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
Phloem sap is mainly:
1. Glucose and Water
2. Hormones and Amino acids
3. Water and Sucrose
4. Amino acids and water
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 sec 11.4, NCERT, it is mentioned that transpiration is affected by the canopy structure. This means that transpirational loss is lower in shaded leaves compared to sun exposed leaves higher in canopy. What would not be a reason for this?
1. Lower stomatal conductance
2. Lower leaf temperature
3. Lower air humidity
4. Lower air turbulence
Based on your knowledge about root pressure given in section 11.3.2.1 , NCERT, can you think which of the following will play the most important role in development?
1. Epidermal hair
2. Endodermis
3. Cortex cells
4. Pericycle
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.