Tag: botany

Questions Related to botany

Two cells A and B are adjacent to each other. The cell A has osmotic pressure 13 atm and turgor pressure 5 atm, while the cell B has osmotic pressure 6 atm and turgor pressure 2 atm. the result will be 

  1. Movement of water from cell A to B

  2. Movement of water from cell B to A

  3. Equilibrium of water transport between cell A and B

  4. No movement of water at all


Correct Option: A

Most water flow in root occurs via apoplast as

  1. Cortical cells are living cells

  2. Cortical cells are loosely arranged

  3. Cortical cells are thin walled

  4. All the above


Correct Option: B
Explanation:

Most of the water flow in the roots occurs via Apoplast since the cortical cells are loosely packed, and hence offer no resistance to water movement.

So, the answer is, "Cortical cells are loosely arranged".

Apoplastic movement of water occurs exclusively through the 
(i) Intercellular spaces
(ii) Walls of the cells
(iii) Plasmodesmata
(iv) Cytoplasm

  1. i, ii and iv

  2. iii and iv

  3. i and ii

  4. ii and iv

  5. iv


Correct Option: C
Explanation:
Apoplast absorption is a type of absorption where the water moves through the cell wall and intercellular spaces between the two cell. Water is absorbed by the root hair from the soil. It passes the epidermis, cortex, endodermis, casparian strip and pericycle and xylem. After reaching the xylem it is pulled up by the transpirational pull. 
So, the correct answer is option C.

Although a gridled (upto bast) tree may survive for sometime, but it will eventually die because _________________.

  1. Water will not move upward

  2. Water will not move downward

  3. Sugars and other organic solutes will not move downward

  4. Sugars and other organic solutes will not move upward


Correct Option: A

Following are the differences between apoplast pathway and symplast pathway. Which of the given differences is/are correct?

Apoplast pathway Symplast pathway
(i) It consists of non-living parts of plant body, i.e., cell walls and intercellular spaces. It consists of living parts of plant body, i.e., protoplasts connected by plasmodesmata.
(ii) There is little resistance in the movement of water Some resistance occurs in the movement of water through symplast
(iii) It is slightly slower It is faster
(iv) Metabolic state of root directly affects apoplast pathway Metabolic state of root does not affect symplast pathway
  1. (iii) only

  2. (i) and (iii) only

  3. (iii) and (iv) only

  4. (ii) and (iii) only


Correct Option: C
Explanation:

Apoplast pathway is faster while symplast pathway is slightly slower. Metabolic state of root does not affect apoplast pathway while metabolic state of root directly affects symplast pathway.

In which of the following pathways, movement of water occurs from one cell to another cell through plasmodesmata?

  1. Apoplast pathway

  2. Symplast pathway

  3. Vacuolar pathway

  4. Transmembrane pathway


Correct Option: B
Explanation:

In symplast pathway, water passes from cell to cell through their protoplasm. It does not enter cell vacuoles. The cytoplasm of the adjacent cells are connected through plasmodesmata. Symplastic movement is aided by cytoplasmic streaming of individual cells.

Terms apoplast and symplast were first used by

  1. Clark

  2. Munch

  3. Dixon

  4. Lundegardh


Correct Option: B
Explanation:

Apoplast refers to the non living component of plant like intercellular spaces and cell wall. Transportation through apoplast is fast. 

Symplast refers to living component of plant ie cell membrane and protoplasm. Transportation through symplast is slow process. 
E. Munch (1932), a German physiologist introduced the concept of apoplast and symplast, which is valuable in understanding the pathway of water movement through the root.

Choose the correct answers from the alternatives given.
If cell A with OP = 5 and TP = 4 is surrounded by cells with OP = 3 and TP = 1, what will be the direction of water movement?

  1. From other cells to cell A

  2. From cell A to other cells

  3. Water will not move

  4. None of these


Correct Option: B
Explanation:

DPD or diffusion pressure deficit determines the flow of water. Water moves from low DPD to high DPD. 

DPD is given by: DPD = OP - TP.
In cell A, DPD = 5 - 4 = 1.
In other cells, DPD = 3 - 1 = 2.
Since water moves from low DPD to high DPD, here the movement occurs from cell A to the other cells.
Hence, the correct answer is 'From cell A to other cells'.

The transportation of water and minerals from the root to the leaves is known as ________

  1. Capillary action

  2. Accent of sap

  3. Climbing

  4. Transportation


Correct Option: B
Explanation:

The transportation of water and dissolved minerals from the root to the leaves is known as ascent of sap. It is transported through xylem tissues. During transportation, there is large accumulation of mineral ions in the root hair cells by active transport. This results in the higher water concentration in the soil as compared to the cell sap of the root hair. Hence, water diffuses from the soil into the root hair. The root hair cells become turgid. From root hair cells, the water moves into the cortical cells. From the cortical cells, the water reaches the endodermis by osmosis. The endodermis then pushes water into the xylem tubes through passage cells.

Thus, the correct answer is 'Ascent of sap.'

Which is shown by the experiment Ascent of sap?

  1. The food materials are transmitted by phloem

  2. Water is transmitted by phloem

  3. Water is transmitted by xylem

  4. The food material is transmitted by xylem


Correct Option: C
Explanation:

The ascent of sap experiment demonstrates the absorption of water by root cells if plants and their upwards movement. The sap is the water and minerals absorbed by the roots and they are pushed upwards into the xylem and then it goes to other regions of the plant.

The upward movement of water and minerals is known as ascent of sap.
So the correct answer is 'Water is transmitted by the xylem'.