Select the diagram that represents the shape of a red blood cell when placed in each of the following solutions: Normal red blood cell, hypotonic, hypertonic
0.9 % (m/v) NaCl
Since a hypertonic solution contains a higher concentration of solute particles compared to the red blood cell, the red blood cell would shrivel and become crenated. Therefore, the diagram that represents the shape of a red blood cell in a hypertonic solution (0.9% NaCl) would be diagram C, where the red blood cell appears shrunken and spiky.
In a hypotonic solution, the solution has a lower concentration of solute particles compared to the red blood cell. This causes water to enter the cell, leading to cell swelling and potential bursting. Therefore, the diagram that represents the shape of a red blood cell in a hypotonic solution would be diagram A, where the red blood cell appears enlarged and round.
In a normal red blood cell, the cell is in an isotonic solution where the concentrations of solute particles inside and outside the cell are equal. This means that the cell remains its normal shape. Therefore, the diagram that represents the shape of a red blood cell in a normal solution would be diagram B, where the red blood cell appears disc-shaped and unchanged.
To summarize, the appropriate diagrams that represent the shape of a red blood cell in each of the solutions are:
- Hypertonic solution: Diagram C (shrunken and spiky shape)
- Hypotonic solution: Diagram A (enlarged and round shape)
- Normal solution: Diagram B (disc-shaped and unchanged)
To determine the shape of a red blood cell when placed in different solutions, we need to understand how the solutions affect the cell's membrane.
1. Normal red blood cell: The shape of a red blood cell in an isotonic solution (such as 0.9% NaCl) remains unchanged. The concentration inside the cell is the same as the outside, resulting in no osmotic pressure acting on the cell membrane. Therefore, the red blood cell retains its typical biconcave shape.
2. Hypotonic solution: A hypotonic solution has a lower solute concentration compared to the inside of the red blood cell. When placed in a hypotonic solution, water molecules move into the cell through osmosis, causing it to swell or even burst. The red blood cell becomes swollen and spherical.
3. Hypertonic solution: A hypertonic solution has a higher solute concentration compared to the inside of the red blood cell. When placed in a hypertonic solution, water molecules move out of the cell through osmosis, causing it to shrink or crenate. The red blood cell becomes shrunken and wrinkled.
Therefore, when placed in different solutions, the red blood cell shape can be represented as follows:
- Normal red blood cell: Biconcave shape
- Hypotonic solution: Swollen and spherical shape
- Hypertonic solution: Shrunken and wrinkled shape
To determine how a red blood cell would appear in different solutions, we need to understand the concept of osmosis and the effects of different tonicity on cell shape.
First, let's briefly explain tonicity. Tonicity refers to the concentration of solutes in a solution compared to the concentration of solutes inside the cell. There are three types of tonicity: isotonic, hypotonic, and hypertonic.
- In an isotonic solution, the solute concentration inside and outside the cell is equal. Hence, the cell would maintain its normal shape.
- In a hypotonic solution, the solute concentration outside the cell is lower than inside the cell. This causes water to move into the cell through osmosis, resulting in the cell swelling and potentially bursting.
- In a hypertonic solution, the solute concentration outside the cell is higher than inside the cell. As a result, water moves out of the cell through osmosis, causing the cell to shrink and potentially shrivel up.
Now, let's apply this knowledge to the given solutions. We have a red blood cell and a solution of 0.9% (m/v) NaCl.
- Normal red blood cell: In an isotonic solution, the red blood cell would maintain its normal shape as there is no net movement of water into or out of the cell.
- Hypotonic solution: In a hypotonic solution, such as distilled water or a solution with a lower salt concentration, water would move into the red blood cell, causing it to swell and potentially burst.
- Hypertonic solution: In a hypertonic solution, such as a concentrated salt solution, water would move out of the red blood cell, leading to the cell shrinking and potentially shriveling up.
To select the diagram that represents the shape of the red blood cell in each solution, you would need to identify the cell that matches the description for each tonicity. Look for a diagram that shows a normal shape for the isotonic solution, swelling for the hypotonic solution, and shrinking for the hypertonic solution.