The rupture and fractionation do not usually occur in the water column in vessel/tracheids during the ascent of sap because of
1. lignified thick walls
2. cohesion and adhesion
3. weak gravitational pull
4. transpiration pull
Two cells A and B are contiguous. Cell A has osmotic pressure 10 atm, turgor pressure-7
atm and diffusion pressure deficit 3 atm. Cell B has osmotic pressure 8 atm, turgor
pressure 3 atm and diffusion pressure deficit 5 atm. The result will be
1. Movement of water from cell B to A
2. No movernent of water
3. Equilibrium between the two
4. Movement of water from cell A to B
Substances that enter living cell by facilitated diffusion are
1. generally polar in nature
2. transported in the direction of concentration gradient
3. transported with the help of carrier proteins
4. all of the above
Wooden doors swell up and get stuck during the rainy season. This is due to the
In plants, water moves from
1. less negative to more negative potential
2. more negative to less negative potential
3. same potentials
4. none of the above.
(1) in day time - for gaseous exchange
(2) in day time - no gaseous exchange
(3) in night time only - for gaseous exchange
(4) in night time only - no gaseous exchange
If turgor pressure becomes equal to the wall pressure, then
1. water leaves the cell
2. water enters the cell
3. no exchange of water takes place
4. solute goes from the cell into water.
Which of the following helps in ascent of sap?
(1) Root pressure
(4) All of these
What do A, B, C and D represent in the following figure?
(1) A : carrier protein, B : symport, C : uniport, D : antiport
(2) A : carrier protein, B : uniport, C : antiport, D : symport
(3) A : carrier protein, B : antiport, C : symport, D : uniport
(4) A : carrier protein, B : uniport, C : symport, D : antiport
What is correct about the movement of substances across the membrane in facilitated diffusion?
1. It is an active transport.
2. It causes the transport of molecules from low concentration to high concentration.
3. It is insensitive to inhibitors.
4. It is a very specific transport.