Top 25+ Transport in Plants - Biology Questions and Answers For NEET 2024 Exam Preparation

Q1. Consider the following statements

1. In active transport, pumps are proteins that use energy for the transportation of molecules against the concentration gradient.
2. Carrier protein is very specific.
3. Transport rate reaches a maximum when all the active protein transporters are used and saturated.

1. None is correct
2. All are correct
3. (1) and (3) are correct
4. (2) and (3) are correct

Answer: (b)

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Q2. If the external solutions balance the osmotic pressure of cytoplasm, it is said to be

1. hypotonic
2. isotonic
3. atomic
4. hypertonic

Answer: (b)

Isotonic solution is the external solution which balances the osmotic pressure of the cytoplasm.

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Q3. The plants face water stress due to the use of excessive fertilizers because of

1. Endosmosis
2. Exosmosis
3. Imbibitions
4. None of these

Answer: (b)

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Q4. Rate of the respiration of a plant is measured in still air and then again in similar condition but with a fan blowing air over it. Rate of transpiration will be

1. greater second time
2. greater first time
3. equal both the times
4. None of these

Answer: (a)

Transpiration is faster in air movement.

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Q5. What mechanism explains the movement of sucrose from source to sink ?

1. Osmotic movement of water into the sucrose loaded sieve tube cells creating a higher hydrostatic pressure into the source than in the sink.
2. Evaporation of water and active transport of sucrose from sink.
3. Tension created by differences in hydrostatic pressure in the source and sink.
4. Active transport of sucrose through the sieve tube membranes driven by proton pump.

Answer: (a)

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Q6. Transpiration and root pressure cause water to rise in plants by

1. Pulling and pushing it respectively
2. Pulling it upward
3. Pushing it upward
4. Pushing and pulling it respectively

Answer: (a)

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Q7. Assertion: In apoplast, the water movement is through mass flow.

Reason: The apoplast does not provide any barrier to water movement.

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

Answer: (a)

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Q8. Which of the following is not a feature of active transport of solutes in plants ?

1. Occurs through membranes
2. Non-selective
3. Occurs against concentration gradient
4. Requires ATP

Answer: (b)

Active transport is highly selective process.

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Q9. What mechanism explains the movement of sucrose from source to sink?

1. Osmotic movement of water into the sucrose-loaded sieve-tube cells creating a higher hydrostatic pressure in the source than in the sink.
2. Evaporation of water and active transport of sucrose from the sink.
3. Tension created by the differences in hydrostatic pressure in the source and sink.
4. Active transport of sucrose through the sieve-tube members driven by proton pumps.

Answer: (a)

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Q10. Passive absorption of minerals depend on

1. metabolic inhibitor
2. temperature and metabolic inhibitor
3. temperature
4. humidity

Answer: (c)

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Q11. What will be the direction of movement of water, when solution A having water potential of –9 bars and another solution B of –4 bars is separated by a semi-permeable membrane?

1. A to B
2. B to A
3. Both directions
4. None

Answer: (b)

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Q12. When a plant undergoes senescence, the nutrients may be

1. withdrawn
2. exported
3. translocated
4. None of the above

Answer: (c)

Senescence is the programmed death of a plant. At the time of senescence, translocation of nutrients to different parts of the plant are withdrawn.

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Q13. Passive absorption of minerals depends on

1. metabolic inhibitor
2. temperature and metabolic inhibitor
3. temperature
4. humidity.

Answer: (c)

Rate of salt absorption increases when temperature increases but to a certain limit as salt absorption is inhibited at higher temperature because certain enzymes are not active at higher temperature and carriers are not synthesised.

These carriers are required for active transport of salts from outer space in inner space Rate of diffusion of ions and molecules increases at enhanced temperature due to their increased kinetic activity.

Thus passive salt absorption will increase.

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Q14. In a terrestrial habitat which of the following is affected by temperature and rainfall condition?

1. Transformation
2. Transpiration
3. Translocation
4. Thermodenaturation

Answer: (b)

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Q15. The movement of ions against the concentration gradient will be

1. diffusion
2. osmosis
3. active transport
4. all of the above.

Answer: (c)

Active transport involves movement of materials across the membrane against the concentration gradient of the solute particles. It requires energy in the form of ATP and carrier molecules.

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Q16. Sinks are related to

1. Stomata
2. Transport of minerals
3. Enzymes
4. Phytochrome

Answer: (b)

It is the long-distance movement of organic substances from the source or supply and (region of manufacture or storage) to the region of utilization or sink.

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Q17. The translocation of organic solutes in sieve tube members is supported by

1. P-proteins
2. root pressure and transpiration pull
3. cytoplasmic streaming
4. mass flow involving a carrier and ATP.

Answer: (c)

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Q18. Which is always negative (under natural condition)?

1. $Ψ_s$
2. $Ψ_w$ of solution
3. $Ψ_p$
4. $Ψ_p$ of solution

1. 1 only
2. 1, 2 only
3. 4 only
4. 3 only

Answer: (b)

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Q19. A protoplast is a cell:

1. Undergoing division
2. Without nucleus
3. Without cell wall
4. Without plasma membrane

Answer: (c)

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Q20. Which of the following shows the correct explanation of the given figures?

1. Cell “A” neither gain nor loses $H_{2}$O, Cell “B” will gain $H_{2}$O, Cell “C” will lose $H_{2}$O.
2. Cell “A” will lose $H_{2}$O, Cell “B” will gain $H_{2}$O, Cell“C” neither gain nor loses $H_{2}$O.
3. Cell “A” will gain, Cell “B” neither gain nor loses $H_{2}$O,Cell “C” lose $H_{2}$O.
4. Cell “A” will gain $H_{2}$O, Cell “B” will lose $H_{2}$O, Cell“C” neither gain nor loses $H_{2}$O.

Answer: (d)

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Q21. Bulk flow of substances over the longer distances through the vascular tissue is called

1. facilitated diffusion
2. simple diffusion
3. active transport
4. translocation

Answer: (d)

The movement of organic food or solute in soluble form, from one organ to another organ is called translocation of organic solutes. The process of translocation requires expenditure of metabolic energy and the solute moves at the rate of 100 cm/hr.

The translocation of solutes occurs in a mass along with cell sap through the sieve tubes from a region of higher turgor pressure to low turgor pressure (i.e, along a turgor pressure gradient).

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Q22. In terms of permeability, the cell wall and plasmalemma are

1. Both semi-permeable
2. Permeable and differentially permeable respectively
3. Semi-permeable and differentially permeable
4. Both differentially permeable

Answer: (b)

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Q23. Process of imbibition results in

1. decrease in the volume of imbibing and development of pressure.
2. increase in the volume of imbibing but without development of pressure.
3. no change in volume of imbibant but pressure develops.
4. increases in volume of imbibant and development of pressure.

Answer: (d)

The phenomenon of imbibition has three important characteristics i.e., increase in volume, production of heat and development of imbibitional pressure.

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Q24. Stomata of a plant open due to

1. influx of potassium ions
2. influx of calcium ions
3. efflux of potassium ions
4. influx of hydrogen ions

Answer: (a)

During day time, due to photosynthesis, malic acid forms, which breaks into $H^{+}$ and malate.

$H^{+}$ ions move out of guard cells and $K^{+}$ ions enter forming potassium malate which makes guard cells turgid and stomata opens.

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Q25. In rainy season, door gets swelled due to

1. diffusion
2. imbibition
3. transpiration
4. respiration

Answer: (b)

In rainy season, door gets swelled due to the phenomenon of imbibition. It is the process of absorption of water without forming a solution.

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