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

Ascent of sap can be explained by _______ experiment

  1. Thistle-funnel

  2. Potato osmoscope

  3. Ringing

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

The ringing experiment (girdling) involves removing a ring of bark (phloem) from a plant stem while leaving the xylem intact. This demonstrates that organic nutrients (sugars) are transported through the phloem, as food accumulates above the ringed portion, causing swelling. The ringing experiment proves the existence and direction of phloem transport (translocation), which is part of the sap ascent mechanism.

Multiple choice

Deficiency of Nitrogen causes

  1. premature leaf fall

  2. chlorosis of leaves

  3. necrosis of stem

  4. chlorosis in veins
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Nitrogen deficiency causes chlorosis - the yellowing of leaves due to insufficient chlorophyll production. Nitrogen is a crucial component of chlorophyll molecules and amino acids.

Multiple choice

Abscission in a plant is the

  1. wilting and falling of leaves

  2. opening of stomata

  3. elongation of shoots

  4. fruit growth

  5. phototropic and geotropic responses of the plant
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct option.

Multiple choice

Hygroscopic water is attached to the soil particle by means of a force called

  1. Osmosis

  2. Diffusion

  3. Capillarity

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

Hygroscopic water is held as a thin film around soil particles by imbibition forces - the attraction between water molecules and colloidal soil particles. It's so tightly held that plants cannot absorb it. Osmosis and diffusion are water movement processes, not attachment forces. Capillarity is water movement in narrow spaces due to surface tension.

Multiple choice

Which of the following statements is incorrect?

  1. All parts of a plant perform respiration individually.

  2. Roots of plants take oxygen required for respiration through diffusion.

  3. Oxygen diffuses in root hair and transports to other cells for respiration.

  4. Roots of a land plant respire anaerobically.

  5. There is little transport of respiratory gases during respiration in plants.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the correct answer as this statement is incorrect.

Multiple choice

How do small plants grow into a tree?

  1. Increase in cell size

  2. Increase in cell number

  3. Increase in cell diameter

  4. Increase in cell height
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Plants grow primarily through cell division (mitosis) in meristematic tissues, which increases cell number. While individual cells do expand (increase in size), the fundamental growth mechanism is the production of more cells through cell division.

Multiple choice

Respiratory quotient in succulents is

  1. one

  2. more than one

  3. less than one

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

 Respiratory quotient in succulents is more than one as organic acids form the respiratory substrate.

Multiple choice

The processes of apostrophe and epistrophe are associated with

  1. chemotectic movement

  2. thermotectic movement

  3. phototectic movement

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

The processes of apostrophe and epistrophe are associated with phototectic movement. They are movements of chloroplasts in bright and weak light.

Multiple choice

What happens in thigmotropism movement?

  1. Movement of curvature, in which a plant organ, i.e. roots, turn away from water current

  2. The movement of plants, in response to touch or physical contact

  3. Plant movement in response to one sided injury

  4. Plant movement, in which the organs of plants track the sun across the sky
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The movement of plants in response to touch or physical contact is known as thigmotropism.

Multiple choice

Which movement is found only in dead parts of the plants?

  1. Nyctinastic movement

  2. Geotropic movement

  3. Hydrotropic movement

  4. Hygroscopic movement
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hygroscopic movement is found only in dead parts of the plants, which are hygroscopic in nature and result either due to loss or gain of water by them from the atmosphere.