1. The document is a biology worksheet about diffusion and osmosis containing multiple choice and short answer questions. 2. Some of the questions ask about the processes of diffusion and osmosis, such as how oxygen moves into root hair cells and examples of osmosis. 3. Other questions provide diagrams and experiments involving plant and animal cells in different solutions to be analyzed in terms of diffusion and osmosis.

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.
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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?
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b) Suggest a reason why microbes find it difficult to survive in jam.
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14. Moths emit chemicals called pheromones to attract a mate.
a) Which process is responsible for the distribution of these chemicals
through the air?
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c) What would be the advantage of a moth releasing the pheromones on a
night when there was little wind?
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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?
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b) Suggest a reason why microbes find it difficult to survive in jam.
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14. Moths emit chemicals called pheromones to attract a mate.
a) Which process is responsible for the distribution of these chemicals
through the air?
____________________________________________________________
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___________________________________________________________
c) What would be the advantage of a moth releasing the pheromones on a
night when there was little wind?
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