Download Topic 9.1-9.2 Notes

9.1 & 9.2 Transport in Xylem & Phloem of Plants
TOPIC 9: PLANT BIOLOGY
1 – WATER
PROPERTIES
Read & Consider Understandings
9.1.1 – 9.1.5 & 9.2.2
• List water’s unique
properties.
WATER MOVEMENT
 Xylem
structure
 Evaporation
 Cohesion
 Adhesion
 Incompressible
Osmosis Review: passive movement of
water molecules from a region of lower
solute concentration to a region of
higher concentration.
Isite.lps.org
MINERAL UPTAKE



Mass Flow – facilitated diffusion
Active Transport – ATP used
Mutualistic Relationship – with mycorrhizal fungi
Mineral uptake increases solute concentration in
the roots driving osmosis of water into the plant
with no energy expenditure.
1.
2.
3.
4.
Water is rapidly
absorbed by roots
Absorption creates
strong upward pressure
in xylem
Water moves to replace
that lost via evaporation
from leaves
Water replenishes inner
cells as it travels
Draw the structure of
primary xylem – page. 291, 296
ROOT PRESSURE
TENSION FORCE
The adhesive property of water and evaporation forces carry water to all
parts of the plant, supplying large central vacuoles. Hydration provides
tension forces giving the plant structure rigidity.
XEROPHYTES

Xerophytes – plants of permanently dry and arid
conditions.
Exceptionally thick cuticle
 Thin hairs on epidermis
 Few stomata
 Stomata in pits
 Leaf rolled or folded when flaccid
 Superficial roots
 Deep extensive roots
 C4 & C3 photosynthesis
 CAM metabolism

Read & Consider Understandings 9.1.1 - 9.1.2
2 - TRANSPIRATION
• Define transpiration.
TRANSPIRATION

The evaporation of water through stomata of
green plant leaves – driven by necessary gas
exchange.
ACTIVE TRANSPORT REVIEW

Metabolic energy drives transport across cell
membranes. This transport occurs against a
concentration gradient so that cells may “stock
up” on essential ions.
STOMATAL CONTROL

Each stoma is surrounded by two elongated
guard cells attached to epidermal cells and to
one another. Guard cells open and close in
response to turgor pressure controlled by
concentration of potassium ions.
 Turgid
cell = open
 Flaccid cell = closed
Read & Consider Understandings
9.2.1 & 9.2.3 – 9.2.5
3 - TRANSLOCATION
• Besides water, what do
plants need to transport?
PHLOEM STRUCTURE
SOURCE  SINK
ACTIVE TRANSPORT

Phloem is living and actively
transports nutrients. Nutrients
may occur in either direction by
mass flow:
 Solutes
are loaded into sieve tubes
(ATP)
 Solutes flow from areas of high
pressure (areas with sugar)
 Water flows in to increase pressure
 Sugar is moved to cells (or sink areas)
and pressure decreases.
XYLEM VS. PHLOEM
Compare and contrast
characteristics of xylem
and phloem using the
information on page
295.
Identify xylem and
phloem in stained
mircographs – see page
296.
WORKS CITED






Pennsylvania DEP. "Water - Transpiration." Environmental
Education. DEP, n.d. Web. 4 May 2015.
"Pruning Grape Vines - How to Prune HQ." How to Prune HQ.
N.p., n.d. Web. 04 May 2015.
"Tips: Targeted Intervention for Proficiency in Science."
Science Tips. Regional Professional Development Program,
n.d. Web. 04 May 2015.
"Transport in Plants - Phloem Structure." Transport in Plants.
N.p., n.d. Web. 04 May 2015.
"Water and Carbohydrate Transport in Plants." Study Blue.
N.p., n.d. Web. 4 May 2015.
Wiki Kids Ltd. "Transpiration in Plants." Wonder Whiz Kids.
N.p., n.d. Web. 4 May 2015.