These are the last two questions I found.
Why is the placenta unique as to its origin?
A it's the first fetal structure to develop
B it's allows the mixing of oxygen and nutrients between mother and child
C its develops from material supplied both by the mother and the fetus
D it provides the fluid that surrounds and protects the embryo
i believe the correct answer is D
which of the following hormones is present in a woman's bloodstream right before she gives birth?
C amniotic fluids
i believe the correct is D but i'm not sure
I believe they are both correct. This site may help clarify your last question.
The amniotic sac provides the fluid that protects the embryo. The placenta allows the transfer of materials between the mother and child. It develops well before the fetal stage of development, and develops from the blastocyst (zygote), but not the mother. B is the best answer.
Both oxytoxin (provided by the fetus) and prostaglandins (from the placenta) are produced during labor. Thus I would go with either a or D.
I checked this information in Strong and DeVault's "Human Sexuality" (1994).
I hope this helps a little more. Thanks for asking.