Pregnancy physiology: fertilization & zygote

The duration of pregnancy in human beings is around 280 days.
FERTILIZATION:-

fertilization is a process of union of male and female gametes to form zygote. This generally occurs at the outer end of the fallopian tube. After the sexual act, sperms travel towards the uterus and enter the fallopian tube . the ova released from the mature griffin follicle is taken up by the fimbrial end of fallopian tube. Ova meet the sperms in the fallopian tube. A single sperm enters the ova to fertilize it. Ovum survives in the genital tract for 24hours and the sperm for 72 hours.

ZYGOTE:-
The fertilized ovum is called zygote.  Zygote has 46 chromosomes. It undergoes repeated division and forms a morula.  Morula moves through the tube and gets implanted in the cavity of he uterus. The morula touches the endometrium of the uterus to form a blastocyst by about 5Th day after fertilization.