learning objective to understand the different ways in which plants disperse their...
TRANSCRIPT
Learning Objective
To understand the different ways in which plants disperse
their seeds.
What does seed dispersal mean?
Seed dispersal is when seeds are transported from the plant to another area in order to grow.
What do you think plants decide to spread their seeds out over a
wider area?
If a mother plant and a baby plant are in the same place they will compete for water, sunlight and carbon dioxide. The baby plant is much weaker
and therefore will in most cases not receive enough and die.
Can you think of any ways in which seeds might travel
from one place to another?
We call these methods of seed dispersal.
Animal dispersal by hooked fruits
Some species of plant use hooks on their fruits.
These attach themselves to the fur of mammals or feathers of birds and get carried from one place to
another.
Acorns fall from the tree and
sprout
Acorns fall from trees and roll.
If they are not destroyed by animals, white oak acorns can sprout rapidly after
falling from the tree.
Animal burial
Hard nuts are usually destroyed if chewed or eaten. However,
animals such as squirrels may store
them to eat later and forget to go back to
get them, giving them a chance to germinate.
On rare occasions, birds such as blue jays can transport acorns
long distances.
Soft fruit dispersal
Fleshy fruits are eaten by animals.
The seeds are then dispersed after
passing through the digestive system of animals that have eaten the fleshy
fruits.
Wind dispersal
Some plants, such as the dandelion, have seeds that act as parachutes, which are carried away by the
wind.
Spinning dispersal
Maple fruits are winged, two-seeded pods. They spin like helicopters as they fall from the tree,
providing a longer time for dispersal by wind.
Plantlet reproduction
Spider plants, amongst others, send out stems which produce
plantlets, these baby plants then try to root themselves.
Carried by water
Some plants grow near rivers, lakes, streams or oceans.
Their fruits/seeds fall from the plant
and are carried away by the water.
Exploding Plants
Spider plants, amongst others, send out stems which produce
plantlets, these baby plants then
try to root themselves.