Sporophyte

• The sporophyte generation begins as a zygote formed by an egg and sperm cell fused during sexual reproduction. In most species, the sporophyte generation is the familiar and predominant part of the plant. A cactus, pine tree and fern frond all represent the sporophyte generation.
  
  

Gametophyte

• When the sporophyte produces a spore with a half-set of chromosomes, that spore gives rise to the gametophyte generation. In most plants, the gametophyte generation is more difficult to observe. The gametophyte generation in flowers consists of pollen and reproductive structures; it is the major stage in the life of mosses and an independent plant in ferns.
  
  

History

• The club-topped moss structures are the sporophyte generation, dependent on the gametophyte generation to survive.moss image by Alison Bowden from Fotolia.com
  
  In later-evolved plants, the sporophyte generation dominates, and the gametophyte is small and dependent on the sporophyte for survival. This was not always the case, and the gametophyte generation dominated in early plants, such as mosses. The shift toward sporophyte dominance is a theme found throughout plant evolution.