Chapter 4: Transportation in plants Flashcards
1
Q
structural and adaptation of phloem
A
- sieve tube
- no nucleus, ribosome and vacuoles
- allow sucrose molecules pass through sieve tube easily - Sieve plate
- have pores (perforation plate)
- allow organic compound to flow from one to one sive tube - companion cell
- contain mitochondria
- provide energy in form of ATP
- transport sucrose from leaf to sieve tube via active transport
2
Q
3 aid of movement of water and mineral salt in xylem
A
- capillary action
- transpirational pull
- root pressure
3
Q
water move from soil to xylem vessel
A
aid by root pressure
( root hair cells - epidermis - cortex - endodermis - pericycle - xylem )
- mineral salts are actively pumped by root hair cells into vacuole
- water potential of cell sap of root hair cell are lower than water in soil
- water diffuse from soil into root hair cells and epidermal cells via osmosis.
- higher potential in adjacent cell causing osmosis to occur continuously through cortex, endodermis and pericycle
- this cause root pressure to push water into xylem vessels of root and stem
4
Q
capillary action in xylem vessel
A
- adhesion force between water and wall of xylem
- cohesion force between water and water molecules
- adhesion and cohesion force produce a pulling force to move water continuously in the xylem vessel
5
Q
transpirational pull in xylem
A
- when transpiration happens, water diffuse out as water vapour form the space between the cell to surroundings through opened stoma
- spongy mesophyll cell lose water and have lower water potential towards the adjacent cells
- water diffuse from neighbouring cells to spongy mesophyll cells via osmosis
- this movement produce transpirational pull
- water is pulled from xylem vessel to the outside of leaves
6
Q
definition of guttation
A
- secretion of water droplet
- through a special structure at the end of leave vein
- without involving stomata
- caused by high root pressure
7
Q
condition cause root pressure to happen
A
- high root pressure
- low transpiration rate
- high air humidity
- low temperature
8
Q
effect without guttation
A
- effective root pressure cannot be maintained
- water absorption of root hair cell is disrupted
- plant waste cannot be eliminated
- high leaf vein pressure
- leaf vein burst
- leaves exposed to pathogen
- eventually fall
9
Q
effect without transpiration
A
- optimum temperature cannot be maintained
- increase in temperature cause enzyme to denature
- disrupt biochemical process
- minerals ions cannot be transported to leaves for photosynthesis
- water transportation disrupt
- plant wilt and die
10
Q
definition of translocation
A
- process of transporting organic substances in the phloem
- from leaves to other parts of plant
11
Q
process of translocatin
A
- sucrose actively transported from leaves to sive tube through companion cells
- this reduce the water potential in sieve tube
- water diffuse from xylem into sieve tube via osmosis
- hydrostatic pressure in sieve tube increase
- high pressure cause phloem sap to be pushed along the sieve tube to other organs via active transport
- high water potential in phloem cause water diffuse and return to xylem via osmosis
- water pull by transpirational pull along the xylem against the direction of gravitational froce
12
Q
definition of phytoremediation
A
- treatment by using plants
- for the purpose of degradation, extraction or elimination of pollute substances
- from soil to water
13
Q
uses of water hyacinth
A
- long roots
- accumulate heavy metals (copper, lead) in water
14
Q
uses of sunflower
A
- hyperaccumulator
- eliminate heavy metals (zinc, copper, lead)
- and radioactive substances (caesium, strontium)
15
Q
uses of water lettuce
A
- fast growth rate
- treat waste water
- accumulate heavy metals
- absorb nutrients
