Flexi Says: After wind (initially) carries the male gametophyte/pollen to the female gametophyte, the pollen germinates, growing a tube (often through that convenient micropyle) into the ovule. The pollen tube allows sperm or sperm nuclei to enter the ovule and fertilize the egg, forming the zygote. The ovule then develops into a seed (Figure below), with three basic parts:
The zygote divides and differentiates, forming the embryo – a young plant (sporophyte) of the next generation. While still within the seed, the embryo develops a primordial leaf (the cotyledon), stem (the hypocotyl = “beneath the cotyledons”), and root (the radicle).
Stored food to nourish the seed in its eventual home develops from maternal or gametophyte tissue.
The ovule integument becomes the protective seed coat.
