Seed dispersal

1. Seed Dispersal 8SCIENCE Thurs. March 24, 2011

2. Review: Seed Plants What are the two types of seed plants? Gymnosperms Angiosperms What is the difference? Gymnosperms have cones Angiosperms rely on pollination Today we will learn about how seeds formed in gymnosperms or angiosperms are dispersed (spread)

3. Seed Dispersal Seeds need to get from where they are formed to the ground to grow into a new plant How do seeds get to the ground? Gravity What abiotic/biotic factors help to spread seeds? Animals Water Wind

4. Animal dispersal Some seeds are eaten in fruits and dispersed as animals move around ‘Hitchhiking’ Attaching to animal fur/skin/clothing can help to disperse seeds Ex: apple seeds, burs

5. Water dispersal Rain may cause seeds to fall out of a fruit or cone Rivers/oceans may carry seeds to new locations Some seeds float Ex: Coconut palm seed

6. Wind dispersal Some seeds have special structures that allow them to be carried by the wind If seeds are very small they may be carried far on the wind Ex. Dandelion seeds

7. How does the seed structure relate to how it is dispersed?