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 biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

Transporting pull arise mainly from

  1. Roots

  2. Leaves

  3. Stems

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

As water is lost from the surface of the leaves due to transpiration a strong suction force is transmitted through the active mesophyll cells to the ends of the water column in the root. This is called transpiration pull. It caused the entire water column to be pulled upwards. When the rate of transpiration is very high and the rate of absorption is slow the water in the xylem elements of the leaf develops a state of tension.

So, the correct answer is B.

Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

Which of the following does not operate in the carrier concept of active absorption of minerals?

  1. Electron transport

  2. Contractile protein

  3. Protein lecithin

  4. Ascending water stream
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Plants absorb minerals from the soil in the form of inorganic ions. The process of mineral absorption and water absorption are separate processes occur in plants. Water absorption takes place actively by root pressure whereas mineral absorption takes place actively with the help of carrier proteins.
So the correct answer is 'Ascending water stream'.
Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

Mineral absorption is mostly

  1. Physical process

  2. Chemical process

  3. Active process

  4. Passive process
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Mineral absorption takes place in two phases: active absorption and passive absorption. It mostly occurs using active absorption phase because it is a fast process of mineral absorption, utilise energy and unidirectional. It is a biochemical process that occurs against the concentration gradient with the help of carriers and pumps.
So the correct answer is 'Active process'.
Multiple choice botany know the plant world closely nutrition and its types types of nutrition in plants different modes of nutrition in plants

Parasitic phanerogams absorb water and solute from host plant by

  1. Mycorrhiza

  2. Clinging roots

  3. Adventitious roots

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

Parasitic plants are those which depend on other plants for their food either completely or incompletely. These plants produce a special organ called haustorium which produce adventitious roots to absorb food and nutrients.

So the correct option is D.

Multiple choice biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

Which of the following is an important feature of roots which help them to absorb water and minerals from the soil?

  1. Roots provide very less surface area

  2. Cells of root contain cell sap

  3. Root hairs have thick walls

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

Larger surface area and thinner walls of root hair are required to absorb water efficiently. 

Cells of the root contain sap which has an accumulation of ions which significantly reduces the water potential. Hence water enters the cells from the soil passively. 
So the correct answer is ' Cells of root contain cell sap'. 

Multiple choice biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

The cells of the roots contain cell sap at a .................. concentration than that of surrounding soil water.

  1. Higher

  2. Lower

  3. Equal

  4. All of the following
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The cells of the roots contain cell sap (solution) at a higher concentration than that of surrounding soil water. As a result, the water is absorbed by the root hairs. This is because the water always travels from a region of high water potential to the region of lower water potential. Here, the soil possesses a higher water potential as compared to the root hair.

Multiple choice biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

Rupture and fractionation of water column present in tracheary elements does not occur during ascent of sap due to

  1. Transpiration pull

  2. Weak gravitational pull

  3. Cohesion and adhesion

  4. Lignified thick walls
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Transpiratioal or gravitational pull exert strain so they are factors that can cause rupture of the column. 

Lignified walls are only present for structural support.
Cohesion ( attraction of water molecules towards each other) and adhesion (attraction of water molecules and the walls of the tube ) is the reason why  the column doesn't break as these attractive forces overcome the strain developed by Transpiration pull. 
So the correct answer is 'Cohesion and adhesion'.

Multiple choice biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

In root hair, water enters due to.

  1. Diffusion

  2. WP

  3. T.P.

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

Water enters root hairs from the soil primarily due to osmosis, which is driven by the difference in Osmotic Pressure (O.P.) between the root cell sap and the soil water. Root hairs have a higher solute concentration, resulting in a higher osmotic pressure that pulls water inward.

Multiple choice biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

If a cell A with OP $10$ bars and TP $4$ bars is connected to cells B, A and D having OP and TP respectively $4$ and $4$, $10$ and $5$ and $7$ and $3$ bars, the flow of water will be.

  1. C to A, B and D

  2. B to A, C and D

  3. D to A, B and C

  4. A to B, C and D
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Water flows from a region of higher water potential (or lower diffusion pressure deficit / lower osmotic pressure relative to turgor) to a region of lower water potential. Alternatively, using DPD = OP - TP, for cell A: DPD = 10 - 4 = 6. For cell B: OP=4, TP=4, DPD = 0. Since water moves from lower DPD to higher DPD, water flows from cell B (DPD 0) to cell A (DPD 6).

Multiple choice biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

Which of the following elements are most readily mobilised?

  1. Phosphorus, sulphur, nitrogen and potassium

  2. Calcium, sulphur, nitrogen and phosphorus

  3. Phosphorus, sulphur, nitrogen and calcium

  4. Potassium, sulphur, nitrogen and calcium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Phosphorus, sulphur, nitrogen and potassium most readily mobilise while calcium is structural component which is not remobilised.

Multiple choice biology plant kingdom and the environment around us some important plants uses of plants as medicine medicinal plants

Aquatic plants are covered with mucilage which 
a. Make different part of plant spongy 
b. Protects them from pathogens and animals 
c. Functions as lubricant 

  1. a, b

  2. b, c

  3. a, c

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

Aquatic plans are covered with mucilage which protects them from epiphytes, pathogens and animals. It also functions as lubricants. 

Multiple choice biology tissues, organs, organ system, organism defense mechanism in plants epidermal tissue system permanent tissues and their types

Which of the following is not a function of epidermis?

  1. Protection from adverse condition

  2. Gaseous exchange

  3. Conduction of water

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

Epidermis is a single layer of cells found on outer layers in different parts of a plant, viz., leaves, flowers, roots, stem, etc.  Its functions are as follows,

  • It forms a barrier between the underlying tissues in a plant and the surrounding environment, thereby, protecting it from adverse environmental conditions.
  • The presence of stomata and guard cells in the epidermal tissue helps in the exchange of oxygen, carbon dioxide as well as permit transpiration.
  • Conduction of water and minerals in plants takes place in conducting vessels, located in the core, called xylem. Thus conduction of water is not the function of the epidermis but, xylem.