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 botany the leaf mechanism of absorption mineral absorption significance of transpiration

Generally, gravitational water is utilized by the plants.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Gravitational water is free water moving through soil by the force of gravity. It is largely found in the macropores of soil and very little gravitational water is available to plants as it drains rapidly down the water table in all except the most compact of soils.

So, the correct answer is 'False'.
Multiple choice botany simple nutrients into cells mineral transport types of transport translocation of organic solutes

Which is the control point in roots where a plant adjust the quantity and quality of solute that reach the xylem:

  1. At root hair cell

  2. At endodermal cell

  3. At pericycle

  4. At cortical cell
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The plants need to change the sort and amount of solutes that achieve the xylem. The vehicle proteins of endodermal cell help in keeping up and changing solute development. 
So, the correct option is 'At endodermal cell'.
Multiple choice botany simple nutrients into cells mineral transport types of transport translocation of organic solutes

Much of starch is deposited in fruits as it matures. Which of the following explains that how the starch gets there?

  1. Starch solution passes through cells from xylem to fruit.

  2. Starch solution passes through companion cells to fruit.

  3. Starch grains passes through cells from xylem to fruit.

  4. A sugar solution passes through phloem cells to the fruit, where it is changed to starch.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

According to the most widely accepted theory of translocation of organic solutes - 'Mass flow hypothesis' or 'Pressure flow hypothesis', organic substances move in the sieve tubes from the region of higher osmotic concentration to the region of lower osmotic concentration in a mass flow, due to occurrence of a pressure gradient. 

Sucrose is the most commonly translocated sugar. At the source end sucrose is actively uploaded into the sieve tubes with the help of companion cells. At the storage organ / fruit end sucrose is actively downloaded from the sieve tubes and converted to starch for long term storage. 
As starch is tasteless, unripe fruits are tasteless and hard. Subsequently during fruit ripening starch is converted to sugars for utilisation during respiration. Hence, fruits become soft and sweet on ripening.

Multiple choice botany simple nutrients into cells mineral transport types of transport translocation of organic solutes

Translocation of food in higher plants is related to the idea of

  1. Source and sink

  2. Ascent of sap

  3. Diffusion

  4. Cyclosis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Translocation of organic solutes in phloem is bidirectional. The transport of prepared food is from source to sink. The source is the area, where sugars are present in larger amount either because they are synthesized there, example leaves or are stored there, example storage organs. 

Sink is the region of sugar utilisation. Where ever sugars are present in higher concentration, from there, sugars will be transported to a region, where sugars are required for metabolism or need to be stored. The loading of sugars at source as well as unloading of sugars at the sink both the processes are active and require expenditure of metabolic energy.

Multiple choice botany simple nutrients into cells mineral transport types of transport translocation of organic solutes

Which of the following act as sink?

  1. Root cells

  2. Fruit

  3. Seeds

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

Translocation of organic solutes in phloem is bidirectional. The transport of prepared food is from source to sink. 

The source is the area, where sugars are present in larger amount either because they are synthesized there example leaves sink in the region of sugar utilisation. There is a dynamic balance between source and sink and they also keep on shifting depending on the physiological requirements of the plant. 
In some plants like carrot, radish etc., sugars are stored in roots. 
Hence, in these plants roots serve as sink. 
In most of the plants fruits serve as sink because they store food in epicarp. Seeds store food for the embryo. Seed store food in endosperm or cotyledons. Hence, seeds serve as sink.

Multiple choice biology transportation in plants and circulation in animals mineral transport types of transport translocation of organic solutes

Which pressure is responsible for ascent of sap?

  1. Negative hydrostatic pressure

  2. Positive hydrostatic pressure

  3. Root pressure

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • In the Root Pressure, the root Xylem vessels absorb the minerals from the soil, as a result, the water potential outside the root increase and inside the root decreases so due to water potential difference water starts entering to the xylem of the root.

So, the correct answer is 'Root pressure'
Multiple choice biology transportation in plants and circulation in animals mineral transport types of transport translocation of organic solutes

Root pressure is caused by

  1. Osmosis

  2. Diffusion

  3. Passive transport

  4. Uphill transport
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Root pressure is caused in the Xylem vessels due to osmosis. It is a positive pressure which is developed due to Osmotic pressure which is high in the root as compared to the water column above.

Diffusion is a very slow process and hence plant do not just depend on it for the ascent of sap.
Since it is not occurring through specialised proteins or usage of energy, it is neither passive transport nor uphill transport 
So the correct answer is 'Osmosis'.

Multiple choice biology transportation in plants and circulation in animals mineral transport types of transport translocation of organic solutes

Which condition will not favour guttation?

  1. High moisture

  2. High DPD in leaf

  3. Accumulation of ions in root side

  4. Low light intensity
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Guttation occurs due to high root pressure when transpiration is low. A high DPD (Diffusion Pressure Deficit) in the leaf indicates water stress, which would pull water into the leaf cells rather than forcing it out through hydathodes.

Multiple choice biology transportation in plants and circulation in animals mineral transport types of transport translocation of organic solutes

Identify the correct sequence of movement of water in the root of higher plants.

  1. Epidermic - Cortex -Pericycle-endodermis - phloem

  2. Epidermis -Cortex-endodermis -pericycle -phloem

  3. Epidermis -Cortex -pericycle-endodermis -xylem

  4. Epidermis -Cortex-endodermis-pericycle -xylem
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Water will take the path of least resistance through root to reach the xylem. Water can move across the root via three different pathways. Once in the endodermal cells, the water freely enters the xylem cells where it joins the fast-moving column of water or transpiration stream, headed to the leaves.
So the correct option is 'Epidemic - Cortex -Pericycle-endodermis - phloem'.
Multiple choice biology transportation in plants and circulation in animals mineral transport types of transport translocation of organic solutes

Force responsible for exudation of liquid drops from the margin of the leaves is

  1. Negative hydrostatic

  2. Transpiration pull

  3. Imbibition

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

  • Negative hydrostatic pressure develops at the time of water loss, it occurs when the water is lost through transpiration and creates tension in the cell.
  • Transpiration is the process in which water is lost through the upper or aerial plant parts in the form of water. 
  • Imbibition is the swelling of cells that occurs due to the absorption of water. 
  • Positive pressure is the force in the xylem which exudates drops of liquids through the stoma to the outside and also requires hydathodes which help in the process of guttation (exudation of water droplets mostly from the leaves margins). 
So, the correct option is 'Positive pressure'.

Multiple choice biology animal tissues, morphology and anatomy of cockroach specialized cells in animals tissues and types of tissues levels of organisation in animals

Unlike animals, plants get energy in the form of

  1. ATP

  2. Soil

  3. Roots

  4. Water
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Chloroplasts contain a pigment called chlorophyll. Chlorophyll is able to capture the energy from the sun. In doing this, a series of chemical reactions occur that convert the sun's energy into ATP (energy for the plant). 

Therefore, the correct answer is option A.