Biology paper.Absorption by roots.
 ICSE Class10.                            MM30
1.The diagram given below represents a plant cell after being placed in a strong sugar solution. Study the diagram and answer the questions that follow :

A. What is the state of the cell Shown in figure.
B. name the structure that acts as a selectively permeable membrane.
C label the parts numbered 1to4 in the diagram .
D.how can the above cell be  brought back to its original condition ? mention the scientific term for the  recovery of the cell.
E. state any two features of the above plant cell which is not present in animal cells.

2. Choose the correct option from them four options given below
A. a plant cell may burst when
a. turgor pressure equalises  wall pressure.
b turgor pressure exceeds wall pressure.
c wall pressure exceeds turgor pressure d.none of the above

B. Marine  fish when placed in tap water bursts  due to
a.endosmosis b.exosmosis
c.diffusion  d.plasmolysis

C. The space between the the cell wall and plasma membrane in a plasmolysed Cell is filled with
a. isotonic solution
b. hypotonic solution
c.hypertonic solution 
d.water

D.which of the following  is a characteristic not related with the  suitability of the roots for absorbing water .
a. Tremendoys surface area
b.contains cell sap at a higher cincentration than the surrounding soil water.
c.root hairs have thin cell  wall.
d.grow downwards into the soil .

E. Absorption of  water by  plant cells by  surface attraction is called 
a.diffusion 
b.osmosis
c. imbibition 
d.none of these 

F.highest water potential in Osmosis is  that  of 
a.pure  water 
b.10% salt solution
c. 50% sugar solution 
d.honey

3. Differentiate between the following pairs  on the basis of what is mentioned within the brackets 
a.diffusion and osmosis( definition)
b. cell wall and cell membrane ( permeability c.transpiration and guttation ( structures involved )

4.give reasons
a. potato cubes when placed in water become firm and increase in size
b. drooping  of leaves of Mimosa pudica  on being touched

5. name the following
a. pressure of cell content on cell wall 
b.a process by which root hairs absorb  water from soil 
c.the process of uptake of mineral ions against the concentration gradient using energy from the cell .
d.membrane which allows the passage of molecules selectively 
e.a solution in which relative concentration of water molecules and solutes  on either side of cell membrane is same.

6 briefly explain the following terms
a. turgidity  
b.plasmolysis 
c.osmosis 
d.osmotic pressure

7. The figure given below is a diagrammatic representation of a  part of the transverse section of the root  in the root hair zone  .study the same and then answer the following questions 








a.name the parts indicated by  guidelines one to  4 

b.which is the process that enables the passage of water from the soil into the root hair.
c. name the pressure  that is responsible for the movement of water in the direction indicated by arrows 
d.due to excess of this pressure  sometimes drops of water are  found along the leaf margins  of some plants especially on in early morning. what is this phenomena  called? 
e.draw well labelled diagram of the root hair cell as it would appear if excess of fertilizer is added to the soil close to it

By:Ashwani Kumar,Biology teacher,Vigyan Tutorials,Guru Hargobind Nagar Road,patel nagar,Phagwara.9646388266.