Transcript Plant Structure and Transport

Bozeman Plant Structure – pg 103
Plant Structure
and Transport
Chapter 35 + 36
Pg 105
Plant Evolution
• Challenges of moving to land
from Green Algae –
Chlorophyta (protist)
• 1. Obtaining H2O
• 2. Transporting H2O
• 3. Preventing desiccation
• 4. Support against gravity
• 5. Reproduction without H2O
1. Bryophytes – most primitive land plant
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– Small and grow close to ground –
no adaptation for growing
against gravity
Antheridium – male gametes
Archegonium – female gametes
– Female gamete surrounds sperm
and prevents desiccation and
injury
Cuticle – waxy coating – prevents
desiccation
Stomata – contain guard cells which
regulate gas exchange and water
loss.
NO innovations for H2O transport –
non vascular
Grow in damp, moist environments
2. Tracheophytes – vascular plants
• Pterophyta
– Seedless or spores
• Kept all the innovations from
Bryophyta
• Added
• Roots – water uptake
• Vascular tissue
– Xylem – transports H20 and mineral
from roots to leaves
– Phloem – transports sugar from
photosynthesis from leaves to rest of
plant
• Lignin – supports the plant against
gravity
• Hormones – regulate development
3. Gymnosperms – seed vascular with
no fruit
• Coniferophyta
• Kept all innovations from
Bryophyta and Pterophyta
• Added
• Ovule (seed) with archegonium
(small)
– Found in cones
• Pollen tube – replaces the
antheridium – no need for H2O
4. Angiosperms – seed with fruit
• Anthophyta
• Kept all innovations from Bryophyta,
Pterophyta and Coniferophyta
• Added
• Ovary (fruit) – surround the ovule (seed)
• Double fertilization – endosperm which provide
nutrients to the developing zygote
• Stamen with pollen – male reproductive structure
– No more antheridium
• Ovule and ovary – female reproductive structure
– No more archegonium
Pg 104
• Bubble Map – Adaptations for surviving on
land
• summary
Angiosperms – Plant Morphology - 107
• Dominant plant on Earth
• Major parts
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Terminal or Apical bud
Axillary bud
Flower – reproductive shoot
Leaf – Petiole + blade
Vegetative branch
Stem – w/ vascular tissue
Node
Internode
Taproot – main root
Lateral roots
Root hairs
Carpel
Stigma
Anther
Style
Stamen
Ovary
Filament
Petal
Sepal
Receptacle
Ovule
The Flower
• Parts to know
• Structure /
Function
– Pistil / carpel
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Stigma
Style
Ovary
Ovule
– Stamen
• Anther
• Filament
– Sepal
– Petal
Angiosperm Plant Types
Angiosperm Plant Types – pg 603
• Monocot – narrow leafed flowering plant such
as a grass, lily, orchid, or palm
• Dicot (Eudicot) – broad leafed flowering plant
such as roses, maples, sunflowers, and squash
Plant Part
Monocot
Dicot
Cotyledon
1
2
Veins in Leaves
Parallel
Netlike
Vascular Tissue - stem
Scattered
Ring
Roots
Fibrous
Taproot
Pollen Grains
1 opening
3 openings
Flower Parts
Multiples of 3
Multiples of 4 or 5
Pg 106
• Venn Diagram or Double Bubble – Monocots
vs. Dicots
• Summarize – Compare and contrast
Bozeman Plant Nutrition and
Transport – pg 109
Plant Transport
Chapter 36
111
REVIEW 
• Transport – movement of molecules
• Passive transport – down a concentration gradient with out
energy
– Osmosis – water
• Aquaporins – assist water through bilayer
– Facilitated Diffusion - large / polar molecules with transport
protein
– Simple diffusion – small molecules directly through bilayer
• Active transport – against a concentration gradient with
energy
– Endocytocis – engulf large molecules
– Exocytosis – remove large molecules
– Pumps – ions / large molecules
Proton Pumps
• Cotransport
• Creates a proton concentration gradient using
ATP so other molecules can passively enter
the plant cell.
– Sugar, NO3-
Pg 110
• Transport (passive and active) concept map
• Give an example of a SPECIFIC substance that
uses each type.
