Gymnosperms For the lower vascular plants the important evolutionary development was in the water and food conducting tissues of the sporophyte. As we move on through the plant kingdom the next important development was the seed. The free living gametophyte is a vulnerable phase of the life cycle. Reproduction by seeds is a less chancy procedure and has other advantages for plant survival and dispersal. Seeds can be remarkably tolerant of environmental extremes heat, cold …showed first 75 words of 2068 total…

…showed last 75 words of 2068 total…most forest or woodland ecosystems. Cycads are often abundant as understorey species and they fix nitrogen which is an important addition of nitrogen fertilizer for nutrient cycling. resources: 1 http://www.hcs.ohio-state.edu/hcs300/gymno.htm 2 Biology, Dynamics of Life pages 610-612 3http://www.sbs.auckland.ac.nz/student_information/biology_web_pages/nzplants/gymnosperm_intro.htm 4 http://generalhorticulture.tamu.edu/lectsupl/print/page04.html 5 http://helios.bto.ed.ac.uk/bto/microbes/mycorrh.htm