{"id":24038,"date":"2024-06-07T02:20:47","date_gmt":"2024-06-06T20:50:47","guid":{"rendered":"https:\/\/vajiramandravi.com\/current-affairs\/?p=24038"},"modified":"2025-04-07T06:41:14","modified_gmt":"2025-04-07T01:11:14","slug":"placental-mammals","status":"publish","type":"post","link":"https:\/\/vajiramandravi.com\/current-affairs\/placental-mammals\/","title":{"rendered":"What are Placental Mammals?"},"content":{"rendered":"<h2>About Placental Mammals:<\/h2>\n<ul>\n<li>A placental mammal is an <strong>animal that has a placenta.<\/strong><\/li>\n<\/ul>\n<p>o The placenta is a <strong>vascular organ formed during gestation of female<\/strong> mammals (except for monotremes and marsupials), built up of maternal and fetal tissues jointly, and which serves for the <strong>transport of nutrient<\/strong> substances f<strong>rom the mother to the fetu<\/strong>s and to <strong>eliminate fetal waste products<\/strong>.<\/p>\n<ul>\n<li>Placental mammals <strong>carry their fetus in the uterus until they are born<\/strong> at an advanced stage.<\/li>\n<li>The <strong>young get<\/strong> their <strong>nourishment through a placenta<\/strong> before birth. The placenta delivers nutrients and oxygen to the fetus in the uterus.<\/li>\n<li>The <strong>placenta permits a long period of fetal growth in the uterus<\/strong>. As a result, the <strong>fetus can become large and mature before birth.<\/strong><\/li>\n<li>Classified under the <strong>subclass Eutheria<\/strong>, placental mammals have 4,000 identified species.<\/li>\n<li>Fossil evidence shows that the <strong>first placental mammals evolved<\/strong> between about 163 million and 157 million years ago <strong>during the Jurassic Period<\/strong> (201.3 million to about 145 million years ago).<\/li>\n<li>The placentals <strong>include all living mammals except marsupials and monotremes<\/strong> (egg-laying mammals).\n<ul>\n<li><strong>Marsupials and monotremes have <\/strong>a <strong>less-developed, less-efficient<\/strong> type of <strong>placenta<\/strong> that limits the gestation period.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><strong>What are Marsupials?<\/strong><\/p>\n<ul>\n<li>Marsupials are a group of mammals that are known for <strong>giving birth to relatively undeveloped young,<\/strong> which <strong>then continue to<\/strong> grow and <strong>develop outside the womb<\/strong>, <strong>typically in a pouch.<\/strong><\/li>\n<li>Marsupials have a <strong>short-lived placenta<\/strong> that nourishes their young for just a few days before they\u2019re born, the rest of their nutrition coming from the mother\u2019s teats inside the pouch.<\/li>\n<li>Marsupials have an <strong>extra pubic bone<\/strong>, the epipubic bone, <strong>to support their pouch.<\/strong><\/li>\n<li>There are over <strong>330 species of marsupials<\/strong>. Around <strong>two-thirds of them live in Australia<\/strong>. The other third live mostly in South America.<\/li>\n<li><strong>Examples: Kangaroos, Koalas, Opossums, etc.<\/strong><\/li>\n<\/ul>\n<hr \/>\n<h3>Q1: What is brown fat?<\/h3>\n<p>Brown fat, also called brown adipose tissue, helps maintain your body temperature when you get too cold. It\u2019s the same fat that bears use to stay warm when they hibernate. Babies are born with a lot of brown fat behind their shoulder blades. Newborns can\u2019t shiver, which is one of the ways the body creates heat. Brown fat acts as a built-in heater.\u00a0<\/p>\n<p><strong>Source: <\/strong><a href=\"https:\/\/phys.org\/news\/2024-06-marsupials-key-heater-mammals.html\" target=\"_blank\" rel=\"nofollow noopener\">Marsupials key to discovering the origin of heater organs in mammals<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>A placental mammal is an animal that has a placenta.<\/p>\n","protected":false},"author":5,"featured_media":24039,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":{"0":"post-24038","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-upsc-prelims-current-affairs","8":"no-featured-image-padding"},"acf":[],"_links":{"self":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts\/24038","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/comments?post=24038"}],"version-history":[{"count":0,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts\/24038\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/media\/24039"}],"wp:attachment":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/media?parent=24038"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/categories?post=24038"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/tags?post=24038"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}