Examine this close-up of the placenta (on the left of the figure below).
Why do the chorionic villi have the shape of a tree?
A)The branches of the chorionic villi create a large amount of surface area for the exchange of nutrients and gases between maternal and fetal blood.
B)The branches of the chorionic villi allow blood to flow back and forth more rapidly between the capillaries of the mother and her fetus.
C)The branches of the chorionic villi create more locations where fetal capillaries can fuse directly with maternal capillaries.
D)The branches of the chorionic villi create more surface area for the production of the amniotic fluid.

Question

Examine this close-up of the placenta (on the left of the figure below). 
Why do the chorionic villi have the shape of a tree?
A)The branches of the chorionic villi create a large amount of surface area for the exchange of nutrients and gases between maternal and fetal blood. 
B)The branches of the chorionic villi allow blood to flow back and forth more rapidly between the capillaries of the mother and her fetus. 
C)The branches of the chorionic villi create more locations where fetal capillaries can fuse directly with maternal capillaries. 
D)The branches of the chorionic villi create more surface area for the production of the amniotic fluid.

Quizplus · Accepted Answer

The branches of the chorionic villi create a large amount of surface area for the exchange of nutrients and gases between maternal and fetal blood. This allows for efficient transfer of oxygen and nutrients from the mother to the fetus, and carbon dioxide and waste products from the fetus to the mother. The tree-like shape of the chorionic villi allows for maximum surface area within the limited space of the uterus.

Examine This Close-Up of the Placenta (On the Left of the Figure