211.

In plants, water moves from

• less negative to more negative potentia

• more negative to less negative potential

• same potentials

• none of the above

Assertion : A plant girdled upto bast will die.

Reason : Food transportation in such plant will cease followed by ceasation of water transport.

• If both Assertion and Reason are true and Reason is the correct explantion of Assertion

• If both Assertion and Reason are true and Reason is not the correct explanation of Assertion

• If Assertion is true but Reason is false

• If Assertion is false but Reason is true

Choose the wrong statement

• Cells swell in hypertonic solutions and shrink in hypotonic solutions

• Water potential is the kinetic energy of water which helps in the movement of water

• The absorption of water by seeds and dry wood takes place by a special type of diffusion called imbibition

• Solute potential or PS is always negative

• Solute potential or PS is always negative

Which of these is/are not a property of facilitated transport?

(A) Requires special membrane proteins 

(B) Highly selective 

(C) Uphill transport 

(D) Requires ATP energy

• (A) and (B) only

• (C) and (D) only

• (A) and (C) only

• (B) and (C) only

• (B) and (C) only

Which of the following statements about the mass flow hypothesis is wrong?

• It is the accepted mechanism for translocation of sugars from source to sink

• As glucose is prepared at source it is converted to sucrose

• Sucrose is actively loaded into a sieve tube

• The process of loading at source produces a hypotonic condition in the phloem

• The process of loading at source produces a hypotonic condition in the phloem

Match the following and choose the correct option.

Column I	Column II
A. Water potential	i.  It is usually positive
B.  Solute potential	ii.  It is zero for pure water
C. Pressure potential	iii.  It is always negative

• A - ii; B - iii; C - i

• A - i; B - iii; C - ii

• A - iii; B - ii; C - i

• A - ii; B - i; C - iii

• A - ii; B - i; C - iii

Which of the following statements about plasmolysis is/ are true?

I . Plasmolysis occurs when water moves into the cell.

II. Cells shrink in hypotonic solutions.

III. If the external solution balances the osmotic pressure of the cytoplasm, it is said to be isotonic.

• I only

• II only

• III only

• I and II only

• I and II only

When a molecule moves across a membrane independent of other molecules the process is called

(i) Uniport

(ii) Symport

(iii) Antiport

• (i) only

• (i) and (ii) only

• (i) and (iii) only

• (ii) and (iii) only

• (ii) and (iii) only

Apopalstic movement of water occurs exclusively through the

(i) Intercelluar spaces

(ii) Walls of the cells

(iii) Plasmodesmata

(iv) Cytoplasm

• (i), (ii) and (iv) only

• (iii) and (iv) only

• (i) and (ii) only

• (ii) and (iv) only

• (ii) and (iv) only

Grass leaves curl inwards during very dry weather. Select the most appropriate reason from the following

• flaccidity of buliform cells

• shrinkage of air spaces in spongy mesophyll

• tyloses in vessels

• closure of stomata