Prepare for NEET Biology Transport in Plants with MCQs & PYQs on NEET.GUIDE. Access free practice, previous year questions, and expert guidance to understand xylem, phloem, and movement of water.
Certain integral membrane proteins facilitate the diffusion of molecules across the membrane without directly binding to the transported molecule. These proteins create a continuous aqueous pathway through the lipid bilayer. Which of the following is the BEST example of such facilitated diffusion?
GLUT transporters moving glucose
Sodium-potassium pump maintaining ion gradients
Aquaporins transporting water
Chloride channels gated by voltage
Which characteristic distinguishes facilitated diffusion from simple diffusion across a biological membrane?
Movement down a concentration gradient
Specificity for the transported molecule
Passive transport requiring no energy input
Dependence on membrane fluidity
Which of the following statements regarding facilitated diffusion is INCORRECT?
It requires transport proteins.
It is a passive process and does not require energy.
It can move molecules against their concentration gradient.
Transport proteins involved can become saturated.
Facilitated diffusion differs from simple diffusion in that:
Facilitated diffusion requires membrane proteins, while simple diffusion does not.
Facilitated diffusion moves substances against their concentration gradient, while simple diffusion moves them down their concentration gradient.
Facilitated diffusion requires energy expenditure, while simple diffusion does not.
Facilitated diffusion occurs only in plant cells, while simple diffusion occurs in all cells.
Two solutions, A and B, are separated by a selectively permeable membrane. Solution A contains 10% sucrose, and Solution B contains 20% sucrose. In which direction will the net movement of water occur?
From Solution A to Solution B
From Solution B to Solution A
There will be no net movement of water.
The sucrose will move from Solution B to Solution A.
Which of the following is NOT a factor affecting the rate of osmosis?
The concentration gradient of water across the membrane
The temperature of the solutions
The permeability of the membrane to water
The amount of solute that can dissolve in the solvent
A plant exposed to a fungal toxin exhibits significantly reduced translocation of potassium ions () despite normal transpiration rates. The toxin MOST likely affects which process?
Stomatal opening and closing
Water potential gradient in the xylem
Activity of membrane transport proteins involved in uptake into xylem
Root pressure generation
Facilitated diffusion does not require/show
Special membrane proteins
Saturation of transport
ATP energy
Selective nature
If two molecules A & B move in the same direction. This movement can be called
Antiport
Symport
Uniport
Guttation
If two molecules A & B move in the same direction. This movement can be called
Antiport
Symport
Uniport
Guttation
