How many of the following statements are correct?
(i) In plants each organ receiving some substances & giving out some others.
(ii) Water channels are made up of eight different types of aquaporins.
(iii) Water is often a limiting factor for plant growth & productivity in both agricultural & Natural environments.
(iv) Imbibition is also diffusion.

Options:
1. All the above
2. (i), (ii) & (iv)
3. (ii), (iii) & (iv)
4. (iii) & (iv)

In the xylem, a continuous chain of water, when it is broken, is re-established by:
1. Guttation
2. Root pressure
3. Imbibition
4. Transpiration

The interconnected cells which do not show symplastic movement of water are:

1. Mesophyll cells
2. Tracheids
3. Xylem parenchyma cells
4. Cells of endodermis

The water potential of pure water at standard temperatures, which is not under any pressure is taken to be equivalent to
1. Zero
2. –${\mathrm{\psi }}_{\mathrm{S}}$
3. ${\mathrm{\psi }}_P$
4. +${\mathrm{\psi }}_{\mathrm{S}}$

Select incorrect statement(s):
(a) Both phloem loading and unloading are active processes.
(b) Loading of the phloem sets up root pressure that facilitates the mass movement in the phloem.
(c) As the hydrostatic pressure in the phloem sieve tube increases, pressure flow begins and the sap moves through
the phloem.

1. Both (b) & (c)
2. Both (a) & (c)
3. Only (b)
4. Only (c)

Which of the following is not a feature of the active transport of solutes in plants?

1. Occurs against the concentration gradient

2. Non-selective

3. Occurs through membranes

4. Requires ATP

What will be the direction of flow of water when a plant cell is placed in a Hypotonic solution?

1. Water will flow in both directions.

2. Water will flow out of the cell.

3. Water will flow into the cell.

4. No flow of water in any direction.

I. Phloem sap can be transported in any required direction.
II. Phloem transports mainly water and sucrose but other sugars, hormones, and amino acids are also transported.
III. Cytoplasmic strands pass through the holes in the sieve plate forming continuous filaments.
IV. Ascent of sap is a pulling movement and the translocation of organic solutes is a pushing movement.

1. All are correct
2. All are incorrect
3. I, II, III are correct
4. III and IV are correct

The incorrect statement for facilitated diffusion is:

1. Special proteins help move substances across membranes without the expenditure of energy.

2. Can cause net transport of molecules from a low to a high concentration.

3. It is very specific, it allows cells to select substances for uptake.

4. Transport rate reaches a maximum when all of the protein transporters are being used.

When a cell is placed in a solution whose osmotic concentration is equal to cell sap then:

1. Water moves inside the cell.

2. Water moves outside the cell.

3. No net movement of water occurs.

4. Cell will be plasmolysed.