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Learning Target: Seed Dispersal 02/24. I Can … Describe different ways that seeds can be dispersed and compare/contrast the advantages/disadvantages of the different methods. I Will … Define seed dispersal List methods of seed dispersal including examples of plants for each method
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Learning Target: Seed Dispersal 02/24 I Can… Describe different ways that seeds can be dispersed and compare/contrast the advantages/disadvantages of the different methods • I Will… • Define seed dispersal • List methods of seed dispersal including examples of plants for each method • Discuss advantages/disadvantages of each method
Seed Dispersal Dispersal (the process or result of the spreading of organisms from one place to another) is important because: It spreads the progeny (offspring) in order to colonize new environments Reduces competition for resources with parents Reduces chances of predators destroying all of the plant’s yearly seed production
Self Dispersal • Plants disperse their seeds by forceful ejection • Explosive fruits • Witch Hazel • Squirting Cucumber http://youtu.be/q5g7EV2fgJw
Self Dispersal The peanut plant sows (buries) it own seeds
Wind Dispersal • Fruit and seeds may have special devices for wind dispersal • Plumes catch wind currents • Dandelion • Trees take advantage of their great heights for wind dispersal • Fruits with wings are used to slow descent to land • Maple • Ash
Fruits and/or seeds use flotation devices to travel by water ( in rivers, oceans, etc…) • Fruit may have air spaces and corky floats • Palm Coconuts Water Dispersal
Water Dispersal • Lotus Flower
Animal Dispersal • Many plants depend on animals for seed dispersal • Offers nutritional reward • Animals learn to recognize ripened fruit colors • Fleshy fruit eaten and seeds dispersed in feces
Animal Dispersal • Some dry fruit attach and cling to animal’s fur (e.g. Beggar’s ticks) • Some have Velcro-like hooks that cling to fur (Burdock, Cockleburs) • Others have sticky substances that adhere to host (e.g. Mistletoe)
Methods of Seed Dispersal Seed Dispersal Time: 4 mins17 secs http://youtu.be/6loGKPKDqCw How Plants Disperse Seeds Time: 3 mins 30 secs http://youtu.be/rhp5k5ptSx0?t=23s
Seed Dispersal: Things that make you THINK • What carries the dandelion seed for miles? • What feature of trees gives them a particular advantage when dispersing seeds by air? • How does the squirting cucumber disperse its seeds? • What is the advantage of this? • Although plants use wind and water, what do most plants use as carriers for their seeds? • Blackberries on a tree do not ripen simultaneously, WHY?