Download C - Anderson High School

Diffusion & Osmosis Practice Modified
PURPOSE
Understand the processes of diffusion and osmosis in cells.
1. Look at these pictures of a cell surrounded by sugar molecules. The small dots are sugar molecules.
Circle the picture that correctly shows where the sugar molecules should appear after diffusion has
taken place.
Before
After diffusion?
After diffusion?
After diffusion?
2. What is diffusion? ___________________________________________________________________________
3. What is osmosis? ___________________________________________________________________________
5. Which way would the water move in the following? Circle one (Remember: “salt” sucks)
a. Cucumber slice in salt water:
b. Salt poured on a snail:
c.
Into the cucumber
Into the snail
Vegetables sprinkled with water:
Out of the cucumber
Out of the snail
Into the vegetable
Out of the vegetable
6. Look at these diagrams of cells. They show osmosis of water molecules taking place. Shade in one arrow in
each diagram that correctly shows the overall direction in which water molecules will move.
= water
A
B
C
D
7. Circle the letter of the sentence that best explains what osmosis is.
A. Osmosis is the movement of water across a membrane from where it is in high amounts to low amounts.
B. Osmosis is the movement of water across a membrane from where it is in low amounts to high amounts.
C. Osmosis is the movement of water across a membrane if diffusion is not present.
8. Water molecules will move into or out of a cell until the number of molecules in the cell is equal to the
number on the outside. How many water molecules will move in the direction of the shaded arrow
in each of the following?
Cell A _____
Cell B _____
Cell C _____
Cell D _____
For the above pictures, count all of the water molecules inside and
outside of cell. Divide by 2. Figure out how many will need to move so
that they are equal inside and outside the cell (i.e. = the same number)