Seeds by shuifanglj

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									What Adaptations Do Plants
 Have to Disperse Seeds?
Plants rely on their environment
to disperse seeds.
• Wind
• Animal Transport
  External
  Internal
  Other: burying seeds
• Drop to ground
                 Wind Dispersal
Some structures allow seeds to be easily carried in
the wind.




                         Achene           Pappus
Some plants depend upon animals to disperse their
seeds. There are three variations of animal
dispersal:
    •External Transport
       Examples of seed structures for external
       transport:
           •Hooks
           •Barbs
    •Internal Transport
       •Seeds are encased in fleshy fruits
    •Inadvertent dispersal (burying seeds)
Projections extending from a seed case attach onto a
passing animal, carrying the seed to a new location.
Barbs attach to animal fur.


                              Barb
Fleshy fruits surround seeds to be consumed and
expelled by animals.
The Oak tree depends upon the squirrel for its
seed dispersal.




Squirrels bury acorns in the Fall and often forget where
they are in the winter. These seeds then sprout new trees.
Some plants simply drop the seeds on the ground.




 Individual seed
What are some disadvantages of this method?
    What adaptations do seeds have to assist
    in dispersal?
    Identify the adaptation and type of dispersal
    for each of the following pictures.




1                    2                   3




        4                    5
                          Answers


1                                   3
    Acorn: Food; animal dispersal   Composite: Pappus; wind




    2                               4
                                     Wildflower: Drop dispersal
    Wildflower: Hooks;
    animal dispersal

                                         Composite: Pappus; wind
                     5
This is an individual seed case from the burdock bur taken
at 60X.




Seed photos in this presentation were taken with the QX3 Intel Play
Microscope.

								
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