22 3 Seed Dispersal and Germination KEY CONCEPT
- Slides: 9
22. 3 Seed Dispersal and Germination KEY CONCEPT Seeds disperse and begin to grow when conditions are favorable.
22. 3 Seed Dispersal and Germination Animals, wind, and water can spread seeds. • Seeds dispersed by animals can have nutritious fruits or fruits that cling.
22. 3 Seed Dispersal and Germination • Seeds dispersed by wind can have wing- or parachutelike fruits. Cypselae Double samaras
22. 3 Seed Dispersal and Germination • Seeds dispersed by water can have fruits that float.
22. 3 Seed Dispersal and Germination Seeds begin to grow when environmental conditions are favorable. • Seed dormancy is a state in which the embryo has stopped growing. – Dormancy may end when conditions are favorable. – While dormant, embryo can withstand extreme conditions.
22. 3 Seed Dispersal and Germination • 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
22. 3 Seed Dispersal and Germination • 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
22. 3 Seed Dispersal and Germination • 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
22. 3 Seed Dispersal and Germination • Once photosynthesis begins, the plant is called a seedling.
