Biology

Plant Transport and Physiology

2,012 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

Where is casparian strip located?

  1. In epidermis

  2. In hypodermis

  3. In cortex

  4. In endodermis
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Casparian strip is located in endodermis. It blocks the passive flow of materials, such as water and solutes into the stele of a plant.

Multiple choice

Plants can synthesise their own food by

  1. transpiration

  2. evaporation

  3. photosynthesis

  4. precipitation

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

Photosynthesis is the biological process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water.

Multiple choice

Abscisic acid causes

  1. slow movement of water out of the guard cells

  2. slow movement of K+ out of the guard cells

  3. rapid movement of water out of the guard cells

  4. rapid movement of K+ out of the guard cells
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Abscisic acid (ABA) acts as a stress hormone that triggers stomatal closure. It does this by inhibiting H+ pumps and promoting the rapid efflux of K+ ions from guard cells, which leads to water loss and turgor reduction.

Multiple choice

Stomata of CAM plants

  1. open during the night and close during the day

  2. never open

  3. are always open

  4. open during the day and close at night
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

CAM (Crassulacean Acid Metabolism) plants keep their stomata closed during the day to minimize water loss in arid environments and open them at night to take in CO2.

Multiple choice

The pigment essential for N2 fixation by leguminous plants is

  1. phycocyanin

  2. anthocyanin

  3. leghemoglobin

  4. phycoerythrin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Leghemoglobin is an oxygen-binding protein found in the root nodules of leguminous plants. It maintains low oxygen levels to protect the oxygen-sensitive nitrogenase enzyme.

Multiple choice

Maximum transpiration occurs from

  1. dermal tissue

  2. ground tissues of scale leaves

  3. periderm and lenticels

  4. protoderm and procambium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Stomatal transpiration, which occurs through the stomata located in the dermal tissue (epidermis) of leaves, accounts for the vast majority of water loss in plants.

Multiple choice

Chlorosis occurs due to the

  1. deficiency of light

  2. deficiency of Mg and Fe

  3. deficiency of pigments in the soil

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

Chlorosis is the yellowing of leaves due to a lack of chlorophyll. Magnesium is a central atom in the chlorophyll molecule, and iron is required for its synthesis, so their deficiency leads to chlorosis.

Multiple choice

Most widely accepted explanation for the ascent of sap in plant is

  1. capillarity / Imbibition

  2. pulsating activity of living cells

  3. role of atmospheric pressure

  4. transpiration-cohesion theory
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The transpiration-cohesion-tension theory is the most widely accepted explanation for how water moves upward through the xylem against gravity. It relies on the cohesive properties of water and the pull generated by transpiration.