The heterosporous pteridophyte show certain characteristics, which are precursor to the seed habit in gymnosperms. Explain

Explanation

Heterospory is present in Selaginella ( a pteridophyte ). Microspores produce male gametophytes and megaspores produce female gametophytes - Male gametophyte leads to formation of male gametes. Female gametophyte forms archegonia in which female gamete egg is present . It also porvides food to the developing embryo .
Thus it finally leads to reduction of gametophyte in situ germination of seeds and retention of female gametophyte in megasporangium thereby taking part in seed formation in gymnosperms.