Explain the effects on plant cells of immersing them in solutions of different concentrations by using the terms: turgid, turgor pressure, plasmolysis, flaccid

SouravNovember 14, 2024

Answer

The effects on plant cells of immersing them in solutions of different concentrations can be described using the terms turgid, turgor pressure, plasmolysis, and flaccid. These terms help explain how plant cells respond to hypertonic, isotonic, and hypotonic environments.

1. Hypertonic Solution

Description

• A hypertonic solution has a higher solute concentration compared to the inside of the plant cell.

Effects on Plant Cells

• Plasmolysis: When plant cells are immersed in a hypertonic solution, water moves out of the cells into the surrounding solution due to osmosis. This loss of water causes the cell’s cytoplasm to shrink away from the rigid cell wall, a process known as plasmolysis.
• Flaccid Cells: As a result of plasmolysis, the cells become flaccid (soft and limp) because they lose turgor pressure—the pressure exerted by the fluid inside the vacuole against the cell wall. The overall structure of the plant may weaken, leading to wilting.

2. Isotonic Solution

Description

• An isotonic solution has an equal solute concentration compared to the inside of the plant cell.

Effects on Plant Cells

• No Net Movement: In an isotonic environment, there is no net movement of water into or out of the cells. Water molecules move across the cell membrane at equal rates in both directions.
• Flaccid State: While the cells do not experience significant changes in volume or pressure, they remain flaccid since they are not under turgor pressure. The plant may not appear wilted but lacks the firmness associated with turgid cells.

3. Hypotonic Solution

Description

• A hypotonic solution has a lower solute concentration compared to the inside of the plant cell.

Effects on Plant Cells

• Turgor Pressure: When plant cells are placed in a hypotonic solution, water moves into the cells by osmosis. This influx of water causes the vacuole to expand, increasing turgor pressure.
• Turgid Cells: As turgor pressure builds up, it pushes the cytoplasm against the cell wall, making the cells turgid (firm and swollen). Turgidity is essential for maintaining structural integrity in plants, supporting leaves and stems and allowing them to stand upright.

Summary

In summary, immersing plant cells in solutions of different concentrations leads to distinct effects:

• In hypertonic solutions, cells undergo plasmolysis and become flaccid due to loss of water and turgor pressure.
• In isotonic solutions, there is no net movement of water; cells remain flaccid without significant changes.
• In hypotonic solutions, cells become turgid as water enters, increasing turgor pressure and maintaining structural support for the plant.