1. Bacteria cannot survive on salted fish because the salt creates a hypertonic environment. In a hypertonic solution, the concentration of solutes outside the bacterial cells is higher than inside. As a result, water moves out of the bacterial cells through osmosis, causing them to shrink and die (a process called plasmolysis).
2.
- A: Tonicity of Solution: Hypertonic; Direction of Water Movement: Out of the cell
- B: Tonicity of Solution: Isotonic; Direction of Water Movement: No net water movement
- C: Tonicity of Solution: Hypotonic; Direction of Water Movement: Into the cell
3.
a. Water moves from the soil into the root hair cell because the concentration of minerals (solutes) is higher inside the root cells than in the soil. This makes the soil hypotonic and the root cells hypertonic relative to the soil. Water moves from an area of lower solute concentration (soil) to an area of higher solute concentration (root cells) via osmosis.
b.
1. The soil is hypotonic compared to the root cells.
2. The root cells are hypertonic compared to the soil.
4. Soft drinks with a high solute concentration should be marketed as "thirst quenchers." These drinks are hypertonic compared to the body's cells. When consumed, they create a hypertonic environment in the digestive system, which can cause water to move out of the body's cells into the digestive tract to dilute the high solute concentration. This can lead to dehydration. Therefore, such drinks are not effective for quenching thirst and may actually worsen dehydration.
Parent Tip: Review the logic above to help your child master the concept of cell membrane transport worksheet.
