Concept of water relations_MCQ_Advance Level

Concepts of water relations - Advance

Dear Readers,

Plant–water relations concern how plants control the hydration of their cells, including the collection of water from the soil, its transport within the plant and its loss by evaporation from the leaves. The water status of plants is usually expressed as ‘water potential’, which has units of pressure, is always negative, and in simple form is the algebraic sum of the hydrostatic pressure and the osmotic pressure of water.

Q1.  When a plant cell is placed in a solution which is hypotonic to the cell sap, which of the following conditions will not apply

•  The water potential of the cell sap will rise
•  The suction pressure of the cell sap will fail
•  The cell will become turgid
•  The wall pressure of the cell will fail

The wall pressure of the cell will fail

Q2.  You are given three cells, a root hair, a cell of the inner cortical layer and a cell of the mesophyll. Arrange them in the ascending order of DPD

•  Root hair < Cortical cell < Mesophyll
•  Cortical cell < Mesophyll < Root hair
•  Mesophyll < Root hair < Cortical cell
•  Root hair < Mesophyll < Cortical cell

Root hair < Cortical cell < Mesophyll

Q3.  In a fully turgid cells, the values of DPD, OP and TP will show the tendency

•  DPD = 10 atm. OP = 15 atm. TP = 5 atm.
•  DPD = 5 atm. OP = 12 atm. TP = 7 atm.
•  DPD = 2 atm. OP = 7 atm. TP = 5 atm.
•  DPD = 0 atm. OP = 15 atm. TP = 15 atm.

DPD = 0 atm. OP = 15 atm. TP = 15 atm.

Q4.  Purple cabbage leaves do not loose their colour in cold water but do so in boiling water because

•  Plasma membrane get inactivated in boiling water
•  Hot water can enter the cells readily
•  The pigment is not soluble in cold water
•  The cell wall is killed in boiling water

Plasma membrane get inactivated in boiling water

Q5.  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

•  From cell A to other cells
•   From other cells to cell A
•  Water will not move
•  Water will move up

From cell A to other cells

Q6.  A cell is plasmolysed after being kept in a hypertonic solution. What will be present between cell wall and plasmalemma

•  Isotonic solution
•  Hypertonic solution
•  Air
•  Hypotonic solution

Hypertonic solution

Q7.  Which of the following plants will have maximum osmotic pressure

•  Epiphyte
•  Mesophyte
•  Parasite
•  Halophyte

Halophyte

Q8. When a grape is placed in concentrated sugar solution, then it will show

•  Endosmosis
•  Exosmosis
•  Imbibition
•  None of these

Exosmosis

Q9.  An ideal molar solution at 0°C will have an osmotic pressure of

•  10 atmosphere
•  20 atmosphere
•  22.4 atmosphere
•  14.3 atmosphere

10 atmosphere

Q10.  What will be the direction of movement of water when a solution A having water potential of – 9 bars and another solution B of – 4 bars is separated by a semipermiable membrane

•   B to A
•  A to B
•  Both directions
•  None of these

B to A