• The stamen is the male reproductive organ of the plant. It is composed of the anthers and filament. The anthers are what give off the sperm (pollen). They are held and located at the tip of the filament.
  • The pistil (aka carpel) is the female reproduction organ of the plant. It is composed of the stigma, style, and ovary. The stigma is what catches the sperm (pollen). It travels down the style which directs it to the ovary. The ovary then releases the pollen to the ovule which it contains, which then initiates gametic fusion (eggs are stored in the ovule) and the creation of a seed.
  • The petal is what attracts carriers of pollen to the flower to make the "exchange" parsay (pollen for nectar for example). 
  • Sepals (which would be between the petals in the picture) surround the petals and act as protection for the plant. They protect the plant while the flowers are in a bud state and when the flower is mature it protects from insect attack or poison.
  • Double fertilization is when a sperm combines with both the egg and cell in the plant. Pollen grain has two sperm and one combines with the egg to make a zygote and the other combines with two nuclei to form the endosperm. The endosperm is the embryo's food supply and is usually composed of starch.



picture from here