National Geographic: Sizing Up Sperm
Stream the full National Geographic: Sizing Up Sperm movie online for free in crystal-clear HD quality. No downloads required—just press play and enjoy the action, complete with English subtitles for an enhanced viewing experience.
Each of us was the grand prize in an ultimate reality competition, the amazing race a sperm makes on the road to fertilization. Millions of sperm compete while overcoming armies of antibodies, treacherous terrain and impossible odds to reach their single-minded goal. To illustrate the full weight of the challenge, Sizing Up Sperm uses real people to represent 250 million sperm on their marathon quest to be first to reach a single egg.