OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

What does it mean when a cell is described as flaccid?

1. There is excess water in the cell

2. The cell is dehydrated

3. Water movement is balanced

4. The cell is actively dividing

The correct answer is: Water movement is balanced

A cell described as flaccid refers to a state where it has lost water and is not under turgor pressure, which is the pressure of the cell contents against the cell wall. In this state, the cell is not fully turgid, leading to a soft and limp appearance. In the context of water movement, a flaccid cell indicates that the movement of water into and out of the cell is balanced, meaning that there is no net movement of water into the cell. This is typical for plant cells in an environment where the concentration of solutes is similar to that inside the cell, leading to an isotonic condition. In an isotonic solution, the osmotic pressure is equal inside and outside the cell, which results in a balanced state of water movement. The other options refer to states that do not align with the definition of flaccidity: excess water would lead to turgidity, dehydration would mean the cell is losing water and becoming plasmolyzed, and active division is unrelated to the cell's water content or turgor state.