worksheet

1. Saint Francis Methodist School, Singapore
TOPIC:- DIFFUSION AND OSMOSIS SUBJECT:- BIOLOGY
WORKSHEET NUMBER:- 1 CLASS:- 3C
NAME- DATE:-
Prepared by- Neeti Pal
Q. Choose the correct answer and write in the bracket given:
1. Which shows the changes in appearance of a plant cell as it remains in a
concentrated sugar solution for thirty minutes?
[ ]
2. By which process does oxygen move into the cytoplasm of a root hair cell?
A diffusion
B osmosis
C photosynthesis
D transpiration [ ]
3. What is an example of osmosis?
A Carbon dioxide goes out through the stomata of a leaf.
B Digested food is absorbed from the small intestine.
C Oxygen goes into the blood from an alveolus.
D Water enters a plant root from the soil. [ ]
4. Which diagram shows the appearance of a plant cell several minutes after

2. it has been placed in a concentrated solution of sugar?
[ ]
5. The dots represent molecules of a gas in four tubes at the beginning of an
experiment. In which tube will more molecules move from X to Y than in the
opposite direction?
6. The diagrams show an experiment when set up and the same experiment
two hours later.

3. 7. A student investigated osmosis in potatoes. He set up the apparatus
shown.
At the beginning the potato cylinders were exactly balanced. He immersed the
cylinders into the liquids for 4 hours, after which the cylinders were lifted out of
the liquids. Cylinder P was now heavier than cylinder Q. Which statement
explains what happened?
A Water moved into both cylinders.
B Water moved out of both cylinders.
C Water moved into the cylinder in the distilled water and out of the cylinder
in the sugar solution.
D Water moved out of the cylinder in the distilled water and into the cylinder
in the sugar solution.
8. Where and how does carbon dioxide enter a plant?

4. 9. Diagram 1 shows an onion cell that has been placed in pure water.
Which statement explains the
change?
A Sugar has moved into the cell.
B Sugar has moved out of the cell.
C Water has moved into the cell.
D Water has moved out of the cell.
II. Answer the following questions in the given spaces:
10. Rita says, “Osmosis is special case of diffusion”. Is Rita right? Explain.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
11. Complete the following table:
Diffusion Osmosis
Similarity 1
Similarity 2
Difference 1
Difference 2
12. Complete the sentence:
A. Diffusion is the _______ movement of particles from a ___________
concentration to a _________________concentration until they are spread
out ________.
B. Osmosis is the passage of ______ molecules from a ____ concentrated
solution to a ______ concentrated solution through a
______________

5. 13. Jam is a very strong solution of sugar. By contrast the cytoplasm in a
microbe is a much weaker solution.
a) The cell wall of a microbe is made up of a semi-permeable membrane.
Would water flow from the microbe to the jam, or from the jam to the microbe
by osmosis?
______________________________________________________________
______________________________________________________________
b) Suggest a reason why microbes find it difficult to survive in jam.
______________________________________________________________
______________________________________________________________
______________________________________________________________
14. Moths emit chemicals called pheromones to attract a mate.
a) Which process is responsible for the distribution of these chemicals
through the air?
____________________________________________________________
___________________________________________________________
___________________________________________________________
c) What would be the advantage of a moth releasing the pheromones on a
night when there was little wind?
____________________________________________________________
____________________________________________________________
____________________________________________________________
____________________________________________________________

6. 13. Jam is a very strong solution of sugar. By contrast the cytoplasm in a
microbe is a much weaker solution.
a) The cell wall of a microbe is made up of a semi-permeable membrane.
Would water flow from the microbe to the jam, or from the jam to the microbe
by osmosis?
______________________________________________________________
______________________________________________________________
b) Suggest a reason why microbes find it difficult to survive in jam.
______________________________________________________________
______________________________________________________________
______________________________________________________________
14. Moths emit chemicals called pheromones to attract a mate.
a) Which process is responsible for the distribution of these chemicals
through the air?
____________________________________________________________
___________________________________________________________
___________________________________________________________
c) What would be the advantage of a moth releasing the pheromones on a
night when there was little wind?
____________________________________________________________
____________________________________________________________
____________________________________________________________
____________________________________________________________