Tropisms
To turn toward or
away from a
stimulus.
Toward is positive
Away is negative
http://education-portal.com/academy/lesson/tropisms-phototropic-geotropic-and-thigmotropic-plantgrowth.html
http://www.youtube.com/watch?v=pCFstSMvAMI
Geotropism (Gravitropism)
 Plant
growth toward or away from Earth
or (gravity).


Roots grow down for anchorage
http://www.youtube.com/watch?v=mYZXax8V_L0
Chemotropisms
 Plant
growth toward or away from
chemicals.

Roots grow toward useful minerals and
grow away from harmful minerals.
Phototropism
 Plant
light.
growth toward or away from the
phototropism experiment
https://drive.google.com/a/g.dentonisd.org/file/d/0B1XNUrs2mu16dGdPVWJmNGNXO
DQ/view
https://www.youtube.com/watch?v=zctM_TWg5Ik
HD: computer enhanced
https://www.youtube.com/watch?v=g8mr0R3ibPU
Thermotropism
 Plant
response due to heat.
Thigmotropism
 Plant
growth and movement in response
to touch.


Vines will use thigmotropism to grab on for
support to carry out phototropism in search
for light.
Mimosa plants respond to touch for
protection.

http://www.youtube.com/watch?v=m2xKjA69jNM

https://www.youtube.com/watch?v=hG2olNnCi4U
Hydrotropism
 Plant
growth toward water.
Hydrotropism
 Necessary
for
TURGOR PRESSURE –
water pressure inside
plant cells that allow
the plant to stand
tall.
Tropism review
 https://www.youtube.com/watch?v=zctM
_TWg5Ik
 http://www.youtube.com/watch?v=eDA8
rmUP5ZM
Xylem
Vessels in a plant that bring water
and nutrients up the stem of a
plant and to the leaves.
http://study.com/academy/lesson/xylem-the-effectof-transpiration-and-cohesion-on-function.html

https://www.youtube.com/watch?v=Ir9bm3fli90