A choriovitelline placenta is a placenta formed by the yolk sac and chorion. In a choriovitelline placenta, the yolk sac fuses with the chorion and, subsequently, wrinkles develop that hold the embryo to the uterine wall, thus forming the choriovitelline placenta. The chorionic blood vessels are connected with the vitelline blood vessel of the yolk sac. [1]
It is a primitive type of placenta found in all marsupials. (However, bandicoots also have a chorioallantoic placenta.) A choriovitelline placenta also forms early in the development of some placental mammals before the chorioallantoic placenta forms and the choriovitelline placenta is resorbed.
References[edit]
- ^ Enders, A.C. (March 2009). "Reasons for Diversity of Placental Structure". Placenta. 30: 15–18. doi:10.1016/j.placenta.2008.09.018. PMID 19007983. Retrieved 2 July 2022.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction