After fertilization, the zygote remains in the archegonium and divides by mitosis repeatedly to form a multicellular, diploid embryo, the young sporophyte. Sugars and other materials are translocated from gametophyte to the developing sporophyte through placental tissue, a type of nutrition called matrotrophy. (No plasmodesmata connect the gametophyte and sporophyte; movement of material is along the cell wall, that is, it is apoplastic movement ). The sterile jacket cells also divide and in mosses form a tight cap, the calyptra, over the tip of the developing sporophyte. The mature sporophyte in both liverworts and mosses consists of a foot, seta, and capsule. The moss capsule has modifications to assist in spore release: a cap, the operculum, covers the opening, and peristome teeth form a ring around the mouth of the capsule. Sterile cells, elaters, within
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This note was uploaded on 11/14/2011 for the course BIO 1421 taught by Professor Farr during the Fall '08 term at Texas State.