1. Transport in Living Things
Chapter 25
Chapter 25.5 Transport System in Flowering Plants

2. What did we learn? Transport of mineral salts into the roots
Movement of substances
Passive process
Active process
Active Transport
Diffusion
Osmosis
Movement of molecules from a region of lower concentration to a region of higher concentration with the use of energy
Transport of mineral salts into the roots
Add video: how osmosis works
Net movement is the overall direction of a movement of a substance
Net movement of molecules from a region of higher concentration to a region of lower concentration
Transport of water into roots
Net movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane
Carbon dioxide and oxygen inside leaves
Gaseous exchange in the lungs

4. Lesson Objectives At the end of the lesson, You should be able to:
State what the vascular bundle consists of
Describe the structure and function of xylem and phloem
Identify the position of xylem vessels and phloem in sections of the stem
relate the structure and functions of root hairs to their surface area, and to water and ion uptake
identify the positions of xylem vessels and phloem in sections of a typical dicotyledonous stem and leaf, under the light microscope, and state their functions
relate the structure and functions of root hairs to their surface area, and to water and ion uptake
state that transpiration is the loss of water vapour from the stomata

5. Looking at the rose… How do you turn a white flower into a blue one?
How does the coloured water travel up the stem to the flower?

6. Vascular tissues
Xylem
Phloem

7. Xylem tissue Structure Function
composed of hollow, nonliving cells (continuous lumen)
Lignified walls
Function
transports water and mineral salts from
roots → stem → leaves
provides mechanical support to plant

8. Structure of Xylem

9. QUESTION
How is the straw similar to the xylem?

10. Phloem tissue Structure Living cells Function
Transports manufactured food (sucrose and amino acids), usually from leaves → other parts of the plant

11. Identifying a vascular bundle

12. Identifying a vascular bundle in a dicotyledonous stem

13. A vascular bundle
cambium

14. Transverse section of a stem

15. Why do you think the xylem is positioned on the inside?

16. How to distinguish xylem vessels from phloem in microscopic slides?
Xylem vessels have
Thicker walls
- due to lignified walls (either annular, spiral or pitted) to provide mechanical support to the plant
Larger lumen compared to phloem
Xylem vessels have a darker stain.

17. Locate the xylem and phloem

18. Leaf structure
xylem
phloem

19. Transport of water

20. Structure of root Function of root Presence of Root hairs
Increased surface area
Function of root
Absorb water and mineral salts from the surroundings
Water absorbed from the root enters the xylem

21. Entry of water into the plant
Thin film around particle = dilute solution of mineral salts

22. Entry of water from soil
Plasma membrane of root hair cell
Sap in root hair
Soil solution
Strong solution of sugars and salts
Dilute solution of mineral salts
H2O
Low water potential
Higher water potential
Osmosis

23. Transport of water from root hair → xylem

24. High water potential
Low water potential

25. Transport of mineral salts25

26. Transport of mineral salts
Plasma membrane of root hair cell
Sap in root hair
Soil solution
Mineral concentration low
Mineral concentration high
Mineral salts
Diffusion 26

27. Transport of mineral salts
Qn: Can the root hair absorb ions if the concentration is higher in the root hair sap compared to the soil solution?
Yes!!!
Plasma membrane of root hair cell
Sap in root hair
Soil solution
Mineral concentration high
Mineral concentration low
Mineral salts?
Active transport 27

28. Summary Plant Transport system Consists of Xylem Phloem transports
Water containing dissolved mineral salts from the roots to the leaves
Manufactured food substances (eg. sugars) from the leaves to the other parts of the plant
Mineral salts move into the root hair cell via Diffusion OR ACTIVE TRANSPORT
where
Water moves into the root hair cell via OSMOSIS

29. In the next lesson… We will be learning about what is transpiration
what is translocation
MINI QUIZ!