1) Water moves up through the xylem tissue in plants through a process called capillary action. Capillary action is driven by the forces of cohesion between water molecules and adhesion of water to the xylem walls. 2) Transpiration is the evaporation of water from the leaves of plants through pores called stomata. It creates an upward pull that drives the movement of water through the xylem. 3) Deforestation reduces the amount of water released into the atmosphere through transpiration, which can impact worldwide weather patterns.

1. © 2004 Plano ISD, Plano, TX

2. © 2004 Plano ISD, Plano, TX
WaterWater
is necessary for plant survival.
O
HH HH
2

3. © 2004 Plano ISD, Plano, TX
moves from soil through roots
contains mineral nutrients
necessary for plants to thrive
O
HH HH
3

4. © 2004 Plano ISD, Plano, TX
continues in a
continuous column
evaporates
through stomata
roots  stem
stem  leaf
O
HH HH
4

5. © 2004 Plano ISD, Plano, TX
evaporates
through stomata
roots  stem
stem  leaf
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HH HH
5

6. © 2004 Plano ISD, Plano, TX 6
stomata

7. © 2004 Plano ISD, Plano, TX
The evaporation of water from
leaves through the stomates is
transpiration.
7

8. © 2004 Plano ISD, Plano, TX
How is transpiration
affected by
deforestation in the
tropical rainforests?

9. © 2004 Plano ISD, Plano, TX
Where the tropical rain forests of
the world are concerned, clearing 27
million acres/year to create grazing
land for cattle has a serious impact
on the worldwide weather pattern.
Therefore, when these plants are
removed, the amount of water they
release to the atmosphere is also
removed.

10. © 2004 Plano ISD, Plano, TX
Water moves
up a
continuous
column of
hollow cells
called
Xylem tissue runs
continuously from
roots  stems 
leaves.
xylem.
xylem
xylemxylemxylem
10

11. © 2004 Plano ISD, Plano, TX
Cohesion and adhesion
are two of several factors that
help regulate the movement of
water through a plant.
11

12. © 2004 Plano ISD, Plano, TX
O
HH HH
+ +
_
Because a water
molecule is polar, it
can attract like and
unlike molecules.
O
HH HH
+ +
_
O
HHHH++
_
O
HH
HH +
+
_
O
HH
HH
+
+
_
O
HH
HH
+
+
_
Water sticking to
water is cohesion,
the attraction of
like molecules to
each other.
cohesion, the
attraction of like
molecules to each
other.
12

13. © 2004 Plano ISD, Plano, TX 13
The strong attraction water
molecules have to each other
(cohesion) and to the walls of
xylem tubes (adhesion) results in
a process called
capillary action.

14. © 2004 Plano ISD, Plano, TX
Capillary action and
transpiration are two of the
processes needed to keep
water moving through a
plant.
14

15. © 2004 Plano ISD, Plano, TX

16. © 2004 Plano ISD, Plano, TX
What will happen when one end of a dry
string is put in a beaker with water and
the other end is put in an empty beaker?
Water sticking to water is _______.
Water sticking to string is _______.
cohesion
adhesion
16

17. © 2004 Plano ISD, Plano, TX
Identify this process.What is the purpose of this process?
17

18. © 2004 Plano ISD, Plano, TX
xylemxylemxylem
What two forces are
involved in this process?
What is this process called?
18

19. © 2004 Plano ISD, Plano, TX
Bibliography
Gibson, Matthew. ( ____ ). Transportation in plants.
http://www.iit.edu/~smile/bi9703.html
Water ya know about dat? (1996 ). Water Lesson. Utah State Office of Education: Salt
Lake City. [Online]. Available:http://www.wested.org/werc/earthsystems/water/wateryah
know.html
Kotz, John C. and Purcell, Keith F. (1991). Chemistry and chemical reactivity.
Ft. Worth, Texas: Harcourt Brace Jovanovich College Publishers.
Transpiration in Plants (1996 ). Rain Forest Teaching Module. Rain Bird Sprinkler Mfg. Corp:
[Online]. Available: http://www.rainbird.com/rainforest/9-12_transpiration.htm