Osmotic pressure of a solution is
1. more than that of pure solvent
2. less than that of pure solvent
3. variable depending upon concentration
4. equal to that of pure solvent
The continuous excretion of watery substance
from stump of a well-watered potted plant after
cutting off the shoot slightly above the base is
due to
1. root pressure
2. guttation
3. transpiration
4. imbibitions
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.
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
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. –
3.
4. +
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