Gymnosperms And Angiosperms: General Characters of Gymnosperms: The ‘Gymno’ means naked and ‘Sperm’ means seeds. So, Gymnosperms are seed plants without flowers. These are heterosporous i.e. produce two types of spores, the microspores and megaspores. The microspores develop into male gametophyte and the megaspores develop into the female gametophyte. The main plant is a diploid