Spermatophytes produce male microspores and female megaspores. Male pollen must transfer from anther to stigma, by wind {wind-pollinated flower} or by insect, animal, or bird pollinators {pollinator-pollinated flower}. Wind-pollinated flowers do not have fancy flowers or nectar. Spermatophytes transport pollen down pollen tubes to megaspores and unite gametes {pollination}|, to make fertilized embryos. Seeds have one embryo surrounded by endosperm, surrounded by epidermis. Seeds are transportable units.
Female ovules develop to make eight nuclei, of which two {tube nuclei} form tubes. After pollen grains land on stigmas, ovule and pollen tube nuclei form tubes down through styles to ovules.
Female ovules develop to make eight nuclei, of which three {generative nucleus} participate in fertilization. One generative nucleus divides. Second generative nucleus enters egg nucleus. Female-ovule polar nuclei and third generative nucleus fuse to make endosperm nucleus. Ovule and pollen generative nuclei make embryo {double fertilization}.
Female ovules develop to make eight nuclei, of which two {polar nucleus} become pole markers. Polar nuclei and third generative nucleus fuse to make endosperm nucleus.
Pollination makes fertilized gametes {embryo, plant}.
Ovule polar nuclei and third generative nucleus combine to make a nucleus {endosperm nucleus}.
Seeds have nutrient layers {endosperm} that surround embryos and have epidermis coverings. Endosperm nucleus makes endosperm.
4-Botany-Plant-Vascular-Angiosperm
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Date Modified: 2022.0225