AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |
Back to Blog
It is often stated that alternation of generations refers to both the diploid and haploid stages being "multicellular" and this is more important than "free-living". The distinction of "free-living" is important, because all sexually reproducing organisms can be thought to involve alternating phases, at least at the cellular level as meiosis. This cycle, from gametophyte to gametophyte, is the way in which plants and many algae undergo sexual reproduction. This sporophyte produces spores by meiosis, which germinate and develop into a gametophyte of the next generation. Two gametes (originating from different organisms of the same species or from the same organism) combine to produce a zygote, which develops into a diploid plant of the sporophyte generation. The life cycle of organisms with "alternation of generations" is characterized by each phase consisting of one of two separate, free-living organisms: a gametophyte ( thallus (tissue) or plant), which is genetically haploid, and a sporophyte (thallus or plant), which is genetically diploid.Ī haploid plant of the gametophyte generation produces gametes by mitosis. A more understandable name would be "alternation of phases of a single generation" because we usually consider a generation of a species to encompass one complete life cycle. The term is a bit confusing for people familiar only with the life cycle of a typical animal. The gametophyte produces haploid gametes which fuse to form a diploid zygotic sporophyte.Īlternation of generations is a reproductive cycle of certain vascular plants, fungi, and protists. Haploid cells undergo mitosis to produce a gametophyte. ![]() A diploid (2n) sporophyte undergoes meiosis to produce haploid (1n) reproductive cells, often called spores.
0 Comments
Read More
Leave a Reply. |