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.
If the pollen lands near the ovary, a pollen tube will form which has two. sperm nuclei. Once the tube reaches the ovule, one sperm will fertilize the ovule and the other breaks apart as it is not needed. More than one pollen may be growing a pollen tube to the same ovule but only one embryo will be formed. embryo will develop into a seed. This seed can then leave the cone and be blown away in the wind.