Download 1.-xylem-and-phloem

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
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
The need for transport
• All cells need the same basic things...
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.
Transport in multicellular
organisms
• The body’s surface
area is small in
relation to volume
• Cells are too far
Don’t forgot that plants
from the
are also multicellular
“absorbing” organs
organisms.
Let’s have a look at how • Transport system
they are organised ...
is needed to deliver
substances to all
body cells
Level of organisation in
Multicellular Organisms
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?
What transport system carries this?
In what direction?
Plant Transport Systems
Plant Transport
CROSS-SECTION
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.
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.
Xylem vessel
Under a
microscope
Investigating Water transport in
a plant
Investigating Water transport in
a plant
Investigating Water transport in
a plant
Investigating Water transport in
a plant