Transport In Plants Flashcards
Transport of water through xylem is unidirectional or multidirectional?
Unidirectional
Transport through Phloem is unidirectional or multidirectional
Multidirectional
Transport through vascular system is called
Translocation
State the features of simple diffusion
Simple diffusion is random , Slow, passive and not dependent on system in which it is occurring
Highest concentration of oxygen in a leaf is present in
Lumen of thylakoids
Why is diffusion very important for plants
Because it is the only means for gaseous movement within plant body
State the features of facilitated diffusion
Facilitated diffusion is passive, downhill transport, helped by channel and allows movement of hydrophilic substances
State three features of channel
Selective, saturation and inhibition
What are inhibitors
Inhibitors are chemicals that can bind with protein side chain and can change the shape of channel
Porins are located on
Mitochondria, plastids and some bacteria (gram -ve)
Water channels are made up of
8 different types of Aqua Porins
The process in which molecule moves across the membrane independent of other molecules is
Uniport
State the features of active transport
Uphill transport, active and occur with the help of pump made up of protein
Cytoplasmic streaming is active or passive?
Active process
State the direction of movement of water with respect to water potential
High water potential to lower water potential
On adding Solute, solute potential ??
Decreases
State the direction of movement of water with respect to solute potential
High solute potential to lower solute potential
Water potential is a concept fundamental to understanding
Water movement
Water potential of pure water at standard temperature which is not under any pressure is taken to be
Zero
What is tonoplast
Tonoplast is lipid bilayer of vacuole
State the movement of water with respect to Osmotic pressure
Low osmotic pressure to high osmotic pressure
Vacuole is …………… as compared to cytoplasm
Hypertonic
What is protoplast
Cytoplasm + plasma membrane
State the value of turgor pressure in flaccid, turgid and plasmolysed cell
Turgor pressure is zero in flaccid cell, positive in turgid cell and negative in plasmolysed cell
During plasmolysis water is first lost from ………… and then from …………
Cytoplasm, vacuole
Order of occurrence of imbibition
Agar agar > pectin > protein > starch > cellulose
On adding solute, diffusion pressure(DP)…………
Decreases
On adding solute, diffusion pressure deficit (DPD)……………
Increases
Formula for DPD is ??
DPD=OP-TP
State one dissimilarity between mass flow and diffusion
In mass flow substances whether in solution or in suspension are swept along at the same pace while in diffusion substances move independently depending on their concentration gradient
Water in roots is always absorbed
Passively
Mineral absorption is
Both active and passive (mostly active)
Mineral is always absorbed in …… form
Ionic
Water potential is affected by:
(a) Solute concentration
(b) Pressure
(c) Temperature
(d) All of these
(d)
Pressure can build up in a plant system when water enters a plant cell due to diffusion causing a pressure built up against the cell wall, it makes the cell turgid this increases
the:
(a) Solute potential
(b) Pressure potential
(c) Water potential
(d) Both (a) and (b)
(b)
The translocation of organic solutes in sieve tube members is supported by
Mass flow involving a carrier and ATP
Glycolate induces opening of stomata in
Low CO2 concentration
Example of a plant in which sunken stomata are found
Nerium
The direction and rate of water movement from Cell to cell is based on
Diffusion pressure deficit
In guard cells when sugar is converted into starch the stomatal pore
Close completely
Girdling experiment cannot be performed within sugarcane because
Vascular bundles are not present in a ring
Spraying of phenyl mercuric Acetate in leaves _____________ transpiration
Reduces
Root pressure develops due to
Active absorption
