Question

A cell is placed in a solution that is hypotonic to the cell. Which of the following best describes movement of water in this situation? a. Water will only flow into the cell. b. Water will only flow out of the cell. c. Water will flow into and out of the cell, but the overall net movement will be out of the cell. d. Water will flow into and out of the cell, but the overall net movement will be into the cell.

Short answer

The correct answer is a. Water will only flow into the cell, as the cell is placed in a hypotonic solution, causing water to move from the lower solute concentration of the solution into the cell to balance solute concentrations due to osmosis.

Step-by-step solution

Understand the Hypotonic Solution

A hypotonic solution is a solution that has a lower solute concentration than the cell it surrounds. When a cell is placed in a hypotonic solution, the flow of water occurs according to the principles of osmosis.

Osmosis

Osmosis is the movement of water molecules across a semi-permeable membrane, such as the cell membrane, from an area of lower solute concentration to an area of higher solute concentration. In simple terms, in case of a cell dropped in a hypotonic solution, water molecules move from the hypotonic solution (lower concentration) to the inside of the cell (higher concentration) in order to balance the solute concentration levels on both sides of the cell membrane.

Compare Answer Choices

Now let's compare the given choices with our understanding of hypotonic solution and osmosis: a. Water will only flow into the cell - This statement indicates water movement due to osmosis in a hypotonic solution. b. Water will only flow out of the cell - This statement would be true for a hypertonic solution, not hypotonic. c. Water will flow into and out of the cell, but the overall net movement will be out of the cell - This statement is also applicable to a hypertonic solution, not hypotonic. d. Water will flow into and out of the cell, but the overall net movement will be into the cell - Although water can flow both ways, the net movement indeed is into the cell in the case of a hypotonic solution. However, it gives an incomplete explanation compared to option 'a'.

Choose the Correct Answer

Based on our analysis, the correct answer is: a. Water will only flow into the cell.

Key concepts

Hypotonic Solution

A hypotonic solution is characterized by a lower concentration of solutes outside the cell compared to the inside. This difference creates an environment where the solvent, primarily water, tends to move to where solutes are more concentrated. When a cell is placed in a hypotonic solution, it is surrounded by a solution that causes water to move toward the cell.

This happens because water naturally flows from areas of lower solute concentration to areas with higher solute concentration in an attempt to reach equilibrium. - Understanding this concept is crucial because: - Cells in hypotonic solutions may swell as water moves in. - Prolonged exposure can lead to cell bursting due to excessive water intake. - The movement of water into the cell continues until internal and external solute concentrations equalize.

Cell Membrane

The cell membrane plays a critical role in the process of osmosis, especially when discussing solutions of varying tonicity. It is a semi-permeable membrane which means it allows certain molecules or ions to pass through it while blocking others.

This selective permeability is vital for maintaining homeostasis within the cell. When placed in a hypotonic solution, the semi-permeable membrane facilitates the movement of water into the cell, as water attempts to equalize the solute concentration on both sides. - Important aspects about cell membranes include: - They contain proteins that help in the transport of molecules. - They maintain the cell's shape and protect cellular contents. - They have channels and pores specifically for water and other small molecules. - The structural composition allows cells to regulate their internal environment, ensuring essential cellular functions continue despite external changes.

Solute Concentration

Solute concentration refers to the amount of solute present in a solution. It is a central factor in determining the direction of water movement across the cell membrane during osmosis.

This concentration gradient prompts water movement, which is evident when a cell is in a hypotonic solution. Here, the solute concentration outside the cell is lower compared to the inside, driving water inside as the cell attempts to balance these differences. - Key points to understand: - Higher internal solute concentration draws water inward. - Changes in solute concentration affect cellular processes significantly. - Cells maintain optimal conditions through this balance to function effectively. - Awareness of these solute dynamics helps explain cellular behaviors and their responses to different environments.