Transcript Plant Structures for Defense

Plant Structures for
Defense
Plants have special
structures that function for
defense, survival, and
reproduction.
Structures for defense protect
plants from threats. They
might die without these
defenses.
Thorns
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Are sharp outgrowths on the stems of
plants
Defend the plant from being eaten by
some animals
Cactus
Poisons
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Some plants have chemical substances
designed to discourage animals from eating
them.
Some taste bad; some sicken or kill the
predator.
Some have high poison levels only until the
fruit matures, then it decreases so the fruit
can be eaten and seeds dispersed.
Ex. Poison ivy, poison oak, sumac
Poison Ivy
Other Defense
The ability to close its leaves
when touched is called
(thigmotropism).