embryo development

Question 1

what cells of the embryo form the placenta

Answer 1

throphoblasts

Question 2

by what week is the foetal heart and placenta functional by>

Answer 2

5th week

Question 3

what role does progesterone play in placental development

Answer 3

it stimulates the decidual cells to concentrate glycogen, protein and lipids

Question 4

what cells secret hcg

Answer 4

syncitiotrophoblasts