Tag: biology

Questions Related to biology

Which of the following solutions has the highest concentration of the solute?

biology movement in and out of the cell diffusion across cells diffusion and osmosis inter cellular movement

  1. Hypertonic

  2. Hypotonic

  3. Isotonic

  4. None of the above

Show answer
Correct Option: A
Explanation:

Hypotonic solution is a solution, which contains lesser solute concentration. An isotonic solution is a solution, which contains the same concentration of solute as in cell. A Hypertonic solution is a solution, which contains higher solute concentration and thus causes plasmolysis when a cell is placed in such solution.

Diffusion occurs in
(a) Solids
(b) Liquids
(c) Gases

biology movement in and out of the cell diffusion across cells diffusion and osmosis inter cellular movement

  1. a,b

  2. b,c

  3. a,c

  4. All

Show answer
Correct Option: B
Explanation:

Diffusion occurs in both liquids and gases and can take place over long distances diffusion in gases are much faster than in liquids the diffusion rate of oxygen in the air is 1,00,0001,00,000 times more than diffusion rate of oxygen in the water. Diffusion may be defined as the process of movement of gases. Liquids or solutes from the region of higher concentration to the regions of lower concentration till the molecules are uniformly distributed throughout the available space. Many substances like gases. liquids or solutes can diffuse simultaneously in different directions and at different rates in the same place without interfering with each other.

So, the correct answer is B.

The uniformly sweet taste of coffee or tea is due to

biology movement in and out of the cell diffusion across cells diffusion and osmosis inter cellular movement

  1. Spreading

  2. Permeability

  3. Distribution

  4. Diffusion

Show answer
Correct Option: D
Explanation:

Diffusion is the net movement of a substance from a region of high concentration to a region of low concentration. A gradient is a change in the value of a quantity (e.g., concentration, pressure, temperature) with the change in another variable (e.g., distance). The uniformly sweet taste of coffee or tea is also an example of diffusion. Here, when added tea or coffee powder to milk/water, movement of substance takes place from high concentration to lower concentration. Thus, the correct answer is option D.

A cell with fully elastic wall is placed in hypertonic solution. What will not happen?

biology movement in and out of the cell diffusion across cells diffusion and osmosis inter cellular movement

  1. Change in cell size and shape.

  2. The whole cell will shrink.

  3. Cytoplasm shrinks from the cell wall and undergoes plasmolysis.

  4. Decrease in cell size.

Show answer
Correct Option: C
Explanation:

A hypertonic solution is a solution which contains more amount for dissolved salts i.e., the concentration of solute is more.

When a cell is placed in hypertonic solution since the solvent concentration is less, the solvent is exerted from the cell and the cell undergoes cytolysis.

The pressure inside the cell is high and the cell may undergo osmolysis.

Cytoplasm will not shrink but cell solvent will come out it is not plasmolysis because the only periphery of the cell is not affected. So it cannot undergo plasmolysis. 

So the correct answer is 'Cytoplasm shrinks from the cell wall and undergoes plasmolysis'.

The external solution having same concentration as that of cell sap is known as

biology movement in and out of the cell diffusion across cells diffusion and osmosis inter cellular movement

  1. Hypertonic solution

  2. Isotonic solution

  3. Hypotonic solution

  4. Ultratonic solution

Show answer
Correct Option: B
Explanation:

When cells are in isotonic solution, movement of water out of the cell is exactly balanced by movement of water into the cell. 

If concentrations of dissolved solutes are less outside the cell than inside, the concentration of water outside is correspondingly greater. When a cell is exposed to such hypotonic conditions, there is net water movement into the cell. Cells without walls will swell and may burst (lyse)
In hypertonic solutions,  concentrations of dissolved solutes are greater outside the cell and so the concentration of water outside is correspondingly lower. As a result, water inside the cell will flow outwards to attain equilibrium, causing the cell to shrink. As cells lose water, they lose the ability to function or divide. 
There is nothing like ultratonic solution.
Thus, the correct answer is option (B).

