alternation of generation

• Alternation of generation is the reproductive cycle of plants.
• Haploid phase (1n) is gametophyte.
• Diploid phase (2n) is sporophyte.
• Sporophyte stage is not visible while gametophyte stage is dominant in mosses and other non vascular plants
• Gametophyte stage is not visible while sporophyte stage is dominant in ferns and other seedless vascular plants.
• Sporophyte stage is dominant and gametophyte stage is reduced in seed plants (gymnosperms and angiosperms).
• Alternation of generation process:

  
  

  Gametes - zygote - sporophyte - meiosis - haploid spores - germinate - new gametophytes
• Green algae and bryophytes

  1. Dominant phase of the life cycle is the gametophyte stage
  2. Haploid, gives rise to gametes by mitotic divisions
  3. Haploid gametes fuse at fertilization and produce a zygote (2n)
• Ferns and fern allies, as well as seed plants

  1. Possess a dominant sporophyte (diploid) generation
  2. Initially dependent on gametophyte for nutrition; eventually becomes independent
  3. Gametophyte is reduced
• Ferns: saprophytic or autotrophic

  Seed plants: parasitic on the sporophyte
• Meiosis produces haploid spores while mitosis produces gametes in plants.
• In meiosis, chromosome reduction results in the formation of haploid cells that now are a part of the gametophyte generation.
• Sporic life cycle is the type of plants' life cycle.
• The products of meiosis are spores.
• Seta holds the capsule.
• Stipe holds the leaves or pinna.
• Sori is the black spots in ferns.