The control points where a plant adjusts the quality and types of solutes that reach the xylem are:

1. Transport proteins of endodermal cells	2. Root hair
3. Parenchyma cells of the root cortex	4. Casparian strips

Unloading of mineral ions occurs at the fine vein endings through:
1. diffusion and, are passively taken up by the sink cells
2. active transport and, are passively taken up by the sink cells
3. diffusion and, are actively taken up by the sink cells
4. active transport and, are actively taken up by the sink cells

An analysis of xylem exudates will show that most of the nitrogen is carried as:
1. Inorganic ions
2. Ammonia dissolved in water
3. Dinitrogen
4. Organic compounds such as amino acids

Unlike xylem, the movement of sap in phloem is:
1. essentially unidirectional
2. from a sink to a source
3. independent of movement of water
4. in any direction from source to a sink

During mass flow in phloem, active transport is required:
1. For uploading sap
2. For unloading sap
3. Both for uploading and unloading the sap
4. Active transport is not required

Refer section 11.3.1, NCERT where it is stated that most of the water flow in the roots occurs via the apoplast. Why is this so?
1. Endodermis has suberized casparian strips
2. Root cortex cell lack plasmodesmata
3. Cortical cells are loosely packed
4. Root cortex is poorly organized

In section 11.1.2, NCERT states that a concentration gradient needs to be present in spite of the fact that facilitated diffusion is facilitated by a carrier. Why is it so?
1. These protein carriers have ATPase activity.
2. These protein carriers can not move in the membrane.
3. These protein carriers can not establish concentration gradients.
4. These protein carriers can provide only symport with the use of external energy.

 Consider the following statements with respect to the relationship between osmotic pressure and osmotic potential as explained in section 11.2.2 in NCERT
I. Water moves from regions of higher osmotic pressure to regions of lower pressure
II. Osmotic potential is equivalent to osmotic pressure in concept but opposite in sign
The correct statements are:
1. I only
2. II only
3. Both I and II
4. None

Refer section 11.1.1 of your NCERT. What peculiarity does NCERT mention regarding diffusion and solids ?
1. It does not occur in solids
2. It is more easily visualized in solids
3. It requires expenditure of external energy and occurs against concentration gradient
4. Diffusion in solids rather than of solids is more likely.

Which one of the following will not directly affect transpiration?