1. Growth and Development of different organisms
National 5 Biology
Key Area 6:
The Need for Transport
(a) Plant Transport Systems
National 4 Biology
Key Area 4
Growth and Development of different organisms

2. Learning Outcomes for Topic 6 – Part A
Explain why plants need a transport system
Name the 2 transport systems in plants
Give the function of each of the 2 plant transport system
Be able to identify 7 structures in a leaf
State the function of each structure
State what is meant by ‘transpiration’
Describe the process of transpiration in a plant

3. oxygen for respiration removal of poisonous waste products
The need for transport
All cells need the same basic things...
oxygen for respiration
glucose
removal of poisonous waste products

4. Transport in unicellular organisms
oxygen
poisonous waste products
glucose
Substances move into the cell by diffusion.
This is effective because the cell has a large surface area relative to volume.

5. Transport in multicellular organisms
The body’s surface area is small in relation to volume
Cells are too far from the “absorbing” organs
Transport system is needed to deliver substances to all body cells
Don’t forgot that plants are also multicellular organisms.
Let’s have a look at how they are organised ...
Absorbing animal organs – lungs and small intestines.
Absorbing plant organs – leaves and roots

6. Level of organisation in Multicellular Organisms

7. Think/pair/share What does a plant need from the soil?
What transport system carries this?
In what direction?
What does a plant make in the leaves?

8. Plant Transport Systems

9. Plant Transport CROSS-SECTION

10. Plant Transport Systems
Plants have two systems for the transportation of substances:
Xylem transports water and mineral salts from the roots to the leaves.
Phloem transports sugar up and down the plant.

11. XYLEM TISSUE PHLOEM TISSUE
Dead hollow tube
Companion cell
Sieve plate
Cytoplasmic strands
Sieve tube = the whole thing!
Dead
Hollow tubes containing lignin
Xylem cells are lignified to withstand the pressure changes as water moves through a plant (this stops them bursting)
Living tissue
Sieve tube with a companion cell.
Sugar is transported up and down the plant through cytoplasmic strands.

12. Xylem vessel
Under a microscope

13. Investigating Water transport in a plant

14. Investigating Water transport in a plant

15. Investigating Water transport in a plant

16. Investigating Water transport in a plant