Anthers  on  stamens  ->  (meiosis) 4 haploid microspores -> (mitosis)
   pollen grain with 2 sperm + tube cell
   Ovaries  in  pistils  ->  (meiosis)  1  haploid megaspore -> (mitosis)
   embryo sac with 8 nuclei.

   Pollination  occurs  when  pollen  grains make contact with the stigma
   (silks)  and develop pollen tubes that grow toward the embryo sac. One
   sperm  unites  with  the  oocyte nucleus and the other unites with two
   endosperm nuclei.
   This  double  fertilization  produces  a  diploid zygote nucleus and a
   triploid endosperm nucleus.