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1. title Transport in flowering plants

2. Transport in flowering plants is provided by vascular tissue xylem phloem • transport • water • substances dissolved in water • transport • organic nutrients

3. leaf Distribution of vascular tissue in dicotyledonous plant midrib vein leaf vein xylem phloem

4. stem Distribution of vascular tissue in dicotyledonous plant xylem phloem Vascular bundle cortex

5. root Distribution of vascular tissue in dicotyledonous plant xylem phloem cortex

6. xylem vessels Xylem cells xylem tissue is made up of xylem vessels • thickcellulose cellwallswith lignin • dead, hollowcells • no cross wallbetween cells • provide support to plant other than transport

7. phloem cells Phloem cells phloem tissue is made up of sieve tubesandcompanion cells 1. sieve tubes sieve tube • living cylindrical cells(cytoplasm,no nucleus) • thincellulose cellwallswith no lignin • joining end to end to form long tube • substances can pass from cell to cellthroughsieve plates

8. phloem cells Phloem cells phloem tissue made up of sieve tubesand companion cells 2. companion cells companion cell • narrow cell with a nucleus / numerous organelles • support the metabolic activities of the sieve tubes

9. The plant wilts The cells of leaves lack water • Turgidity of cells provides support to plants

10. Osmosis in plant cells • In a solution withhigherwater potential • water moves inby osmosis • cellturgidfully turgid • In a solution withlowerwater potential • watermoves out by osmosis • cellflaccid  plasmolyzed

11. Water Balance in plant lose water • evaporation • transpiration gain water • absorption by root

12. Transpiration in plants What is transpiration? • loss of water vapour from surfaces of plants due to evaporation

13. Where does transpiration occur? • stomata ( > 90% ) • lenticels ( < 10%) • waxy cuticle (very small amount)

14. Transpiration through stomata consists of 2 steps : • Water evaporates into the air space • Water diffuses out through the stoma water lost from leaves

15. Water is replaced by : • As a result, cells draw water from the xylem, pulling water up the plant. • Water is lost from the cell surface (cell wall), which is replaced by the water in the cell. Each cell then pulls water from its neighbouring cells. through cell wall water lost from leaves through cytoplasm and vacuoles

16. transpiration rate light intensity Light intensity • more CO2 for photosynthesis light intensity   stomata open more widely  SA for diffusion of water vapour   more water vapour diffuses out  transpiration rate   light intensity  Temperature

17. transpiration rate 15 20 25 30 temperature (oC) Temperature temperature  • rate of evaporation  • diffusion gradient  • rate of diffusion of water vapour  • more water vapour diffuses out • transpiration rate 

18. transpiration rate 0 20 40 60 80 100 relative humidity of atmosphere (%) Relative humidity relative humidity  • concentration of water vapour in the surrounding air lower • diffusion gradient of water vapour  • water diffuses out more  • transpiration rate

19. transpiration rate 0 8 16 24 wind velocity (km/h) (air movement) Air movement air movement   • remove water vapour accumulating near the leaf surface • diffusion gradient of water vapour  • rate of diffusion   • water vapour diffuses out more more • transpiration rate  

20. Investigation To Measure the Rate of Transpiration by Using a Simple Potometer

21. graduated capillary tube leafy shoot air/water meniscus tap reservoir What are the environmental conditions under which transpiration occurs quickly ? Ans:It is under dry, warm and windy conditions.

22. graduated capillary tube leafy shoot air/water meniscus tap reservoir Does this apparatus give you an accurate measurement of the rate of transpiration ? Ans:No. It is because it only measures the rate of water uptake by the leafy shoot … Ans:In addition, it is too small to fit the whole root system and this may affect the rate of water uptake.

23. graduated capillary tube leafy shoot air/water meniscus tap reservoir Sometimes you may introduce an air bubble into the capillary tube. State the advantage of this method. Ans:Movement of the air bubble is easier to observe than that of air/water meniscus.

24. graduated capillary tube leafy shoot air/water meniscus tap reservoir Sometimes you may introduce an air bubble into the capillary tube. State the disadvantage of this method. Ans:Friction between the capillary wall and the bubble may affect the movement of bubble.

25. Investigation To Measure the rate of water uptake and water loss of a plant using a weight potometer

26. V1 V2 W1 24 hours W2 Change in volume in burette = (V2 – V1)cm3 = amount of water uptake Change in weight of the whole set-up = (W1 – W2)g = amount of water loss

27. V1 V2 W1 24 hours W2 Rate of water uptake = (V2 – V1) / 24 cm3/hr Rate of water loss Water retained = (W1 – W2) / 24 g/hr Photosynthesis / new cells 1cm3 water = 1g water Rate of water loss > Rate of water uptake

28. in flowering plants provided by consist of carries carries Concept diagram Transport vascular tissues phloem xylem water organic nutrients

29. water forms a continuous stream inside by transpiration pull Transport of water and mineral salts • water • mineral salts Xylem vessels transport water drawn out of xylem vessels to replace water loss through leaftranspiration water in xylem vessels is moved up as plants transpire minerals and other substances dissolved in water can be transported up the plant

30. Transport of organic nutrients through sieve plates Phloem transport - organic nutrients bytranslocation bud moving up to growing part organic nutrients made by photo-synthesis moving down to growing fruit and root for storage water and minerals absorbed by roots