Fertilization: Beginning a New Organism

Structure of the Gametes

  • Sperm
  • The egg
  • Recognition of egg and sperm

External Fertilization in Sea Urchins

  • Sperm attraction: Action at a distance
  • The acrosome reaction
  • Recognition of the egg’s extracellular coat
  • Fusion of the egg and sperm cell membranes
  • Prevention of polyspermy: One egg, one sperm
  • Activation of egg metabolism in sea urchins
  • Fusion of genetic material in sea urchins

Internal Fertilization in Mammals

  • Getting the gametes into the oviduct: Translocation and capacitation
  • In the vicinity of the oocyte: Hyperactivation, directed sperm migration, and the acrosome reaction
  • Recognition at the zona pellucida
  • Gamete fusion and the prevention of polyspermy
  • Activation of the mammalian egg
  • Fusion of genetic material

Fertilization in Angiosperm Plants

  • Pollination and beyond: The progamic phase
  • Pollen germination and tube elongation
  • Pollen tube navigation
  • Double fertilization