Transcript plants – day 2

PLANTS – DAY 2
TRANSPORT MECHANISMS WITHIN VASCULAR
PLANTS
MATERIAL DISTRIBUTION IN A
VASCULAR PLANT
WATER
GLUCOSE
CELLS IN THE LEAF
During photosynthesis, the leaf
must have a constant supply of
________________ and release
_________it produces; this
exchange of gases with the
environment is regulated by tiny
pores called _____________, found
in epidermis of leaves or sometimes
stems
TRANSPIRATION



Stomata also allow water vapour to
escape the leaf. Loss of water vapour in
plants is called _________________ –
water diffuses and evaporates into the air
spaces of the leaves and out to the
atmosphere through stomata
Stomata are accompanied by
_____________________: these cells
regulate the opening and closing of each
stoma (singular of stomata) because when
stomata are open, the plant can get all
carbon dioxide it wants BUT it also loses
water
When stomata are closed, water is
conserved but no carbon dioxide goes in;
it’s a ____________________
CELLS IN THE LEAF



Between the upper and lower surfaces
of a leaf is a photosynthetic region
called _________________, consists of
parenchyma cells containing lots of
chloroplasts
__________________ mesophyll occurs
under upper epidermis, cells shaped like
bricks and tightly packed in one or two
layers; have many chloroplasts and are
MAIN site for PS
___________________mesophyll lies
between palisade meosphyll and lower
epidermis; fewer chloroplasts, are
irregular in shape, are randomly
arranged with large air spaces among
them; air spaces promote rapid
diffusion of carbon dioxide into cells
and oxygen gas out of them
GAS EXCHANGE IN PLANTS




Gas exchange in the leaf done via
___________________: the movement
of molecules (liquid or gas) from an
area of higher concentration to an area
of lower concentration
Movement from an area of higher
concentration to one of lower
concentration is known as moving along
the ____________________________
Creates a
________________________ – a
difference in pressure across a given
distance
Pressure gradient results in a NET
FORCE that is directed from high to low
pressure and the force is called
‘Pressure Gradient Force”
DIFFUSION OF CARBON DIOXIDE
LOW
CONCENTRATION
OF CARBON
DIOXIDE (INSIDE
MESOPHYLL
CELLS)
WHY????
________________
CONCENTRAION
OF CARBON
DIOXIDE (IN AIR
SPACES)
CHLOROPLASTS
_________________________
CONCENTRATION OF CARBON
DIOXIDE (IN AIR)
ROOTS IN PLANTS





ROOTS
Extremely important; often larger than its shoot
system; absorb water and minerals from soil,
physically support and anchor plants and store
carbohydrates
Water and minerals enter from roots and are
transported through vascular tissue to stem, leaves
and flowers; carbs produced in shoot system are
transported down to roots for storage
Each root has protective __________________ at
its tip to cover the apical meristems and behind
the cap, the epidermal cells have fine microscopic
_____________________ that increase the roots
surface area for absorption of water and minerals
Center of each root is the vascular cylinder which
contains the vascular tissues,
_________________________ and some ground
tissue
OSMOSIS: WATER TRANSPORT IN
ROOTS

Osmosis: passage of a solvent, such as water, from the dilute side to the
concentrated side of a membrane, filter, or other semipermeable border.
Without added pressure, a solution divided in this way will undergo
osmosis, in order to equalize the concentration of the two sides

Solute:

Solvent:
OSMOSIS




hypotonic solution: a solution
where the concentration of solutes
outside a cell is _______ than that
found inside the cell. Where does
water move to?
hypertonic solution: a solution
where the concentration of solutes
outside a cell is __________ than
that found inside the cell. Where
does water move to?
Visualization:
http://www.stjohn.ac.th/Department
/school/bio_pix/osmosis.gif OR
http://www.youtube.com/watch?v=s
diJtDRJQEc
OSMOSIS – ROOT TRANSPORT IN
PLANTS





________________ absorb minerals
from soil by active transport (requires
energy) and move minerals moved to
center of root
Root hairs increase surface area for
roots to take up more water and
minerals from ground
Minerals are the __________ , water
is the ________________
Lots of minerals inside the root, so
water will diffuse across a
semipermiable membrane (in this
case, the root hairs) and move
__________ the root of the plant
So, this xylem sap is ____________
relative to soil water outside root
PUTTING IT TOGETHER
Water evaporates from internal
leaf cells through the stomata =
called ____________________
Water passes from xylem to
_______ cells
Water enters ___________ from
root tissue to replace water that
moved upwards
Water enters root hair cells by
__________ to replace water
which has entered the xylem
STEMS




Support the plant and serve as a
transport link to and from leaves, roots
and reproductive parts
Stems have _____________________
(xylem and phloem tubes) arranged
together
Vascular cambrium is the name for
lateral meristem tissues in the stems –
helps stems to grow in diameter
Phloem produced to the ___________
and xylem produced to the _________
in stems
TRANSLOCATION






Translocation: process of moving the __________________________
throughout the plant body through phloem
Precise mechanism of this food transport is ___________________
Carbohydrates/glucose made by photosynthesis are moved from leaf
cells to other plant parts via phloem tissue
Phloem, like xylem tissue, forms a continuous pipeline between leaves
and roots
Most accepted explanation of translocation is called the
__________________theory where fluids will low from an area of
higher pressure towards an area of lower pressure
Carbs will flow from their ____________ (where they are made) which
has a higher pressure, to where they are _____________ or used
(__________) which has a lower pressure; the driving force is a
positive pressure gradient from source to sink
PRESSURE-FLOW THEORY
(TRANSLOCATION)
1.
2.
3.
4.
5.
Active transport of sugar
(carbohydrates) into phloem.
Active transport is the
movement of molecules across
a membrane against a
concentration gradient;
requires _________________.
Water follows by __________
Pressure gradient moves fluid
__________ phloem
Active or passive transport of
sugar into root cell
Water follows by __________