Assertion: Phloem sap moves form sugar source to sugar sink.
Reason: A storage organ, such as a tuber or bulb, may be a source or a sink, depending on the season.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
3. If the assertion is true but the reason is false
4. If both the assertion and reason are false

Assertion: The concentration of free sugar in the sink is always lower than in the sieve tube.
Reason: The unloaded sugar is consumed during growth or metabolism or converted to insoluble polymers such as starch.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: Removing sinks is a useful horticulture practice such as in production of larger sized apples.
Reason: If sinks are more than the source can support, plants may undergo self-thinning.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Diffusion:
I. does not require any energy expenditure
II. is dependent on a living system
III. is a fast process
IV. is the only means for gaseous movements in plants
1. Only I and IV are correct
2. Only I, II and IV are correct
3. Only I, III and IV are correct
4. Only II and III are correct

Substances that have a hydrophilic moiety:
1. have to be transported across the plasma membrane by active transport
2. can diffuse across the plasma membrane at a slower rate, if larger in size
3. do not need a concentration gradient to diffuse across the plasma membrane
4. need to be facilitated even along the concentration gradient

Facilitated diffusion allows cells to:
1. achieve uphill transport without ATP energy
2. select substances for uptake
3. stop transport of hydrophilic substances
4. decrease the rate of diffusion of lipophilic substances

In gram negative bacteria the outer membrane:
1. is the major permeability barrier
2. is a thick peptidoglycan layer
3. is more permeable to hydrophilic substances
4. is devoid of lipopolysaccharides

Unlike a symporter and an antiporter, a uniporter:
1. is not an integral membrane protein
2. is a cell surface carbohydrate
3. is not a co-transporter
4. cannot be used for active transport

What differentiates active transport from facilitated diffusion?
I. Uphill transport
II. Requirement of special membrane proteins
III. Selective nature
1. Only I
2. Only I and II
3. Only I and III
4. Only II and III

Consider the following statements:

Correct statements are:
1. I and II
2. I and III
3. II and III
4. I, II and III