CIE iGCSE Co-Ordinated Science B3.1 Diffusion Exam Style Questions Paper 1
Question
Which statements about osmosis are correct?
1 Osmosis requires a membrane.
2 Water can move out of cells by osmosis.
3 Water can move into cells by osmosis.
A 1 and 2 only B 1 and 3 only C 1, 2 and 3 D 2 and 3 only
▶️Answer/Explanation
Ans :C
Question
By which process does oxygen pass from the alveoli to the blood capillaries in the lungs?
(A) growth and nutrition
(B) growth and sensitivity
(C) respiration and nutrition
(D) respiration and sensitivity
▶️Answer/Explanation
Ans: A
Question
What is an example of diffusion?
A. movement of blood through the capillaries
B. movement of food from the mouth to the stomach
C. movement of oxygen from alveoli to the blood
D. movement of urine along the urethra
▶️Answer/Explanation
Answer: C. movement of oxygen from alveoli to the blood
Explanation: Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration. The movement of oxygen from the alveoli (high concentration) to the blood (low concentration) is an example of diffusion.
Question
What is the net movement of molecules during diffusion?
A. from a higher concentration to a lower concentration down a concentration gradient
B. from a higher concentration to a lower concentration up a concentration gradient
C. from a lower concentration to a higher concentration down a concentration gradient
D. from a lower concentration to a higher concentration up a concentration gradient
▶️Answer/Explanation
Answer: A. from a higher concentration to a lower concentration down a concentration gradient
Explanation: Diffusion is the net movement of molecules from an area of higher concentration to an area of lower concentration, down a concentration gradient. This process occurs due to the random motion of particles.
Question
The diagram shows molecules of a gas at different concentrations either side of a permeable membrane.
In which direction will the molecules move?
A. Both ways, but more from P to Q
B. Both ways, but more from Q to P
C. From P to Q only
D. From Q to P only
▶️Answer/Explanation
Answer: A. Both ways, but more from P to Q
Explanation: The molecules will move in both directions due to diffusion, but there will be a net movement from the region of higher concentration (P) to the region of lower concentration (Q).
Question
Which row describes diffusion?
| direction of net movement | type of movement | |
|---|---|---|
| A | higher concentration to lower concentration | non-random |
| B | higher concentration to lower concentration | random |
| C | lower concentration to higher concentration | non-random |
| D | lower concentration to higher concentration | random |
▶️Answer/Explanation
Answer: B
Explanation: Diffusion is the net movement of particles from a region of higher concentration to a region of lower concentration due to random motion of particles.
Question
Which row correctly describes the diffusion of molecules from P to Q?
▶️Answer/Explanation
Answer: A
Explanation: Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration, down the concentration gradient. This process does not require energy and occurs naturally.