Fill in the blanks and choose the correct options given below.

(i) is the process in which blastocyst become embedded in endometrium of the uterus and leads to pregnancy.

(ii) After implantation, finger-like projections appear on the trophoblast called which are surrounded by the uterine tissue and maternal blood.

(iii) facilitates the supply of oxygen and nutrients and removal of CO 2 and excretory material produced by embryo. It is connected through
to the embryo

(iv) Placenta acts as endocrine tissue as it produces hormones like , hPL, , progestogens, etc.

(v) In later phase of pregnancy, a hormone called is also secreted by ovary.

(vi) After implantation, the inner cell mass differentiates into an outer layer , inner layer and middle layer .

(vii) The inner cell mass contains cetain cells called cells which have the potency to give rise to all the tissues and organs.

(viii) By the end of month, foetus develops limbs and digit and by end of trimester, most of major organ systems are formed.

(ix) The first movement of the foetus and the appearance of hair on the head are usually observed during month of pregnancy.

(x) The average duration of human pregnancy is about months which is called period.

(xi) Parturition is induced by a complex mechanism. The signals for parturition originate from and which induces mild uterine contraction called reflex.

(xii) hormne acts on the uterine muscle and causes stronger uterine contraction.

(xiii) The milk produced during the initial few days of lactation is called .