Botany
Spring 2006
Lake Tahoe Community College
Instructor: Sue Kloss
_______________________________________________________________________________________________________
Chapter 11
_______________________________________________________________________________________________________
Ch. 11 Absorption and Transport Systems
I. Transpiration
A. Transport and Life
1. Ps requires carbon and water
2. water must be transported from roots to leaves.
3. Plant also needs a system for transporting minerals
4. system for transporting carbohydrates from photosynthetic organs
B. Transpiration and Water Flow
1. water is most abundant compound in a living cell.
2. Many factors affect flow of water in soil, air and cells
C. Water potential defines the direction of water flow
D. Transpiration pulls water through the plant
1. diffusion of water vapor through the stomata
2. flow of water within leaves
3. flow of water through xylem
4. water flow through roots must pass through at least 2 plasma membranes
5. water flow through soil is pulled along by capillary forces as it leaves the soil and enters the root.
6. Control of water loss - daylight causes K+, Cl- into guard cells, pulling water in, opening stomate.
II.
Mineral Uptake and TransportA. Mineral Nutrients are solutes in the soil solution
1. soil types differ in many characteristics
2. differ in depth, chemistry, texture, and sequence of layers.
3. plants roots can only take up elements that are in solution
4. soil formation
5. N fixation
B. Minerals are actively accumulated by root cells
1. the xylem
2. ions are replaced in the rhizosphere
3. growth of the root
4. roots can either passively attain ions in solution in the soil water, or it can actively pump them in.
5. some roots are associated with mycorrhizae
6. Ions are transported from the root to the shoot;
7. Root pressure is result of osmotic pump
8. when ions accumulate in the stele, it draws water in as well resulting in increase
III.
Phloem Transport
A. Osmosis can pump solutions
B. Plant use osmotic pumps to transport sucrose thru sieve tubes
Ch. 11 Lesson Objectives
adhesion
capillary forces
Casparian strip
cation-exchange capacity
cohesion
differentially permeable
diffusion
horizons
hydrostatic pressure
osmosis
osmotic pump
permanent wilting point
root pressure
soil
temporary wilt
turgor pressure
water holding capacity
water potential
Lesson Objectives/Homework Questions Ch. 11
1. How does water potential affect the flow of water in a plant?
2. What substances move into and out of plants? Explain how these materials move in and out of plants.
3. Of what importance is water to a plant? List the important functions water serves in plants.
4. Describe all the factors (e.g. diffusion, osmosis, capillary action, adhesion, cohesion etc) that affect flow of water in
soil, air and cells.
5. How does transpiration affect water flow in plants?
6. Describe 5 or 6 steps in the above process.
7. Of what importance are minerals in plants?
8. How are soils formed? What important characteristics do they have that affect plant productivity?
9. What is root pressure?
10. Explain how stomates function and why they are important.
11. Give three examples of macronutrients and 3 examples of micronutrients and explain their importance to plants.
12. Diagram the pathway taken by a single water molecule that by chance is carried from the soil to a leaf of a tall tree
and then returns from the leaf to the roots of the same plant. Include in your diagram the key cells and tissues through
which this movement occurs.