Question

When blood cells are placed in \(1%\) (w/v) NaCl aqueous solution, what will happen to the cells?

• A. Cell will burst
• B. Cell will shrink
• C. Cell will swell
• D. Cell remains as such

Hint:

Remember:
• Hypertonic solution \(\rightarrow\) Cell shrinks
• Hypotonic solution \(\rightarrow\) Cell swells/bursts
• Isotonic solution \(\rightarrow\) No change

Answer 1

The Correct Option is B

Concept: This question is based on:
• Osmosis
• Hypertonic and hypotonic solutions
• Osmotic pressure Osmosis is the movement of solvent molecules through a semipermeable membrane from lower solute concentration to higher solute concentration. For human blood cells: \[ 0.9% \text{ NaCl solution} \] is approximately isotonic.

Step 1: Identify the nature of the external solution.
Given external solution: \[ 1% \text{ NaCl} \] Normal isotonic concentration: \[ 0.9% \text{ NaCl} \] Since: \[ 1% > 0.9% \] the external solution is hypertonic.

Step 2: Determine direction of osmosis.
In a hypertonic solution:
• Solute concentration outside cell is greater.
• Water moves out of the cell. This outward movement of water is called: \[ \text{Exosmosis} \]

Step 3: Determine the effect on blood cell.
As water leaves the blood cell:
• Cell volume decreases.
• Cell membrane contracts inward. Therefore, the blood cell shrinks. This shrinking is known as: \[ \text{Crenation} \]

Step 4: Write the final answer.
Hence: \[ \boxed{\text{Cell will shrink}} \] Therefore, the correct option is: \[ \boxed{(B)} \]