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Explore how seeds disperse and germinate under diverse conditions like through animals, wind, and water, uncovering the stages of growth from embryo to seedling. Learn about seed dormancy, germination phases, and the birth of seedlings.
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KEY CONCEPTSeeds disperse and begin to grow when conditions are favorable.
Animals, wind, and water can spread seeds. • Seeds dispersed by animals can have nutritious fruits or fruits that cling.
Cypselae Double samaras • Seeds dispersed by wind can have wing- or parachute-like fruits.
Seed dormancy is a state in which the embryo has stopped growing. Seeds begin to grow when environmental conditions are favorable. • Dormancy may end when conditions are favorable. • While dormant, embryo can withstand extreme conditions.
Germination begins the growth of an embryo into a seedling. • water causes seed to swell and crack coat • embryonic root, radicle, is first to emerge • water activates enzymes that help send sugars to embryo
Germination begins the growth of an embryo into a seedling. water causes seed to swell and crack coat embryonic root, radicle, is first to emerge water activates enzymes that help send sugars to embryo • embryonic shoot, plumule, emerges next
Germination begins the growth of an embryo into a seedling. water causes seed to swell and crack coat embryonic root, radicle, is first to emerge water activates enzymes that help send sugars to embryo embryonic shoot, plumule, emerges next • leaves emerge last