Introduction: Fertilization
Fertilization is the process by which sex cells unite to form a zygote, or fertilized egg. Fertilization results in a new cell with a unique mix of genes. Sex cells (sperm or eggs) contain half the number of chromosomes normally found in the cells of an organism. Fertilization results in a complete set of chromosomes.
Still Image:
Sea urchin sperm
Sperm from the sea urchin, Lytechinus pictus.
Sea urchin sperm was diluted in seawater, then mounted between a slide and coverslip. This image was taken on an inverted compound microscope with a 40x DIC objective and digital camera.