own work

2. Transportation in plants

3. Transport system

4. Reason for transport system
•Unicellular organisms
They can transport materials likeoxygenand urea in and
out of their bodies.
•Multicellular organisms:
Most of the cellsinsidethe organisms are too far from
the surface of their bodies and diffusionand osmosis are too
slow to be reliedon.
A transportation systemis required for food and oxygen
to be brought efficientlyfromone placeto another.
Diffusionand osmosis would take place betweenthe
transportsystemand the cell.

5. Transport system in plants
There are two transport systemin plants.
One that transports waterand minerals fromroot to all other parts .
Thesevessels are called xylemvessels.
Another vessels transport sugars (sucrose) and amino acids made in
leaves to all the Other parts of plant. These are called phloemvessels.

7. •Xylemconsist of mainly xylem vessels that
are made up of deadcells.
•Xylemcells are elongatedcells.
•Inner walls of xylemvessels are
strengthened are lignin.
•Lignindeposited in theform of rings or
spirals.
Xylem vessels

9. Adaptations of xylem
vessels
Absence cross walls
maintains a continuous lumen.
Protoplasmdisintegrate
allows waterto move efficiently.
Dead empty tube
maintains a continuous lumen.
Lignified walls
walls are rigid
xylemwill not collapse
supports the plant

10. •Consists of man sieve tubes and companion
cells .
•Sievetubes consist of columns of sieve tube
cells that are elongatedand thin wall.
•Companioncellsprovide thenutrients and
help the sieve tube cells transport .
•Manufacturedfood (sucrose)
Phloem cells

12. Adaptation of Phloem cells
Bi-directional sucrose flow
Food can be transported to all parts of the plant.
Crosswalls perforatedby sieve tubes
Single row of thinelongatedwalls with minute pores
Living cellsto conduct thefood in the tube
Companion cell present
Consists of protoplasmand mitochondria
Assists sieve tubes in transport of food
Provides energy requiredfor active transport
Whendead, sieve elements will die off

13. Xylem
Conduct water and mineral salts from roots to
stem and leaves Provide mechanical support
for plant.
Phloem
Conduct manufactured food(surose and
amino acids)from the leaves to the other
parts Of plants.
Functions of xylem and phloem

14. Root hair cells
Thin hairlike outgrowth of an epidermal cell just behind
the tip; absorbs nutrients from the soil.Hair like structures
found on the epidermis cells of the root that allow a much
larger surface area for water to be absorbed and used by
the plant
Plants absorb waterand minerals fromthe
soil through the root hairs.
Root hair cellsabsorb water and nitrates from
the soil efficiently.
They help to hold the plant more firmly to the
ground.

15. Adaptation of root hairs
Finger-like extensions
• Increases surface area to volume ratio
• To absorb waterand mineral salts at a faster rate
Lower water potential
• allow osmosis and diffusionof nitratesto take place
Large vacuole
• To absorb as much water as it canhold
Is a living cell
• carries out respiration
• This provides energyfor active transport to
take place when water potential lower in the soil

16. Translocation
Translocation is the process of transporting food substances
downwards from the leaves to All other parts of the plants,
through the phloem.

17. Translocation of organic solute
Phloemtubes are delicate structures, thesetubes are punctured by a
small
Greenish insect, aphidduring its feeding fromthe young shoots of a plant.
oAphids are fluid(phloem) feeders.Theysuck sugary substance fromphloem tissues.
The phloemcontents are continuedto come out .
On examining the contents it is found that it contains up to 30percent
sugars
(sucrose=glucose+fructose)remaining 70 percent is water.

19. Movement of water in plants
The uptake or loss of water by cellstakes place by osmosis.

20. oThe movement of watermolecules fromhigher concentration to a low
concentrationis calledosmosis .if water moves by osmosis intoa cell the
processis called
And if the watermoves out of the cell it is called
Uptake of water by roots
oThe cell wall of epidermal cells of roots is freely permeable to water
and other minerals.
oThe cell membrane is however, is partially
permeable to some substance.

21. oThe waterwhichenters the epidermal cellsmoves along the concentration
gradient and passes throughcortex,endodermis,pericycle and ultimately to
xylemcells.
There are three pathways taken by
water to reach the xylem tissues:

22. Apoplast
pathway
(cell wall to
cell wall)
Symplast
pathway
(cytoplasm to
cytoplasm)
Vacuolar
pathway
(vacuole to
vacuole)

24. The movement of watertakes placethrough TACT Mechanism
Transpiration
Adhesion
Cohesion
Tension
Ascent of sap
The upward movement of water from the root to aerial parts of the
plant body is called ascent of sap or often called translocation of water

25. Transpiration
Transpiration is the evaporation of water
Into the atmosphere from the leaves and stems of
plants.
Ascent of sap

27. Adhesionis the attractive force betweenwater molecules and other substances
Because both water and cellulose are polar molecules so there is the strong
attractionfor waterwithinthe hollowcapillaries of the xylein.
Adhesion also helps hold water in the xylem when transpiration is not
occurring.
Adhesion:
Ascent of sap
It is attractionamong water molecules which hold
watertogether forming a solid chain- likecolumn
withinthe xylemtubes. The water molecules
formhydrogen bondsbetweenthem.
Cohesion

28. Tension
It is providedwhenthis waterchainis pulled up in the xylem.
Transpiration provides the necessary energy. Tensionis between the
molecules of water by hydrogenbonds.
Ascent of sap

30. Opening and closing of stomata

31. Low level of CO2
CO2+H2O (dissociate in ions)
H⁺
HCO3
Activate the k+ channels (epidermal cells)
K+ move towards the guar cells
It flows the
movement Of H2O
Stomata will
open
Guard cells become turgid

33. ANY
Question ???

34. Thank You