(a) (i) Ovary: It produces egg for fertilisation. It secretes estrogen and progesterone. Estrogen regulates secondary sexual characters and progesterone controls the thickness of the lining of uterus.
(ii) Oviduct : It is the site of fertilization and carries egg or fertilized ovum (zygote) to the uterus.
(iii) Uterus : It helps to nourish the fertilised ovum that will develop into foetus. It holds the baby till it is ready for birth.
(b) Placenta is a disc shaped structure on uterine wall before implantation of embryo. It provides oxygen and nutrients to the foetus.It helps to remove waste also. The placenta is composed of both material tissues and tissue derived from the embryo. The chorion is the embryonic derived portion of the placenta. It is composed of fetal blood vessels and trophoblasts which are organized into finger-like structures called chorionic villi.