Question

the chorion________. a is the first site of blood cell formation b forms the fetal half of the placenta c becomes the umbilical cord vessels d cushions and protects the embryo with fluid

Explanation:

The chorion is one of the fetal membranes. It contributes to the formation of the placenta. The placenta has a fetal part (chorion frondosum) and a maternal part (decidua basalis).

• Option A: The yolk sac is the first site of blood cell formation, not the chorion.
• Option C: The allantois contributes to the formation of umbilical cord vessels, not the chorion.
• Option D: The amnion cushions and protects the embryo with amniotic fluid, not the chorion.

Answer:

B. forms the fetal half of the placenta