Which of the following will not cause the stomata to close?
wilting
increase in carbon dioxide concentration
darkness
increase in pH
Pick the incorrect statement
Guard cells help balance the photosynthesis-transpiration compromise.
Water tension in a transpiring plant will exert a pull on water molecules lower down in the plant's vascular system.
Plants that live in deserts have adapted to constant water stress by using hydrophilic colloids to increase the water potential of their tissues.
C3 plants can fix double the carbon dioxide for half the water transpired.
What seems to be the most valid statement about root pressure?
It is the positive pressure responsible for transport of water most commonly.
It may provide a considerable push to the water column during transport.
It may help re establish the broken water columns during transpiration
Its effect is most observable during mid day
A structural attribute of guard cells that aid in its effective functioning is
Large cell size
Radial micellation in walls
Thick walls
All of the above
Not an aid to water absorption is
The high surface area of roots
High water potential of root hair cells
Thin cellulosic walls of root hair zone
Low concentration of solutes in the soil
The water is free to move between the cells except through the
xylem
epidermis
endodermis
pericycle
Continuity of protoplasm in sieve elements is maintained through
Cytoplasmic strands
P proteins
Vacuoles
Walls
Which is not an advantage of transpiration.
Maintains shape of cells by keeping them turgid
Cools down plant surfaces by evaporative cooling
Transports minerals.
None of the above.
One of the following is not a pre-requisite for transpiration?
high Vapour pressure deficit of atmosphere
Low atmospheric humidity
High soil water potential
Sunny weather
A manifestation of root pressure is
Guttation
transpiration
Cohesion
Negative hydrostatic pressure
What is not a part of symplast?
Cell membrane
Cell wall
Tonoplast
Plasmodesmata
Mass flow seems to be the prominent mode of transport during
Translocation of organic solutes within phloem.
traslocation of water and minerals in xylem
Apolplastic movement of water in plants
What is not a part of apoplast?
Intercellular spaces
Cell Walls
Sieve tubes
Vessels
Which is not an example of imbibition
Raisins soaked in water
Wheat grains soaked in water
Gram seeds soaked in water
A piece of wood soaked in water.
When the cell is flaccid
Inflow and outflow of water is in equilibrium
Turgor pressure of the cell is 0
placed in isotonic solution
All of the above.
When a cell is plasmolysed what lies between the cellwall and the cell membrane?
Water
Air
Nothing
Hypertonic solution
A value that is always negative in a cell is
Solute potential
Osmotic pressure
pressure potential
DPD
The main difference between active and passive transport across cell membrane is :
passive transport is non-selective whereas active transport is selective
passive transport requires a concentration gradient across a biological membrane whereas active transport requires energy to move solutes.
passive transport is confined to anionic carrier proteins whereas active transport is confined to cationic channel.
active transport occurs more rapidly than passive
Which of the following is not a feature of active transport of solutes in plants ?
Occurs against concentration gradient
Non-selective
Occurs through membranes
Requires ATP
What will be the direction of flow of water when a plant cell is placed in a Hypotonic solution?
Water will flow in both directions.
Water will flow out of the cell.
Water will flow into the cell.
No flow of water in any direction.
The process responsible for facilitating loss of water in liquid form from the tip of grass blades at night and early morning is:
Root pressure
Imbibition
Plasmolysis
Transpiration
Match List - I with List-II.
(i) More attraction in liquid phase (ii)Mutual attraction among water molecules (iii)Water loss in liquid phase(iv) Attraction towards polar surfaces
Choose the correct answer from the options given below.
(a) (b) (c) (d)
(iii) (i) (iv) (ii)
(ii) (i) (iv) (iii)
(ii) (iv) (i) (iii)
(iv) (iii) (ii) (i)
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