Lizzy

I am Masingita Lizzy Maluleke.I did Bachelor degree of Enviremental Sciences at the University of Venda for science and technology majored with Geography and Ecology and Resourse Managenment.I am presantly doing honours with the university of the Western Cape in Ecological Informatics.

Monday, May 15, 2006

COMPARISON OF MODE OF REPRODUCTION BETWEEN THE PLACENTAL MAMMALS AND MARSUPIALS


The placental mammals are female vertebrate animals having an organ part where the baby grows before it is born. Marsupials are invertebrate animals and placental mammals are vertebrate animals. There are differences between the marsupials and placental mammals during the process in which the babies grow inside the body of their mother before they born and this process is known as gestation. The development of an embryo in marsupials vertebrate animals is isolated from body of their mother by the amniotic membrane.

The differences between the marsupials and placental mammals are their rate of gestation. I marsupials the mode of their reproduction is more difficult compared to the placental mammals meaning that their reproductions is not difficult. Embryo becomes a new organism during the process of the fertilization and auto immune system from their mother will assault it. The amniotic membrane work together with the mother and it also protect them not to be assaulted.

The short and long gestation in marsupial vertebrate occurs as differ to the placental mammals. The short gestation qualified to the development of the yolk type reproduction. The longer gestation in marsupials qualified to the fully developed off spring. Marsupials and placental mammals also differ during their birth. The birth rate in marsupials occurs at the early stage. It takes a week or a mouth for unborn organism to pouch and attached to a teat depending on that particular species. In placental mammals the birth rate occurs at late stage. The process of gestation in off spring starts to full develop.


The other differences between placental and marsupial’s reproduction occurs in the mode reproduction and any pattern. The pregnancy in marsupials does not interrupt the development of the oestrus cycle and the pregnancy in placental interrupt the development of the oestrus cycle. The reproduction in marsupials it said to be full developed and there is no combination in both right and left of marsupial’s vaginae to from a single body through psyeodoraraginal canal.


In marsupials the right and left uterus are not complex compared to in plantation meaning that the right and left uterus is complex. During the embryo in marsupials mammals the process of development female reproductive tract is different compared to the one which is found in the placental mammals. In marsupial, the marsupiums develop in females in order to look after the babies. The male in marsupials have double penis and their scrotum is found in the anterior part of the penis. In placental mammals the scrotum is found at the posterior at the end of the penis.


There are differences between the placental mammals and the marsupials on their reproduction anatomy and pattern because marsupials are invertebrate mammals while as placental mammals are vertebrate mammals. They are also differences during their gestation. Their birth occurs at different times, in marsupials’ birth occurs earlier compare to placental meaning that in placental birth occurs later. In marsupials the pregnancy does not interrupt the oestrus cycle and in placental the pregnancy is interrupt. The reproduction in marsupials it said to be full developed compared to in placental mammals.


Reference:

Wikipedia contributors. Placental [Internet]. Wikipedia, the free encyclopaedia, 2006 May 07, 18:21 UTC [Cited 2006 May 12, 10:21]. Available from:
http://en.wikipedia.org/wiki/Placental

Wikipedia contributors. Marsupials [Internet]. Wkipedia, the free encyclopaedia, 2006 May 09, 17:16 UTC [Cited 2006 May 12, 11:10]. Available from: http://en.wikipedia.org/wiki/Marsupials



Lizzy Maluleke
CSIR PTA
0001
Cell number 072 351 8488
Tell [012] 841 2133
Fax [012] 842 3676
E-mail mmaluleke@csir.co.za
Weblog: http://mmaluleke.blogspot.com

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