Transcript Plant Transport presentation

Superlatives!
World’s oldest almost 10,000
Years old
• Movement of water animation
• Leaf cross section
Plant cell types
• Parenchyma: relatively unspecialized with
a primary cell wall
• Schlerenchyma: thick secondary cell wall,
usually with lignin, protoplast gone at
maturity
• Collenchyma: primary cell wall with
thickened corners
Plant tissue types
• Xylem: water conducting tissue made of several
types of cells, tracheids, vessel elements and
other cells
• Phloem: distributes the carbs. made by
photosynthesis, sieve tube elements and
companion cells but other cells are present also.
• Epidermis: outermost layer of cells, secrete
cutin that makes up the cuticle, guard cells that
form stomata and root, stem and leaf “hairs”
Xylem!
• Tracheids are the earliest to evolve, fiber like
with a lignified secondary cell wall
• Cells overlap with each other with a series of
membrane covered pits that from a “tube”
connecting the roots to stem to leaf petiole to
vein for water transport.
• Vessel elements evolved later and found only
in flowering plants, they have a larger
diameter and have holes instead of pits to
allow for more efficient water flow.
Tracheids
Phloem
• Companion cells have a nucleus, seive
tubes do not. They are associated with
each other via plasmodesmata and the
companion cells function in phloem
loading. As with xylem, phloem may
contain fibers and parenchyma cells.
Meristems
• Apical – located at tips plant gets longer
• Lateral – located as cylinders of dividing
cells running the length of the plant from
root to stem to leaf petiole to vein – plant
grows wider
Primary versus Secondary
• Primary – herbaceous plants – only type of
growth
• Secondary – thickening of the roots and
shoots, product of lateral meristems. One
lateral meristem replaces the epidermis
with a secondary dermal tissue such as
bark. A second lateral meristem adds
vascular tissue.
Drawings!
• The teacher will now diagram with you the
arrangement of these tissues in roots,
stems and leaves on mono and dictot
plants.
Do It NOW!
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Through what tissue does water move in a plant?(1)
What two main cell types make up this tissue in
angiosperms?(2)
Are these cells alive at functional maturity?(1)
What mechanism moves water through a plant?(1)
Through what tissue do organic materials move in a
plant?(1)
What two main cell types make up this tissue?(2)
Are these cells alive?(1)
What process moves organics (sucrose) in a plant?(2)
Movement of carbohydrates
The Pressure Flow Model(Hypothesis)
• Remember that in the
phloem tissue, there
are sieve tube cells
and companion cells
that are living cells
responsible for the
movement of organic
materials in the plant.
Remember that the root and shoot
would have apical meristems
First Let’s review
• The next few slides are cross
sections of moncots and
dicots. Make sure you include
these diagrams with your AP
Lab 9
Lateral root
arising from the
pericycle the
layer of cells
interior of the
endodermis
What is a legume?
Plant that grows bacteria in their roots that
fix nitrogen.
Bumpy roots!!!
Leghemoglobin is a protein that absorbs
oxygen.
Peanuts, soybean, clover, beans…
Mycorrhizae – fungi associated
with roots
Helps plants to absorb water and minerals
as an extension of their root system.
Fungi break down organic material in the
soil and create usable forms of nitrogen –
ammonia, nitrates and nitrites.
NPK
Nitrogen – proteins, nucleic acids
Phosphorous – nucleic acids
Potassium – help controls water movement
by helping the plant to open and close
stomata.
Dicot Root Cross-Sections
What is this???
• You will have a lab
practical which is a
quiz on which you will
be required to identify
the organs, tissues
and functions of the
items as viewed on
the microscope –
good practice for
college!!!!
1.Why do plants have guard cells and
stomata?
2.Explain how guard cells operate in detail.
3.Are there more stomata on the top or
bottom of the dicot leaf?
4.Explain your results.
5. If the total leaf area on a plant is 4
centimeter squared, and there are 10
stomata for each millimeter squared, how
many stomata are on the entire surface of
the leaf?
Movement across membranes
• Diffusion – Carbon dioxide, Oxygen
• Osmosis – Water
• Ions – requires transport proteins
Proton Pumps
• ATP is hydrolyzed to ADP. The net
release of energy is used to move H+ ions
across the membrane against the gradient
– Proton gradient generates a negative
charge inside the cell compared to the
positive charge outside the cell a.k.a a
membrane potential. Plants use this
potential to power the absorption of K+,
NO3- and others into roots.
Water Potential Review