Substances that enter the living cells by facilitated diffusion are:

1. generally polar in nature

2. transported in the direction of the 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

phenomenon of

1. imbibition

2. endosmosis

3. capillarity

4. deplasmolysis.

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.

Stomata opens:

(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

(2) Transpiration

(3) Capillarity

(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.

The water logging capacity of garden soil will be determined by measuring the weight of 

(1) soil by adding water and humus

(2) water saturated soil then heating the soil till it is dry and then measuring the weight of soil

(3) soil by adding water, boimass and humus

(4) soil from different locations with biomass.

The modified equation for water potential is:

1. ${\mathrm{\Psi }}_{\mathrm{w}}=$ ${\mathrm{\Psi }}_{\mathrm{s}}$ $+$ ${\mathrm{\Psi }}_{\mathrm{p}}$

2. ${\mathrm{\Psi }}_{\mathrm{w}}$ $=$ ${\mathrm{\Psi }}_{\mathrm{s}}-{\mathrm{\Psi }}_{\mathrm{p}}$

3. ${\mathrm{\Psi }}_{\mathrm{w}}={\mathrm{\Psi }}_{\mathrm{s}}$

4. ${\mathrm{\Psi }}_{\mathrm{w}}={\mathrm{\Psi }}_{\mathrm{p}}-{\mathrm{\Psi }}_{\mathrm{s}}$