What are the control points where a plant adjusts the quantity and types of solutes that reach the xylem?
1. Cellulose deposited casparian strips
2. Transport proteins of endodermal cell
3. Sclerenchyma around the pericycle
4. The root hairs themselves
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.
During plasmolysis:
1. Water is lost from the cytoplasm but not from the vacuole
2. Water is first lost from the cytoplasm and then from the vacuole
3. Water is first lost from the vacuole and then from the cytoplasm
4. Water is lost from the vacuole but not from the cytoplasm
The smallest amount of pressure needed to stop fluid from moving by osmosis is referred to as the
1. Turgor pressure
2. Water potential
3. Pressure potential
4. Osmotic pressure
What is the first step in the germination of a seed?
1. pollination
2. fertilization
3. imbibition
4. hydrolysis of starch and other food reserves
Consider the following:
I. A decrease in pressure on cell exerted by the wall
II. An increase in water potential of the surroundings
III. The uptake of solutes by the cell
IV. An increase in the tension on the surrounding solution
Which of the above would contribute to the uptake of water by the cell?
1. I, II, III
2. II, III, IV
3. I, II, IV
4. I, III, IV
What is true for both symplast and apoplast movement of water in plants?
1. An equal rate of transport
2. Being down a potential gradient
3. Assistance by cytoplasmic streaming
4. Conduction through interconnected protoplasts
Pressure on a plant cell wall caused osmotic movement of water is called:
1. Osmotic pressure
2. Osmotic potential
3. Turgor pressure
4. Hypertonic pressure
The most abundant solute in the phloem sap is :
1. Potassium ions
2. Sucrose
3. Glucose
4. Starch