C4 Transport Flashcards
types of vascular tissues
xylem and phloem
function of xylem tissues
1) to transport water and mineral salts absorbed by the roots to the leaf and stems
2) to provide mechanical support to the plant
function of phloem tissues
1) to transport organic compounds which are synthesized by the leaves through photosynthesis to the stem and roots
examples of vascular plants
mango tree
examples of non-vascular plants
alga, moss
composition of xylem
1) xylem vessels and tracheid
structural adaptions of xylem tissues
-
composition of phloem
companion cell and sieve tube
structural adaptions of phloem tissues
-
three movements that helps the transportationn of water from soil to leaves
1) traspirational pull
2) capillary action
3) root pressure
explain transpirational pull
is produced when the water that is evaporated from the stoma, pulls water from the leaves
explain capillary action
is produced from adhesion force and cohesive force of water molecules which moves water upwards in stem against gravity
explain root pressure
transport water from soil into the xylem vessels of root via osmosis
how does water moves from root to xylem vessels
1) The water potential of the root hair cell is lower compared to the water potential in the soil
2) This is because mineral ions are actively pumped by root hair cell into the vacuole, causing the cell sap of root hair cell to have low water potential compared to the soil
3) Water diffuses from the soil into the root hair cell and epidermal cell via osmosis
4) The high water potential in the root hair cell causes the water to diffuse from root hair cell into the cortex via osmosis
5) This condition causes osmosis to continuously occur throughout the cortex, endodermis and pericycle layeres.
6) This causes root pressure to push water into the xylem vessels of the leaves and then into the xylems vessels of the stem.
How does water moves in the xylem vessels
1) For tall plants, root pressure cannot transport water to the leaves, especially the shoots
2) Therefore the movement of water is also helped by transpirational pull and capillary action
3) the adhesion and cohesion force produces a pulling force which can continuously moves the water in the xylem vessels
4) When transpiration process occurs, the water diffuses out as water vapour from the spaces between the cell to the surrounding through opened stoma
5) The spongy mesophyll cells lose water and have low water potential compared to adjacent cells
6) water molecules diffuses from the neighbouring cells via spongy mesophyll cells by osmosis
7) This movement produces a force, transpirational pull that pulls water molecules in the xylem vessel of the leaves to the outside of theleaves.
definition of phytoremediation
1) is one of the treatment methods which uses plants for the purpose of degradation, extraction and elimination of pollute substance from soil and water
importance of phytoremediation
1) eliminating heavy metals
2) trapping harmful nutrients and microorganisms
Uses of phytoremediation
1) Sunflower
- hyperaccumulator
- eliminate heavy metals (zn,pb,cu)
- eliminate radioactive substances (caesium, strontium)
2) water lettuce
- treat water waste
- fast growth rate
- accumulate heavy metals
- absorb nutrients in waste plant
3) water spinach
- absorb mercury from soil
- absrob heavy metals such as cadmium from water
Definition of translocation
is the process of transporting organic substances such as amino acids, sucrose and hormones in phloem from leaves to other parts of the plants such as stems and roots
Pathway of translocation
1) Sucrose is actively pumped into sieve tube
2) The transport of sucrose into the sieve tube through companion cell from the leaves reduce the water potential of sieve tube. This causes water to diffuse from the xylem vessles into the sieve tube via osmosis
3) the water diffusion increases the hydrostatic pressure in the sieve tube
4) The increase in hyrdostatic pressure causes the phloem sap to pushed along the sieve tube to another organs of plants
5) The phloem saps is transported from the sieve tube to other parts via active transport
6) The high water potential in sieve tube causes water to diffuse return into xylem vessels
7) Transpiration pulls the water along xylem vessles agains the direction of gravitational pull
