Download osmosis - answers ws osmosis 1314 answers

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Thomases’ Osmosis worksheet
1. How does osmosis differ from simple diffusion? Diffusion is the movement of molecules from an area of high
concentration to an area of low concentration. Osmosis is the same process but it involves water moving through
a membrane.
2. Define: concentration gradient The difference in concentration between to solutions.
3. Identify whether each cell is hypertonic, hypotonic or isotonic to the surrounding solution.
A. This cell is ___hypertonic
to the surrounding solution
B. This cell is__isotonic
to the surrounding solution
C. This cell is _hypotonic_____
to the surrounding solution
4. The solution outside a cell is more concentrated than inside the cell. The cell loses water to its environment. The
external solution is said to be _hypertonic____. This corresponds to diagram _C_ above.
5. The solution inside a cell is more concentrated than outside the cell. The cell gains water from its environment.
The external solution is said to be _hypotonic__. This corresponds to diagram __A__ above.
6. A solution outside a cell has the same concentration as the inside of the cell. The cell does not change in size
because the solution is said to be isotonic____. This corresponds to diagram _B_ above.
7. A salt solution is put on a slug. The slug withers. Is the salt solution hypertonic, hypotonic or isotonic to the slug?
Explain how you know. The salt solution is hypertonic to the slug. I know because the slug shriveled, the water
rushed out of the slug.
8. When two solutions are in dynamic equilibrium (isotonic) do the molecules continue to move in or out of the cell?
Explain your answer. Yes, the molecules continue to move because Brownian movement does not stop except at
absolute zero. The two solutions remain balanced or in equilibrium despite the constant movement of the
molecules.
Below are diagrams of red blood cells. The first diagram shows what the cell looked like before it was put into
a solution. Below are diagrams of the cell after it was placed into the solution. Fill in the blanks:
Original cell before treatment
9. After treatment.
What happened? Molecules continue to move but the two areas stay balanced._
Type of solution the cell was put into: _isotonic_________
10. After treatment.
What happened? _Water moved out of the cell_____
Type of solution the cell was put into: ____hypertonic_______
11. After treatment.
What happened? _water moved into the cell______
Type of solution the cell was put into: __hypotonic_____
Fill in the blank for questions 12 - 16
Word bank: hypotonic, isotonic, hypertonic, plasmolysis, lysis, crenation, turgor. Some words may be used more than
once.
12.
13.
An animal cell placed in a __hypotonic___ solution will burst. This is called lysis).
An animal cell placed in a hypertonic__ solution will shrink. This is called crenation. It crenates
14.
A plant cell placed in a __hypotonic__ solution will become stiff. This is called _turgor
15.
A plant cell placed in a _hypertonic___ solution shrinks away from the cell wall.
This is called ___plasmolysis
16. Animal and plant cells will stay the same size when placed into a __isotonic_____ solution.
17. What causes a plant to wilt? When the large central vacuole does not have enough water, the plant wilts. This can
be caused by under watering or by placing the plant in a hypertonic environment.
18. In the diagrams below, an animal cell (round) and a plant cell (rectangle) are placed in different solutions.
Indicate:
1. In what direction the water moves. (Choices: into cell, out of cell, in & out equally) Round cell is animal.
Square cell is plant.
2. What happens to the cell? (Choices: lyses, crenates, unchanged, plasmolyzes, becomes turgid).
water rushes in, cell bursts
lysis
water rushes out, cell shrinks
crenate
no net change
isotonic
no net movement
cell is unchanged b/c it is in an isotonic solution
water rushes out, cell shrinks
plasmolysis
water rushes in, cell becomes stiff
turgor