12 most iconic rivers on Earth. The Yangtze River's most famous sites include the incredible Three Gorges and the gargantuan Three Gorges Dam. There's a reason you know the names of these rivers--the Nile, the Mississippi, the Amazon--they've inspired exploration, legend, religion. Discover the waterways that shaped the world--and the cruises that reveal their secrets.
Illustration depicting ovulation and fertilization. Human fertilization is the union of a human egg and sperm, usually occurring in the ampulla of the uterine tube. The result of this union is the production of a zygote cell, or fertilized egg, initiating prenatal development.Scientists discovered the dynamics of human fertilization in the nineteenth century.The process of fertilization involves a sperm fusing with an ovum.he result of this union is the production of a zygote cell, or fertilized egg, initiating prenatal development. Scientists discovered the dynamics of human fertilization in the nineteenth century. The process of fertilization involves a sperm fusing with an ovum.
In order for implantation to take place, ovulation and fertilization must occur first. Implantation happens early in the pregnancy stage after the fertilized egg (zygote) travels down the fallopian tube to the uterus and adheres to the epithelium, or uterine lining. It takes about eight to 10 days for the fertilized egg to travel to the uterus.