Practice question

Rhizoid morphology serves as reliable diagnostic character distinguishing major bryophyte groups microscopically. Hepatophyta liverworts like Riccia fluitans and Marchantia polymorpha produce unicellular, aseptate smooth rhizoids extending from ventral thallus surface for anchorage and external capillary water absorption via external conduction. Anthoceros hornwort similarly has unicellular rhizoids. In contrast, Bryopsida mosses like Funaria hygrometrica develop multicellular, branched rhizoids with oblique transverse cross walls providing stronger attachment, internal conduction and substrate colonization. Multicellular architecture improves desiccation tolerance and distinguishes mosses phylogenetically. This structural framework illustrates phylogenetic relationships and adaptive significance highlighted in competitive examinations focusing on comparative plant morphology and systematics.