Double+Fertilization


 * 1) Pollen grain lands on the stigma.
 * 2) Pollen tube begins to grow downward.
 * 3) the tube nucleus leads the way.
 * 4) other nucleus divide to form 2 sperm nuclei.
 * 5) Pollen tube grows down the style until it reaches the micropyle( small opening to the ovary).
 * 6) Double fertilization occurs: one sperm nucleus unites with egg to form the zygote; the other unites with the two polar nuclei to form a triploid endosperm.
 * 7) Endosperm= food storing cells.
 * 8) Embryo is protected by a seed coat.