Biology

Plant Transport and Physiology

1,834 Questions

Access a comprehensive set of questions on plant transport mechanisms and physiological adaptations. Topics include water movement, translocation of food, and plant responses to external stimuli. These biology questions are essential for medical entrance exams and other science competitive tests.

Xylem and phloem transportTranspiration and evaporationPlant adaptationsGeotropic and phototropic responsesWater absorption by rootsRespiration in roots

Plant Transport and Physiology Questions

Multiple choice

In plants, bulk flow is the movement of substances in bulk or en masse from one point to another. In which of the following ways can it be achieved?

a. Positive hydrostatic pressure gradient b. Negative hydrostatic pressure gradient c. Positive concentration gradient

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is the correct option. Bulk flow can be achieved either through a positive hydrostatic pressure gradient or a negative hydrostatic pressure gradient.

Multiple choice

Transpiration is the evaporative loss of water by plants. Which of the following is not a function of transpiration?

  1. It supplies water for photosynthesis.

  2. It transports minerals from the leaves to the other parts of the plant.

  3. It maintains the structure of the plants.

  4. It keeps the surfaces of leaves cool.

  5. It creates transpiration pull.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is the correct option as this is not a function of transpiration. It transports minerals from the soil to all parts of the plant.

Multiple choice

Which of the following statements is/are false?

a. Transpiration is the evaporative loss of water by plants through the stomata in the leaves. b. Pinus seeds cannot germinate and establish without the presence of mycorrhizae. c. The inner wall of each guard cell is thin and non-elastic.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct option as this statement is false. The inner wall of each guard cell is thick and elastic.

Multiple choice

Which of the following is the function of phloem?

  1. It transports food.

  2. It helps in opening and closing of stomata.

  3. It transports water.

  4. It is responsible for the protection of plant.

  5. It prevents the wilting of plants.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Transporting food is the function of phloem.

Multiple choice

'Stomata' are useful for

  1. exchange of gases and transpiration

  2. conducting water and dissolved minerals to different parts of the plant

  3. conducting prepared food from green leaves to other parts of the plant

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Stomata are microscopic pores primarily found on leaf surfaces that serve two critical functions: gas exchange (CO2 intake for photosynthesis, O2 release) and transpiration (water vapor loss). Option B describes xylem function, and option C describes phloem function. Stomata open and close via guard cells to balance these processes.

Multiple choice

Cork becomes impervious to water by the deposition of

  1. suberin

  2. lignin

  3. chitin

  4. pectin

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

At maturity the cork cells are nonliving, and their inner walls are lined with suberin, a fatty substance that is highly impermeable to gases and water (which is why cork is used to stop wine bottles). The walls of cork cells may also contain lignin.

Multiple choice

How is water loss reduced in desert plants?

  1. Thick sclerenchymatous layer over epidermis of leaves prevents water loss.

  2. The outermost surface of epidermis secretes suberin, which is waterproof.

  3. Cutin secreted by the outermost surface of epidermis is waterproof.

  4. Leaves of such plants secrete oil to prevent water loss.

  5. The outermost surface of epidermis secretes lignin, which is waterproof.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cutin helps in reduction of water loss in desert plants as it is waxy and water-resistant.

Multiple choice

Which of the following statements is incorrect?

  1. Root cells create a difference in ionic concentration between roots and soil.

  2. Water is steadily pushed upwards from soil.

  3. Evaporation of water molecules for plants surface helps in upward movement of water.

  4. Water from the roots is not transported through root pressure at night.
Reveal answer Fill a bubble to check yourself
D Correct answer
Multiple choice

Water in the plants is transported by the tissue called

  1. phloem

  2. xylem

  3. leaves

  4. parenchyma
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Xylem is the vascular tissue responsible for transporting water and dissolved minerals from roots to all parts of the plant. It consists of dead, hollow cells (tracheids and vessels) that form continuous tubes for water movement. Phloem transports organic nutrients (sugars) in the opposite direction.

Multiple choice

How is transpiration important for a plant?

  1. It helps in absorption of minerals.

  2. It helps to regulate temperature.

  3. It is major driving force in movement of water in xylem.

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Transpiration serves multiple functions: it creates the transpiration pull that drives water movement through xylem, it helps cool leaves through evaporative cooling, and it aids in mineral absorption by maintaining water flow through roots. All three options are valid functions, making 'All of the above' the correct choice.