transport in living things
DESCRIPTION
Transport in Living Things. Chapter 25 Chapter 25.5 Transport System in Flowering Plants. What did we learn?. Gaseous exchange in the lungs. Movement of substances. Transport of water into roots. Passive process. Diffusion. Active process. Osmosis. - PowerPoint PPT PresentationTRANSCRIPT
Transport in Living Things
Chapter 25Chapter 25.5 Transport
System in Flowering Plants
What did we learn?Movement of substances
Diffusion Osmosis
Passive process Active process
Net movement of molecules from a region of higher concentration to a region of lower concentration
Net movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane
Active Transport
Movement of molecules from a region of lower concentration to a region of higher concentration with the use of energy
Carbon dioxide and
oxygen inside leaves
Gaseous exchange in the lungs
Transport of water into roots
Transport of mineral
salts into the roots
Lesson ObjectivesAt 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
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?
Vascular tissues
1. Xylem 2. Phloem
Xylem tissueStructure• composed of hollow,
nonliving cells (continuous lumen)
• Lignified wallsFunction• transports water and mineral
salts from roots → stem → leaves
• provides mechanical support to plant
Structure of Xylem
QUESTION
• How is the straw similar to the xylem?
Phloem tissue
Structure• Living cellsFunction• Transports manufactured
food (sucrose and amino acids), usually from leaves → other parts of the plant
Identifying a vascular bundle
Identifying a vascular bundle in a dicotyledonous stem
A vascular bundle
cambium
Transverse section of a stem
Why do you think the xylem is positioned on the inside?
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.
Locate the xylem and phloem
phloem
xylem
Leaf structure
phloem
xylem
Transport of water
Structure 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
Entry of water into the plant
Thin film around particle = dilute solution of mineral salts
Entry of water from soil
Sap in root hair Soil solution
Strong solution of sugars and salts
Dilute solution of mineral salts
Low water potential
Higher water potential
Plasma membrane of root hair cell
H2O
Osmosis
Transport of water from root hair → xylem
Low water potential
High water potential
Transport of mineral salts
Transport of mineral salts
Sap in root hair Soil solution
Plasma membrane of root hair cell
Mineral concentration low
Mineral concentration high
Mineral salts
Diffusion
Qn: Can the root hair absorb ions if the concentration is higher in the root hair sap compared to the soil solution?
Transport of mineral salts
Sap in root hair Soil solution
Plasma membrane of root hair cell
Mineral concentration high
Mineral concentration low
Mineral salts?
Active transport
Yes!!!
Summary
Xylem Phloem
Plant Transport system
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
where
Water moves into the root hair cell via OSMOSIS
Consists of
Mineral salts move into the root hair cell
via Diffusion OR ACTIVE TRANSPORT
In the next lesson…
We will be learning about• what is transpiration• what is translocation
• MINI QUIZ!