The external solution having more concentration than the cell sap is known as

biology movement in and out of the cell diffusion across cells diffusion and osmosis inter cellular movement

  1. Hypertonic solution

  2. Isotonic solution

  3. Hypotonic solution

  4. None of the above

Show answer
Correct Option: A
Explanation:

When cells are in isotonic solution, movement of water out of the cell is exactly balanced by movement of water into the cell. 

If concentrations of dissolved solutes are less outside the cell than inside, the concentration of water outside is correspondingly greater. When a cell is exposed to such hypotonic conditions, there is net water movement into the cell. Cells without walls will swell and may burst (lyse)
In hypertonic solutions, concentrations of dissolved solutes are greater outside the cell and so the concentration of water outside is correspondingly lower. As a result, water inside the cell will flow outwards to attain equilibrium, causing the cell to shrink. As cells lose water, they lose the ability to function or divide. 
Thus, the correct answer is option (A).

When a cell is placed in 0.25 M concentrated sugar solution, there is no change in it. The concentration of cell sap would be :

biology movement in and out of the cell diffusion across cells diffusion and osmosis inter cellular movement

  1. 0.025 M

  2. 0.25 M

  3. 25 M

  4. None of the above

Show answer
Correct Option: B
Explanation:
There are three types of solutions that can occur in your body based on solute concentration: isotonic, hypotonic, and hypertonic. 
A hypertonic solution is one where the concentration of solute is greater outside the cell than inside the cell. An isotonic solution is one in which the concentration of solute is the same both inside and outside of the cell and a hypotonic solution is one in which the concentration of solute is greater inside the cell than outside of it.
So, when the cell is placed in 0.25 M concentrated sugar solution and there is no change in it, the external solution is isotonic, i.e it has the same concentration of 0.25M.
Thus, the correct answer is option (B). 

The external solution having less concentration than the cell sap is known as

biology movement in and out of the cell diffusion across cells diffusion and osmosis inter cellular movement

  1. Hypertonic solution

  2. Isotonic solution

  3. Hypotonic solution

  4. Ultratonic solution

Show answer
Correct Option: C
Explanation:

When cells are in isotonic solution, movement of water out of the cell is exactly balanced by movement of water into the cell. 

If concentrations of dissolved solutes are less outside the cell than inside, the concentration of water outside is correspondingly greater. When a cell is exposed to such hypotonic conditions, there is net water movement into the cell. Cells without walls will swell and may burst (lyse)
In hypertonic solutions, concentrations of dissolved solutes are greater outside the cell and so the concentration of water outside is correspondingly lower. As a result, water inside the cell will flow outwards to attain equilibrium, causing the cell to shrink. As cells lose water, they lose the ability to function or divide. 
Thus, the correct answer is option (C).

To initiate cell photosynthesis, salt solution should be 

biology movement in and out of the cell diffusion across cells diffusion and osmosis inter cellular movement

  1. Isotonic

  2. Hypotonic

  3. Hypertonic

  4. None of the above

Show answer
Correct Option: C
Explanation:

(A) An isotonic solution is a solution where there is no net movement of molecules due to equal concentration on both sides of the cell.
(B) Hypotonic solution is a solution where the movement of molecules is from outside to the inside of the cell.
(C) A hypertonic solution is a solution where the movement of molecules is from inside to outside of the cell.
A hypertonic solution is a solution which contains a high concentration of salt.
When the salt solution is the hypertonic solution then water will enter from outer soil inside the cell so that water will be available for photosynthesis.
So, the correct answer is 'Hypertonic'.

Water is absorbed from outside solution only when it is 

biology movement in and out of the cell diffusion across cells diffusion and osmosis inter cellular movement

  1. Isotonic

  2. Hypotonic

  3. Hypertonic

  4. None of these

Show answer
Correct Option: B
Explanation:

Water is absorbed from outside solution only if the external medium is hypotonic because a hypotonic solution has more concentration of solvent molecules than the fluid inside the cell. So, solvent molecules move inside the cell from the region of higher concentration to the lower concentration by the process of endosmosis. The cell swells and increases in size.

So, the correct answer is option B.