When embryo develops in the body of female but it does not obtain netrients from the mother

How does Embryo get nourishment inside the mother's body?

How does growing embryo get nutrition from the mother's blood ?

(a) When and how does placenta develop in human female? (b) How is the placenta connected to the embryo? (c) Placenta acts as an endocrine gland. Explain.

(a) When and how does placenta develop in human female? (b) How is the placenta connected to the embryo? (c ) Placenta acts as an endocrine gland. Explain.

In case of polyembryony, an embryo A develops from the synergids and the embryo B develops from the nucellus. State the ploidy of embryo A and B.

In case of polyembryony, an embryo A develops from the synergids and the embryo B develops from the nucellus. State the ploidy of embryo A and B.