Flowering plants Sexual reproduction

flowers sexual organs of flowering plants.

flowering plants dominant plant form on land , reproduce either sexually or asexually. distinguishing feature reproductive organs, commonly called flowers. anther produces pollen grains contain male gametophytes (sperm). pollination occur, pollen grains must attach stigma of female reproductive structure (carpel), female gametophytes (ovules) located inside ovary. after pollen tube grows through carpel s style, sex cell nuclei pollen grain migrate ovule fertilize egg cell , endosperm nuclei within female gametophyte in process termed double fertilization. resulting zygote develops embryo, while triploid endosperm (one sperm cell plus 2 female cells) , female tissues of ovule give rise surrounding tissues in developing seed. ovary, produced female gametophyte(s), grows fruit, surrounds seed(s). plants may either self-pollinate or cross-pollinate.

nonflowering plants ferns, moss , liverworts use other means of sexual reproduction.

in 2013, flowers dating cretaceous (100 million years before present) found encased in amber, oldest evidence of sexual reproduction in flowering plant. microscopic images showed tubes growing out of pollen , penetrating flower s stigma. pollen sticky, suggesting carried insects.