/td>\n
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