Loading of phloem is related to:
1.  Increase of sugar in phloem
2.  Elongation of phloem cell
3.  Separation of phloem parenchyma
4.  Strengthening of phloem fiber

The most abundant solute in the phloem sap is :
1. Potassium ions
2. Sucrose
3. Glucose
4. Starch

Continuity of protoplasm in sieve elements is maintained through

1. Cytoplasmic strands

2. P proteins

3. Vacuoles

4. Walls

Mass flow seems to be the prominent mode of transport during

1. Translocation of organic solutes within phloem.

2. translocation of water and minerals in xylem

3. Apolplastic movement of water in plants

4. All of the above

Consider the following two statements:

I. The direction of movement in the phloem is bi-directional.

II. The source-sink relationship in plants is variable.

1. Both I and II are correct and II explains I

2. Both I and II are correct but II does not explain I

3. I is correct but II is incorrect

4. Both I and II are incorrect 

During translocation of sugars in plants from source to sink:

1. The loading of sugar at source is by active transport and unloading at the sink is by passive transport.

2. The loading of sugar at source is by passive transport and unloading at the sink is by active transport.

3. Both loading at the source and unloading at the sink are by active transport.

4. Both loading at the source and unloading at the sink are by passive transport.

Phloem sap is mainly:-

1.  Water and osmotically inactive disaccharides only

2.  Water and PGRs only

3.  Water and osmotically active disaccharides 

4.  Minerals and PGRs only

According to the mass flow hypothesis:
(a) Sucrose is moved into the companion cells and then into the sieve tube by passive transport.
(b) Inside the phloem, an osmotic pressure gradient is generated that facilitates the mass movement in the phloem.
(c) Water in the adjacent xylem moves into the phloem by an active process.

1. (a) and (c) are correct.
2. (b) and (c) are incorrect.
3. (a) and (c) are incorrect.
4. (a) and (b) are correct.

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)

Function of companion cells is: