What happens when a formalin preserved filament of Spirogyra is placed a hypertonic sugar solution?

Options

A. It loose turgidity
B. It gains turgidity
C. It is plasmolysed
D. Nothing happens

Answer

### Step-by-Step Solution:

1. **Understanding Spirogyra**: Spirogyra is a filamentous green alga known for its spiral chloroplasts. It is a living organism that typically exhibits selective permeability, allowing certain substances to pass in and out of its cells.

2. **Effect of Formalin Preservation**: When Spirogyra is preserved in formalin, it undergoes a process that effectively kills the cells and alters their structure. Formalin is a fixative that denatures proteins and disrupts cellular functions.

3. **Placing in Hypertonic Sugar Solution**: A hypertonic solution has a higher concentration of solutes (in this case, sugar) compared to the inside of the Spirogyra cells. Normally, if the cells were alive, water would move out of the cells by osmosis to balance the concentration of solutes.

4. **Loss of Selective Permeability**: Since the Spirogyra is preserved in formalin, it loses its selective permeability. This means that the cell membranes are no longer functional, and there is no active transport or osmosis occurring.

5. **Resulting Condition**: Because the preserved Spirogyra filament cannot exchange materials with the surrounding hypertonic sugar solution, there is no movement of water or solutes in or out of the cells. As a result, the filament remains unchanged in this environment.

6. **Conclusion**: Therefore, when a formalin-preserved filament of Spirogyra is placed in a hypertonic sugar solution, nothing happens to the filament due to the loss of its cellular functions and selective permeability.