(N/A) Diagram: Refer to the sectional view of the human female reproductive system in the textbook.
Labels:
$(i)$ Ovary: The site where eggs (ova) develop.
$(ii)$ Fallopian tube (Oviduct): The site where fertilization takes place.
$(iii)$ Uterus: The site where the fertilized egg (embryo) gets implanted.
$(b)$ $(i)$ To receive the zygote,the inner lining of the uterus (endometrium) becomes thick,soft,and richly supplied with blood vessels to nourish the developing embryo.
$(ii)$ If the zygote is not formed,the thickened uterine lining is no longer needed. It breaks down and is shed along with blood and mucus through the vagina,a process known as menstruation.