-A prothallium rarely fertilizes itself because the antheridia and archegonia mature at different times-Globe-shaped antheridia from first, followed by archegonia. -Archegonia are vase-shaped and are located near the cleft of the prothallium-After producing sperm, antheridia drop off, leaving sperm to swim to the archegonia of the other prothallia.
Biology 1106 Exam 2. STUDY. both occur on the underside of the prothallium but the prothallium rarely fertilizes itself because the antheridia and archegonia mature at different times. through the soil. homosporous. produce one kind of spore that develops into a single kind of gametophyte that produces both antheridia and archegonia.
The archegonia and antheridia mature at different times to avoid self-fertilization. = 2n (diploid) = n (haploid) Antheridia (male) Archegonia (female) Rhizoids (roots) GAMETOPHYTE New Sporophyte sorus SPOROPHYTE SPORANGIUM When the haploid spores are ready, they released ferns produce only one type of spore (they are homosporus). MEIOSIS.
Archegonia and antheridia mature at different rates to prevent intragametophytic selfing. One of the most interesting strategies used by ferns to prevent evolutionary stagnancy is polyploidy. Over 95% of ferns have been found to be polyploid (Haufler, 2002). This results from a .