• IQ 36.6
Water Potential and Osmosis - 113
• Water Potential = Ψ
• Water moves from a higher water potential to
a lower water potential
• Ψ = Ψs + Ψp
• Ψs = solute potential (osmotic potential)
– Adding solutes to a solution lowers the solute
potential and there fore the overall water
potential
• Ψp = pressure potential
Osmosis and Plant Cells
• Isotonic – external solute concentration the same as the
internal solute concentration
– Water moves in and out at the same rate
– Dynamic Equilibruim
– Flaccid or wilty
• Hypertonic – external solute concentration greater than the
internal solute concentration
– Water moves out of cell
• Plasmolyszed
• Hypotonic – internal solute concentration greater that
external solute concentration
– Water moves in
– Turgid
• Healthy plant
Initial flaccid cell:
 = 0
s = –0.7
Plasmolyzed
cell at osmotic
equilibrium
with its
surroundings
 = 0
s = –0.9
0.4 M sucrose solution:
 = 0
s = –0.9
 = –0.7 MPa
 = –0.9 MPa
 = –0.9 MPa
(a) Initial conditions: cellular  > environmental . The cell
loses water and plasmolyzes. After plasmolysis is complete,
the water potentials of the cell and its surroundings are the
same.
Distilled water:
 =0
s = 0
 = 0 MPa
Turgid cell
at osmotic
equilibrium
with its
surroundings
 = 0.7
s = –0.7
 = 0 MPa
(b) Initial conditions: cellular  < environmental . There
is a net uptake of water by osmosis, causing the cell to
become turgid. When this tendency for water to enter is
offset by the back pressure of the elastic wall, water
potentials are equal for the cell and its surroundings.
(The volume change of the cell is exaggerated in this
diagram.)
112
• IQ 36.1
Xylem vs. Phloem Transport – Bulk Flow
115
Xylem
Dead Cells – Tracheids
Water and Minerals
Phloem
Living Cells – Sieve Tube
Members
Organic Compounds (sugar)
Unidirectional Movement (up)
Bi-Directional Movement (down,
up, side to side)
Fast – max rate 15 meters / hr
Slow – max flow rate 1 meter / hr
NO ATP - Passive
ATP - Active
Transpiration
Translocation
Bulk Flow – Water and Minerals - 113
• Transpiration – “pulling” of
water from the roots to the
leaves of plants
– Hydrogen Bonding
• Cohesion – keeps H2O together as
it is pulled upward
• Adhesion – keeps H2O from falling
with gravity
– Sticks to the sides of the xylem
Transpiration – pg 748
• Chain Reaction
– Water evaporates through open stomata
– Pulls water from mesophyll cells to the stomata
– Plant cells shrink (plasmolysize) due to the loss of
water
– Tension is created which pulls the water in the xylem
up the plant to replace the water in the plasmolysized
cells
Xylem
sap
Outside air Y
= –100.0 MPa
Mesophyll
cells
Stoma
Leaf Y (air spaces)
= –7.0MPa
Transpiration
Leaf Y (cell walls)
= –1.0 MPa
Atmosphere
Xylem
cells
Water potential gradient
Trunk xylem Y
= – 0.8 MPa
Water
molecule
Adhesion
Cohesion
and adhesion
in the xylem
Cell
wall
Cohesion,
by
hydrogen
bonding
Water
molecule
Root xylem Y
= – 0.6 MPa
Root
hair
Soil Y
= – 0.3 MPa
Soil
particle
Water uptake
from soil
Water
114
• Flow Map – Transpiration
• Summarize
Factors that affect transpiration - 117
• Heat – increases rate
– CAM plants have stomata on the underside of the
leaves that can close to conserve H2O
• Wind – increases rate
• Humidity – decreases rate
• # of stomata – increases rate
Transpiration Regulation
• Guard cells around
the stomata in the
epidermis of the plant
leaf
• CO2 enters, O2 leaves
and H2O evaporates
• Light stimulates the
stomata to open to
allow CO2 to enter for
photosynthesis
Transpiration Regulation
Stomatal closing
Stomatal opening
• 1. Potassium ions move
out of the vacuole and
out of the cells.
• 2. Water moves out of
the vacuoles, following
potassium ions.
• 3. The guard cells shrink
in size - plazmolysize
• 4. The stomata closes.
1. Potassium ions move
into the vacuoles.
2. Water moves into the
vacuoles, following
potassium ions.
3. The guard cells expand
- turgid
4. The stomata opens.
20
116
• Bubble map – Factors that affect transpiration
rates
• Summarize – WHY transpiration is affected.
Link to water potential.
Pg 118-119
• Chapter 35 and 36 EK