Ina tasowa dabbobi masu shayarwa tayi? musamman dabbobi masu shayarwa

Dabbobi masu shayarwa (7 aji na nazarin wannan topic a cikin sashe na ilmin dabbobi) ya hada dukan dabbobi da cewa ciyar da matasa tare da madara. Tun da yake wannan ne mafi girma a aji na vertabrate, akwai da dama sukayi fassara a cikin wannan din hadin kai. Daya daga cikin su dogara ne a kan inda dabbobi masu shayarwa tayi tasowa. Wannan tambaya za mu yi la'akari a cikin daki-daki a cikin wannan labarin.

dabbobi masu shayarwa jinsunan

All dabbobi masu shayarwa suna iri guda ba mafi girma dabbobi. Kuma da mãtã, kuma mazan sun guda biyu gonads: da ovaries kuma testes, bi da bi. Sun bude waje musamman tashoshi. Domin duk waɗannan dabbobi ne halayyar kawai na ciki hadi. Duk da haka, daga inda masu tasowa dabbobi masu shayarwa tayi dogara a kan samuwar da ta kara ci gaba da matakin.

Wane ne yinotheria

M amma gaskiya: akwai dabbobi masu shayarwa cewa sa qwai. Suna da ake kira "yinotheria" da kuma samar da daya kadai naúrar - monotremes. Kuma ya mai suna haka saboda wadannan dabbobi suna da wata cloaca. Wannan shi ne wani m hali, halayyar da baya chordates. A cloaca ne guda bude a cikin abin da kayayyakin suke da daraja musayar urinary, narkewa kamar da kuma haihuwa tsarin.

Yinotheria sosai kima, sun hada da kawai 6 jinsunan. Su habitats - Australia tare da m tsibirin. Wakilainsu ne echidnas, platypus da kuma irin spiny anteaters. Su ba su da nonna da kuma madara ta hanyar da ducts na gland aka saki ga surface na fata. A kwiyakwiyanta yi lasa shi, ya zama gamsu.

Quite nadiri ne bayyanar da wadannan dabbobi. Echidna ne sosai kama da wani babban bushiya. Its tsawo da kuma kaifi needles ba kõme ba sai a gyara gashi ga kowa da kowa dabbobi masu shayarwa. Kasa su ne a Layer na wani m gashi. Kuma idan ka yi la'akari da cewa gaba, na daga cikin muzzle ne elongated a cikin proboscis kuma wata gabar jiki ne m fika tsara don digging, echidna kuma bai tuna fantastic ƙarancin dabba. Su mace Bears guda kwai. Su hankali adana shi a cikin folds na fata located a kan ventral sashi na jiki.

Platypus dubi quite daban-daban. By da muƙamin quite sauki tsammani cewa shi yana da fadi da kuma lebur hanci. A yatsunsu shirya yin iyo membrane, da wutsiya yana da wani flattened siffar, mukaddashin kamar flippers. Platypus kyankyasar kwan su qwai a cikin nests, wanda ya dace da kansu.

Wadannan dabbobi Subclass

Daga cikin wadannan dabbobi suna da, a kowa ne cewa su haifi zuwa rayuwa matasa sau daya, ba don kyankyasar kwan su, kamar tsuntsaye. Bã su da wani cloaca, da kuma ducts na narkewa kamar, haihuwa da kuma urinary tsarin bude raba, musamman tashoshin jiragen ruwa. Ya danganta da inda da dabbobi masu shayarwa tayi tasowa, rarrabe marsupials da placental dabbobi masu shayarwa.

Marsupial tawagar

Shi ne kuma hankula mazaunan Australian nahiyar. Suna halin da cewa da wuri inda masu tasowa dabbobi masu shayarwa tayi (kwai), suka bar sosai da sauri. Wannan shi ne domin sun gaba daya bace mahaifa. A sakamakon haka, matasa an haife m, kananan size, kuma ba su iya zaman kanta rayuwa. Bayan haihuwar wani lokaci su ne a cikin jakar fata, ma ayi a kan ventral sashi na jiki. Yana bude da kuma ducts na mammary gland.

A jariri ne don haka mai rauni, kuma m cewa da farko ba ma iya tsotse a kan nasu. Tsokoki gland spontaneously rage da kuma ta atomatik spurting zafi madara a bakin wani kananan marsupial dabba. Wakilai daga wadannan dabbobi su ne da farko dabbar kangaroo. Sun iya motsa a gudun game da 60 km / h.

Fairly kowa a Australia ne marsupial bear koalas da possums.

Placental cikinsa da dabbobi masu shayarwa tayi tasowa

A mafi girma ci gaba, kuma ta haka ne yada a fadin duniya, kai dabbobi masu shayarwa, da ya zauna cikin mahaifa, wanda aka samar a lokacin daukar ciki mahaifa. Yana binds uwar da kuma jaririn a lokacin daukar ciki. Bayan samuwar jini aka yi numfasawa da sinadarin gina jiki musayar. A sakamakon haka, a nan gaba jiki da aka bayar tare da dukkan muhimman sharuddan da yanayi, da kuma igiyar ciki bango an kare daga m muhalli da yanayi. Ya samu karfin isa ya zama nan da nan bayan haihuwar mai yiwuwa da kuma bayan wani gajeren lokaci zuwa mai zaman kanta zama. Yadda m wannan hali, ya ce adadin da matsayi na da rinjaye dabbobi na wannan jikin. Insectivores, jemagu, hakori, Lagomorphs, Artiodactyla, da dawakai, dabbobi masu cin nama, pinnipeds - wannan ba wani cikakken jerin raka'a cewa ne placental. Na'am, kuma mannyan birai, da suka hada da zamani look Homo sapiens, kai ta ci gaba da godiya ga gaban da wannan alama da.

Musamman dabbobi masu shayarwa: da amfani ko rashin amfani

Hakika, ci gaban da tayi a cikin mahaifa via mahaifa ne mafi m hanya. A da samuwar igiyar ciki bango da blastoderm tam Fused. Mahaifa yana yi duk abubuwa da suke a cikin uwa tasa ta jiki suna hawa zuwa cikin jikin yaro. A cikin mahaifa ya kasance ba ji tsoro na wani zazzabi canje-canje ba, kuma ba mazambata. Da sauƙi, oviparous ne a kasa m matsayi. Wannan ne bayyananne hujja. Hakika, qwai yana qunshe yawa na gina jiki zama dole domin ci gaba da amfrayo. Amma sun iya zama kyawawa ganima daga predatory dabbobi. Kuma idan akai la'akari da cewa matsakaicin yawan qwai 3-4, za a iya kullum za a bar ba tare da zurriyarsu. Sun marsupials aka haife ma underdeveloped. Alal misali, tsawon lokaci da ciki tsari a possum kawai makonni biyu. Babu shakka, a cikin irin wannan gajeren lokaci wani hadadden jiki ba shi da lokacin da za a kai ta dace mataki na ci gaba.

Saboda haka, ci gaban da dabbobi masu shayarwa yana da siffofin da cewa ba da damar hada su a cikin uku kungiyoyin, wanda kowannensu na da karbuwa siffofin: monotremes, marsupials da placental.