Describe the process of double fertilization in flowering plants.

Pollination takes place. Growing, one cell forms a pollen tube, which grows, moving towards the column and ovary, two sperm are formed from the other cell. When the pollen tube penetrates into the embryo sac, the nucleus divides three times by mitosis, two haploid nuclei merge in the center, the rest of the eggs near the pollen duct. One of the sperm fuses with the central egg, the other with the egg at the entrance.