Question

Placenta in humans is a temporary organ formed during pregnancy. It is formed by

• A. chorion and uterine wall
• B. chorion only
• C. amnion only
• D. yolk sac only

Answer 1

The correct option is A chorion and uterine wall

Placenta in humans is formed by a combination of chorion (fetal tissue) and the uterine wall (maternal tissue). The outer layer of blastocyst called the trophoblast is involved in the formation of chorion. The chorion becomes intimately associated with the endometrial lining of the uterus and together they form the placenta. The placenta is a structure which contains both the maternal and fetal tissues.
Amnion is the membrane that surrounds the amniotic cavity that forms during the process of gastrulation between the cells of epiblast. Within the amniotic cavity, the amniotic fluid is found, which acts as a shock absorber for the embryo.
Yolk sac is formed by the hypoblast cells. It serves as a site of formation of blood cells in the early embryo. The yolk sac also contributes to the formation of the umbilical cord