Tag: mineral transport

Questions Related to mineral transport

Cohesion transpiration pull theory of ascent of sap was proposed by 

  1. Munch

  2. Stephen Hales

  3. Dixon and Joly

  4. Bose


Correct Option: C
Explanation:

Cohesion transpiration pull theory was proposed by Dixon and Jolly. They proved that cohesion and adhesion support continuity of water columns and provide strength like a steel wire, transpiration pulls water columns towards leaves which causes ascent of sap.

So, the correct answer is 'Dixon and Jolly'.

Match the lists and find the correct option 


   LIST I    LIST II
 A.  Henry Dixon  1.   Bioelectric response
 B.  Slatyer and Taylor  2.  Cohesion tension theory
 C.  Levitt  3.  Active proton concept
 D.  J. C. Bose  4.  Water potential
     5.  Term physiology

  1. A - 3, B - 4, C - 2, D - 1

  2. A - 1, B - 2, C - 4, D - 3

  3. A - 4, B - 1, C - 2, D - 3

  4. A - 2, B - 4, C - 3, D - 1


Correct Option: D
Explanation:

Cohesion tension theory was proposed by John Joly and Henry Horatio Dixon in the year 1894. The theory has two fundamental features such as (i) cohesion of water and adhesion between water and xylem tiusses, (ii) Transpiration pull. This theory explains plants which is responsible for the movement of water column upward.

Water potential term was coined by Slatyer and Taylor in the year 1960. He proposed that chemical potential of water be used as a property of water in plant soil air system.
Levitt in 1974 gave a altered form of the mechanism of stomatal movement which was called the proton - potassium pump hypothesis. This hypothesis explains K+ ions are transported into the guard cells in the presence of light. This is termed as active proton concept.
J. C. Bose invented rare, elegant apparatus for together measuring bioelectric potentials and for computing very small movements in plants. Bose concluded that plants and animals have substantially the same essential physiological mechanisms. Based on electrical signalling all plants co-ordinate their movements and responses to the environment. 
So, the correct answer is option D.

Mass flow hypothesis was put forward by

  1. Swanson

  2. Munch

  3. Curtis

  4. De Vries.


Correct Option: B
Explanation:

Mass flow hypothesis is also known as pressure flow hypothesis it is the best-supported theory to explain the movement of sap through the phloem. It was discovered by the scientist by Ernst Munch in 1930, He was the German plant physiologist. This creates the hydrostatic pressure in the phloem of the plant.

So, the correct option is B.

Choose the correct answers from the alternatives given.
An example of selectively permeable membrane is

  1. Plasmalemma

  2. Cell wall

  3. Chloroplast membrane

  4. Mitochondrial membrane


Correct Option: A
Explanation:

Cell membrane, also known as plasmalemma, is the innermost membrane of a plant cell. It is surrounded by a cell wall. The cell membrane is a selectively permeable membrane that allows only some type of compounds to pass through. The membrane has a phospholipid structure that contributes to this property.

Hence, the correct answer is 'Plasmalemma'.

According to mass flow hypothesis
(a) Sucrose is moved into the companion cells and then into the sieve tube by passive transport.
(b) Inside the phloem, an osmotic pressure gradient is generated that facilitates the mass movement in the phloem.
(c) Water in the adjacent xylem moves into the phloem by active process

  1. (a) and (c) are correct

  2. (b) and (c) are incorrect

  3. (a) and (c) are incorrect

  4. (a) and (b) are correct


Correct Option: A

Which of the following is related with transfer of food material?

  1. Xylem

  2. Collenchyma

  3. Phloem

  4. Parenchyma


Correct Option: C
Explanation:

Xylem tissue is comprised of dead cells involved in the process of transport of water and minerals. Transport of water is under the influence of transpiration pull and is a physical process. 

Phloem tissue is comprised of living cells involved in the process of translocation of sugars. Translocation of sugars requires living cells and is a physiological process. The sugars are transported under the influence of pressure difference between source and sink, which leads to mass flow.

Leaf photosynthates are transported to other parts of higher plants through

  1. Cambium

  2. Pith

  3. Xylem

  4. Phloem


Correct Option: D
Explanation:

Phloem is involved in transport of sugars. Phloem cells are living cells, which carry out the physiological process of sugar transport in higher plants.

By many evidences, it can be known that the downward movement of food takes place through

  1. Phloem

  2. Xylem

  3. Collenchyma

  4. Sclerenchyma


Correct Option: A
Explanation:

Movement of food takes place through phloem tissue. This can be demonstrated through ringing experiment in which, if ring of vascular tissue including phloem is removed in a dicot tree. The plant parts located below the point of ringing will die because these parts do not get food.

Thus, the correct answer is option A.

How many of the following features are related to Dixon and Jolly model of water transport in plants?
a. Cohesion between water molecules
b. Transpiration pull
c. Pushing of water by negative root pressure
d. Surface tension
e. Pushing of water by positive root pressure.

  1. $4$

  2. $5$

  3. $2$

  4. $3$


Correct Option: A

Bulk flow or mass flow.

  1. Can be achieved through root pressure

  2. Can be achieved through transpiration pull

  3. Can be achieved either through a positive Hydrostatic pressure or a negative hydrostatic pressure

  4. More than one option is correct


Correct Option: A