Vascular plants transport water and nutrients between roots, stems, and leaves using two types of transport tissue: xylem and phloem. Xylem transports water and minerals up from the roots through hollow tubes called tracheids and vessel elements. Phloem transports sugar made in leaves to all plant parts through tubes composed of living cells. Substances move through plants via diffusion, osmosis, and active or passive transport across membranes.

1. Vascular tissue

2. PLANTS
Vascular plants need to
transport substances
between the roots,
stems, and leaves.
Xylem – transports
water and nutrients
from soil (i.e.
minerals)
Phloem – transports
sugar
Vascular tissue

3. PLANTS
Some key terms:
Diffusion
Osmosis
Passive Transport
Active Transport
Vascular tissue

4. PLANTS
Vascular tissue
Diffusion: Substances move from areas of high concentration
to areas of low concentration.

5. PLANTS
Vascular tissue
Osmosis: Diffusion of water
Water can diffuse into and out of cells based on
concentration of solute inside and outside a cell.

6. PLANTS
Vascular tissue
Passive transport: Movement of substance across a
membrane without using energy
Passive transport relies on diffusion and concentration
gradients.

7. PLANTS
Vascular tissue
Active transport: Movement of substances across a
membrane using energy against concentration gradient.

8. PLANTS
Xylem
-Transports water.
-xylem is made up of long
hollow tubes formed by
non-living cell walls, called
tracheids or vessel
elements.
-This non-living matter was
once living. (cells die,
leaving cell walls as tubes)
Vascular tissue

9. PLANTS
Xylem
Tracheids
Vascular tissue

10. PLANTS
Xylem
Vessel elements
Vascular tissue

11. PLANTS
Xylem
Tracheids vs. vessel elements
Vascular tissue

12. PLANTS
Into the roots…
In the roots, water
crosses* through the
cortex.
Then it must pass
through the
endodermis.
The Casparian strip
of the endodermis
blocks substances from
passing between
endodermis cells.
Vascular tissue

13. PLANTS
Into the roots…
*Water either enters
the cortex cells by
1) osmosis from cell
to cell
2) flows between
cells.
Minerals are actively
pumped across cell
membranes into the
xylem.
Vascular tissue
H2O

14. PLANTS
Into the roots…
Root pressure –
nutrients pumped into
the xylem cause water
to follow by osmosis
Vascular tissue

15. PLANTS
Into the stem…
Water has to move
against gravity in the
stems.
Accomplished by root
pressure and capillary
action.
Vascular tissue

16. PLANTS
Into the stem…
Capillary action –
water molecules stick
to each other and can
rise up narrow tubes
(like the xylem)
Capillary action
increases as the
diameter of the tube
decreases.
Vascular tissue

17. PLANTS
Into the leaves…
Water moves to the
leaves due to
transpiration.
Transpiration –
Evaporation of water
through stomata of
leaves
Vascular tissue

18. PLANTS
Plants need water to maintain turgor pressure.
Turgor pressure – pressure caused by fluid
pushing against the cell wall
Without turgor pressure, plants will wilt
Vascular tissue

19. PLANTS
Phloem
-Transports dissolved
nutrients (food)
-Phloem tissue is made up
of
living tissue
-Made of
-companion cells
-sieve tube element
-sieve plate
Vascular tissue

20. PLANTS
Phloem
Companion cell
Assists the survival of
sieve tube cells
Vascular tissue

21. PLANTS
Phloem
Sieve tube (cells without a
nucleus forming a hollow tube)
Sieve plate (perforated
end of sieve tube cells)
Vascular tissue

22. PLANTS
How does sugar move
through the phloem?
Both active and
passive transport from
source cells to sink cells.
Source cells: Cells with
high concentration of
sugar (i.e. leaf cell)
Sink cells: Cells with
low concentration of
sugar (i.e. root cell)
Vascular tissue

23. PLANTS
Phloem & tree sap
-In plants, roots store STARCH, a
polysaccharide which is NOT soluble in
water.
-Starch is broken down into SUCROSE,
a disaccharide which IS soluble in
water.
-In the spring, the SUCROSE is then
transported from the roots (where it is
stored during the winter) to the
developing leaves through phloem.
-The leaves convert the SUCROSE into
glucose, a monosaccharide.
Vascular tissue

24. PLANTS
Phloem & tree sap
-The glucose provides energy for the
GROWTH OF LEAVES.
-Once leaves have grown, they can
perform PHOTOSYNTHESIS to produce
their own glucose.
-Excess glucose is converted into
STARCH in the chloroplasts (an
organelle).
-The STARCH is then converted into
sucrose, which is transported to the
ROOTS through the phloem.
Vascular tissue

25. PLANTS
Phloem & tree sap
-The carbohydrate that plants transport
in the phloem is SUCROSE, a
disaccharide.
-Sucrose is converted into the
polysaccharide STARCH in the roots
-Sucrose is converted into the
monosaccharide GLUCOSE in the leaves
in early spring.
Vascular tissue

26. Glucose
(leaves)
Sucrose
(stem)
Starch
(roots)
-winter storage
PLANTS
Phloem & tree sap
Summer and Fall
Summer and Fall
Spring
Spring
Vascular tissue