Tag: botany

Questions Related to botany

Which one is against the theory of ascent of sap by Dixon and Joly?

botany plant physiology mineral absorption transport of food, water and minerals mineral transport theories of translocation transport in the phloem of plants

  1. Pores in tracheary elements

  2. Cohesion force of water molecules

  3. Adhesion force of water molecules

  4. Requirement of ATP

Show answer
Correct Option: D
Explanation:

Dixon and Joly gave the theory that ascent of water in the plant through pored tracheary elements of xylem which uses cohesion-tension, transpiration pull and suction pressure developed in the leaf cells.

According to this theory, there is no use of energy or ATP for the ascent of the sap.
So, the correct answer is 'Requirement of ATP'.

Which of the following is appropriate for mass flow hypothesis?

botany plant physiology mineral absorption transport of food, water and minerals mineral transport theories of translocation transport in the phloem of plants

  1. Large amount of ions are also absorbed alongwith absorption of water.

  2. As suction pressure increases, absorption of water increases and along with water, absorption of ions also increases.

  3. Transpiration pull is responsible for absorption of ions.

  4. All the above.

Show answer
Correct Option: D
Explanation:
Mass flow hypothesis is also known as the pressure flow hypothesis. It was proposed by Ernst Munch in 1930. 
During this process, the large number of ions are absorbed along with the absorption of water. Due to an increase in suction pressure and transpiration pull, absorption of water and ions increases. 
So the correct answer is 'All of the above'.

Cohesion transpiration pull theory of ascent of sap was proposed by 

botany plant physiology mineral absorption transport of food, water and minerals mineral transport theories of translocation transport in the phloem of plants

  1. Munch

  2. Stephen Hales

  3. Dixon and Joly

  4. Bose

Show answer
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

botany plant physiology mineral absorption transport of food, water and minerals mineral transport theories of translocation transport in the phloem of plants

  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

Show answer
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

botany plant physiology mineral absorption transport of food, water and minerals mineral transport theories of translocation transport in the phloem of plants

  1. Swanson

  2. Munch

  3. Curtis

  4. De Vries.

Show answer
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

botany plant physiology mineral absorption transport of food, water and minerals mineral transport theories of translocation transport in the phloem of plants

  1. Plasmalemma

  2. Cell wall

  3. Chloroplast membrane

  4. Mitochondrial membrane

Show answer
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

botany plant physiology mineral absorption transport of food, water and minerals mineral transport theories of translocation transport in the phloem of plants

  1. (a) and (c) are correct

  2. (b) and (c) are incorrect

  3. (a) and (c) are incorrect

  4. (a) and (b) are correct

Show answer
Correct Option: A

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

botany plant physiology mineral absorption transport of food, water and minerals mineral transport theories of translocation transport in the phloem of plants

  1. Xylem

  2. Collenchyma

  3. Phloem

  4. Parenchyma

Show answer
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

botany plant physiology mineral absorption transport of food, water and minerals mineral transport theories of translocation transport in the phloem of plants

  1. Cambium

  2. Pith

  3. Xylem

  4. Phloem

Show answer
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

botany plant physiology mineral absorption transport of food, water and minerals mineral transport theories of translocation transport in the phloem of plants

  1. Phloem

  2. Xylem

  3. Collenchyma

  4. Sclerenchyma

Show answer
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.