AP Biology Osmosis

A sample of human blood was placed in a test tube containing a physiological saline solution (0.9% sodium

chloride). This type of solution is often used intravenously to quickly rehydrate patients. A drop of the blood

from the test tube was placed on a slide and red blood cells (RBCs) were observed under a microscope. Three

possible outcomes are diagrammed above. Which of the following best predicts which diagrammed microscope view the laboratory worker would see and best explains why?

• View 1 because RBC membranes are freely permeable to water

• View 2 because the RBCs use energy to allow sodium entry and to pump water out

• View 2 because the rate of water movement into the RBCs equals the rate of water movement out of the cells

• View 3 because the sodium-potassium pumps in the RBC membranes use energy to keep the sodium out but allow water to freely flow into the cells

Tags

NGSS.HS-LS1-3

Which way would the purple molecules move through the semi-permeable membrane?

• From the  A side  to the B-side
• From the B side to the A side
• none of the purple molecules would move
• they would move equally back and forth in a state of dynamic equilibrium

Tags

NGSS.HS-PS1-5

When cells are placed in a __________ solution they begin to swell.

• Hypertonic
• Isotonic
• Hypotonic
• Equalized

Tags

NGSS.MS-LS1-2

A person would never have pure water put into their veins in a hospital because their cells would...

• Shrink/Dehydrate
• Expand

Tags

NGSS.HS-LS1-3

A saltwater snail is placed in freshwater. What happens to its cells?

• They shrink
• They swell
• Nothing happens

Tags

NGSS.HS-LS1-3

 If a cell containing 5% salt is placed into a glass of water with 20% salt, the water is _______ compared to the cell.

• hypertonic-
• hypotonic
• isotonic

If you looked at red blood cells under a microscope and saw the blood cells exploded, what would you say happened?

• The cells were placed in a hypotonic solution.
• the solution was isotonic.
• The solution was hypertonic.

Water will move?

• Into the cell
• Out of the cell
• Neither into or out of the cell

Tags

NGSS.HS-LS1-3

Where will water move in this situation?

• Into the cell

• Out of the cell

• No movement

• Into its parent's basement

How would you classify the solution in this situation?

• Hypotonic

• Isotonic

• Hypertonic

• Catatonic

Tags

NGSS.HS-PS1-5