A Level Biology Practice Exam

What does it mean for a plant cell to be plasmolysed?

1. Cell content has expanded due to excess water

2. Cell content has shrunk due to loss of water

3. Cell has divided into two identical cells

4. Cell has gained nutrients from the soil

The correct answer is: Cell content has shrunk due to loss of water

A plasmolysed plant cell is characterized by the shrinking of its contents due to water loss, which occurs when the cell is placed in a hypertonic solution. In this situation, water moves out of the cell to balance solute concentrations across the cell membrane. As a result, the central vacuole loses water, causing the cytoplasm to pull away from the cell wall and leading to a reduced turgor pressure. This phenomenon highlights the importance of water in maintaining cell structure and function in plants. The other options do not accurately describe plasmolysis: the first option refers to the opposite situation (cell contents expanding), the third option describes cell division rather than a change in cell water content, and the fourth option speaks about nutrient uptake, which is unrelated to the state of being plasmolysed.