asexual gemmae within gemma cup on thallus of liverwort (marchantiophyta), scotland - 單元體 個影片檔及 b 捲影像00:13
evolution of vascular plants: the ferns - part 21 of 28. describes the evolution of vascular systems in land plants. the highly specialized structures that occur in vascular plants are shown through investigation of the fern. explains the adaptive advanta - 單元體 個影片檔及 b 捲影像00:30