(a) Fertilization :
- Sperm comes in contact and enters the secondary oocyte.
- Activates/induces secondary oocyte to complete meiosis II leads to formation of ovum/ootid.
- The haploid nucleus of sperm and that of ovum fuse to form a diploid zygote completing the process of fertilization.
Implantation:
- Trophoblast layer of blastocyst attaches to the endometrium (of the uterus).
- The uterine cells divide rapidly and cover the blastocyst.
- The blastocyst becomes embedded in the endometrium and the implantation is completed.
- (b) hCG (human chorionic gonadotropin)
- hPL (human placental lactogen)
- estrogen
- progestogens
Detailed answer :
(b) The placenta also acts as an endocrine gland because it produces many hormone-like human Chorionic- Gonadotropin (hCG), human placental Lactogen (hPL), Oestrogen and progesteron and estrogen etc. In the later phase of pregnancy a hormone called as relaxin is also secreled by the ovary, hCG, hPL and relaxin hormone are produced in women only during pregnancy.