How is a chorioallantoic placenta different from a choriovitelline.pdf

How is a chorioallantoic placenta different from a choriovitelline placenta? Give an example of
an animal or group of animals that depend on each.
How is a chorioallantoic placenta different from a choriovitelline placenta? Give an example of
an animal or group of animals that depend on each.
Solution
1) The family Peramelidae/bandicoots has a chorioallantoic placenta. The rest of the marsupials
have a choriovitelline placenta.
2) The choriovitelline placenta is less vascularized than the chorioallanoic placenta. The portion
in contact with the uterine lining is convoluted to increase the surface area in contact with the
uterus but it is not deeply imbedded in the uterine lining. A small amount of uterine milk diffuses
from the uterine tissue to the fetus, but most of the nourishment for the fetus comes from the
yolk sac.
3) The chorioallantoic placenta is more highly vascularized. The fetal and maternal tissues are
more highly interconnected due to the many finger-like projections known as villi that grow into
the uterine lining. Gases and nutrients diffuse from the maternal capillary beds, across the
placental membranes and into the fetal capillaries, and vice versa..

1. How is a chorioallantoic placenta different from a choriovitelline placenta? Give an example of
an animal or group of animals that depend on each.
How is a chorioallantoic placenta different from a choriovitelline placenta? Give an example of
an animal or group of animals that depend on each.

Solution

1) The family Peramelidae/bandicoots has a chorioallantoic placenta. The rest of the marsupials
have a choriovitelline placenta.
2) The choriovitelline placenta is less vascularized than the chorioallanoic placenta. The portion
in contact with the uterine lining is convoluted to increase the surface area in contact with the
uterus but it is not deeply imbedded in the uterine lining. A small amount of uterine milk diffuses
from the uterine tissue to the fetus, but most of the nourishment for the fetus comes from the
yolk sac.
3) The chorioallantoic placenta is more highly vascularized. The fetal and maternal tissues are
more highly interconnected due to the many finger-like projections known as villi that grow into
the uterine lining. Gases and nutrients diffuse from the maternal capillary beds, across the
placental membranes and into the fetal capillaries, and vice versa.