Download 3.Stomata Condensation by Plants

Stomata Condensation by
Plants
Presentation by:
 Ladan Soroosh
 Chandani
Sompura
 Vanessa Kaye
 Allison Kreis
Plant Environments
 Plants can live in extreme
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climates.
Not all plants grow all
over the world.
Small changes have
enabled plants to survive
in certain environments.
Many elements make up
plant’s environment.
E.g. sunlight,
temperature,
precipitation, & natural
community.
Biomes: Natural
Communities
 6 Biomes: tundra, forests,
chaparrals, grasslands,
savannas, & deserts
 Forests cover 1/3 of the
earth’s land
 3 major groups:
coniferous forests,
temperate deciduous
forests, & tropical rain
forests
Plant 1
 Dracaena: temperate
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deciduous plant
Temperate deciduous
forests cover large areas
of North America.
Most areas have cold
winters & warm, wet
summers.
Mostly called broadleaf
trees
Lose leaves every fall &
grow new ones in spring.
Plant 2
 Hawaiian Ti Plant: tropical
plant
 Grow in warm, wet weather,
year round.
 Most are broadleaf, & do
not lose leaves completely
 Heavy rainfall occurs
throughout the year.
Plant 3
 Lantana: desert plant
 Deserts cover about 1/5
of the earth’s land.
 All deserts receive little
rain & have either rocky or
sandy soil.
 In most deserts, the
temperature rises above
100º F, for most of the
year.
Plant 3 (Cont.)
 Desert plants are
dispersed.
 Roots of most plants
extend over large areas,
to capture as much water.
 They usually have small
leaves to conserve water
by reducing surface area
from which transpiration
occurs.
 Stomata are closed during
the day.
What is a stoma?
 Pore-like structure on
leaves and stems
 Pore is surrounded by
guard cells with
bands of cellulose
micro fibrils
Function of Stomata
 Allows CO2 to diffuse
into the leaf, while
water vapor diffuses
out
 Controls the amount
of gas diffusion and
water transpiration
Environmental Factors
 Stomata will open if:
There is light
 Low levels of CO2
in the leaves
 Stomata will close if:
 Plant is losing a lot
of water
 It is nighttime (for
most plants)

Mechanism to control
opening of the pore
 Proton pump
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activated
Active Transport of
K+ into the cell
Increase in negative
water pressure
Water enters cell
Increase turgor
Pore opens
Mechanism to control
closing of the pore
 Proton pump
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deactivate
K+ leaves via
passive diffusion
Water follows via
osmosis
Decrease turgor
Pore closes
Procedure:
 Materials:
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Get 3 plants
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Tropical plant
Desert plant
Temperate deciduous
plant
Eye dropper
Small plastic measuring
cup
Nail polish
Scotch tape
Plastic bags
Microscope with slides
Beginning of first 24-hr
period
 Give water to plants
90mL of water to
each with an
additional 30mL to
the desert plant
 Cover each plant with
a plastic bag, leaving
a small opening (~2-3
in) at the bottom

Beginning of second 24-hr
period
 Carefully remove bags
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from plants
Using eye dropper,
collect water-droplets
from leaves
Empty dropper contents
into measuring cup,
while counting how
many drops were
collected
Record data
Give water to each of the
plants
 30mL of water
End of second 24-hr period
 Measure amount
of water released
by each plant
 Record data
Third 24-hr period
 Add 30mL of
water to each
plant
 Measure amount
of water released
by each plant
Final Steps
 Select leaves to view
under microscope
 Cover portion of leaf
with nail-polish and
let dry
 Pull nail-polish layer
off leaf with scotch
tape
 Place the tissue layer
on a slide and focus it
under a microscope
Results
Day 1: April 12, 2003
Plant:
Tropical
Desert
Temperate
Drops of Water:
0
0
0
Results (Cont.)
Day 2: April 13, 2003
Plant:
Tropical
Desert
Temperate
Drops of Water:
9
0
0
Results (Cont.)
Day 3: April 14, 2003
Plant:
Tropical
Desert
Temperate
Drops of Water:
26
0
0
References
 “Plant,” World Book. 1999 World Book, Inc.
Chicago IL.
 “Desert,” Microsoft Encarta Encyclopedia 2000.
1993-1999 Microsoft Corporation.
 http://users.rcn.com/jkimball.ma.ultranet/Biolo
gyPages/G/GasExchange.html.