Emergency Medical Technician (EMT) Intermediate Practice Exam

What happens to a cell if too much water enters during osmosis?

1. It becomes turgid

2. It undergoes lysis

3. It becomes dehydrated

4. It remains unchanged

The correct answer is: It undergoes lysis

When a cell takes in too much water through osmosis, it can lead to lysis, which is the breaking down or rupture of the cell. This occurs because cells have a semi-permeable membrane that allows water to enter but may not be able to manage excessive increases in volume. In hypotonic environments, where the concentration of solutes is lower outside the cell than inside, water tends to move into the cell in an attempt to balance solute concentrations. If this influx of water exceeds the cell's capacity to handle it, the pressure within the cell increases, ultimately causing the membrane to break and the cell to burst. This phenomenon is particularly true for animal cells, which lack rigid cell walls. Conversely, plant cells, with their strong cell walls, will not lyse in the same way; instead, they become turgid as they fill with water, creating internal pressure that maintains the structure of the plant. Understanding these processes underscores the importance of osmotic balance in cellular health and the implications of solute concentration in different environments.