Biology Practice IGCSE Questions

1. GCSE Biology Practice
Questions
Year 11
Diffusion, Osmosis, and
Active Transport
Name: __________________________________
Total Marks Achieved: ________________
Total Marks Available: ________________
Grade / Level: ________________

2. Questions
Q1.
(a) The table lists some structures that provide a large surface area for the diffusion
of substances.
Complete the table by naming the organ in which each structure is found.
The first one has been done for you.
(3)
(b) What is meant by the term diffusion?
(2)
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(c) The nephron is involved in the removal of substances from the blood.
Describe how substances are removed from the blood into the nephron.
(2)
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(Total for question = 7 marks)

3. Q2.
Lily investigated the effect of concentration of a substance on the rate of diffusion.
In a fume cupboard she set up a glass tube with small squares of damp red litmus paper
spaced at 4 cm intervals along its length.
She added 1 drop of ammonia solution to some cotton wool and used tweezers to place
the cotton wool at one end of the tube. She closed the tube with a bung. She timed
how long it took for each square of litmus paper to change colour.
She then set up an identical tube and repeated the experiment, but this time she used
3 drops of ammonia solution.
Her results are shown in the table.
(a) Describe what is meant by the term diffusion.
(2)
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(b) Plot these results on the grid. Use straight lines to join the points.
(6)

4. (c) Describe the results shown by the graph.
(2)
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(d) Calculate the average rate of diffusion, in centimetres per second of ammonia,
from the 3 drops of ammonia solution between the litmus papers at 4 cm and
24 cm. Show your working.
(
Answer ........................................................... cm/s
(e) Explain the difference in the rate of diffusion between the experiment using 1 drop
of ammonia and the experiment using 3 drops of ammonia.
(1)
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(f ) Suggest how Lily could modify her experiment to investigate the effect of temperature
on the rate of diffusion.
(2)
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(Total for question = 15 marks)

5. Q3.
A student investigated the effect of size on the movement of molecules.
He cut three different sized cubes from a block of clear agar jelly.
Cube A was 2 × 2 × 2 cm. Cube B was 1 × 1 × 1 cm and cube C was 0.5 × 0.5 × 0.5 cm.
The student wore safety glasses and placed the cubes in a beaker of red dye solution for five minutes.
He then poured the solution into another beaker, washed the surface of the cubes and dried them with
blotting paper.
He then cut each cube in half and examined the newly cut surfaces.
Diagram 1 shows what the cubes looked like.
(a) Why did he wear safety glasses?
(1)
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(b) Explain how the red dye molecules entered the jelly.
(2)
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(c) Use a ruler to measure the distance the red dye has entered each cube in diagram 1.
(1)
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6. (d) (i) Calculate the surface area of cube A.
(2)
surface area = ................................................. unit .................................
(ii) Calculate the volume of cube A.
(2)
volume = ................................................. unit .................................
(e) The student was told by his teacher that the cubes have different surface area to volume ratios.
Complete the table by putting one tick ( ) in each row to show whether the statement applies to
cube A, B or C.
(3)
(f) Explain how this experiment can be used to understand the need for transport systems in larger
organisms such as humans.
(3)
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(Total for question = 14 marks)
Q4.
The human kidney removes urea from the blood.
(a) Name two other substances the kidney removes from the blood.
(2)
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7. (b) The diagram shows a simple kidney machine that uses dialysis to remove urea
from the blood.
Dialysis allows small molecules to be removed from the blood. This is done by
passing the dialysis solution over the tube containing the blood. The small molecules
move from a region of high concentration to a region of low concentration.
(i) Give one way in which dialysis is similar to diffusion.
(1)
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(ii) Give one way in which dialysis is similar to osmosis.
(1)
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(iii) Describe how the kidney machine removes urea from the blood.
(2)
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(iv) Another function of the kidney machine is to maintain normal blood glucose
concentration.
Suggest how the concentration of glucose in the dialysis solution helps to
maintain a normal glucose concentration in the blood.
(2)
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8. ..............................................................................................................................................
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(v) Describe two processes that take place in the kidney but not in the kidney
machine.
(4)
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(c) Kidney failure can be treated by transplanting a healthy donor kidney into the
patient.
(i) The procedure involves connecting two blood vessels and a tube to the
transplanted kidney.
Name the two blood vessels and the tube.
(2)
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(ii) Suggest why the transplanted kidney is placed in the lower abdomen instead
of in the kidney's usual location.
(2)
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(Total for question = 16 marks)

9. Q5.
A student used this apparatus to find out if nitrate ions helped plants to grow.
A young plant was grown in a solution that contained all the ions needed for growth.
A different young plant was grown in a solution that also contained all the ions
needed for growth except nitrate.
(a) (i) Suggest why the solutions have air bubbled into them.
(2)
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(ii) Suggest why the apparatus was covered in black paper.
(2)
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10. (b) The diagram shows the young plants after 55 days of growth.
(i) Measure the length of the plants in mm and write your answers below.
(2)
plant grown in the solution containing all the ions ........................................................................... mm
plant grown in the solution without nitrate ions ..................................................................................
mm
(ii) Suggest how the student could make the results of the investigation more
reliable.
(1)
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(iii) Suggest two factors, not seen in the diagram, that the student should keep
the same for both plants while they are growing.
(2)
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(c) Explain the consequences of fertiliser containing nitrates polluting a river.
(6)
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(Total for question = 15 marks)

12. Q6.
John wanted to investigate the effect of the size of potato tissue on the rate of osmosis.
He cut three different sized cubes of potato, one 0.5 × 0.5 × 0.5 cm, one 1 × 1 × 1 cm
and one 2 × 2 × 2 cm.
He weighed the potato cubes and recorded their masses.
He then placed each cube into a beaker of distilled water and left them for 1 hour.
He weighed them again and recorded their new masses.
In each case the mass of the potato cubes increased.
The table shows his results.
His teacher told him to calculate the percentage change in mass of each cube.
(a) (i) Calculate the percentage change in mass for the 1 × 1 × 1 cm cube.
Show your working.
(2)
Answer ...........................................................
(ii) Explain why John converted change in mass to percentage change in mass.
(1)
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(b) Use your knowledge of osmosis to explain why the mass of each cube increased.
(3)
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13. (c) John's teacher suggested that the different sized cubes have a different surface area
and volume.
Use the formulae below to calculate the surface area (SA) of each cube, the volume (Vol)
of each cube and their SA:Vol ratios.
SA = 6 × (cube side in cm)2
Vol = (cube side in cm)3
Write your answers in the table below. One cube has been done for you.
(3)
(d) Explain the effect of the different SA:Vol ratios on the rate of osmosis into the potato.
(2)
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(e) Potato tissue is made from plant cells.
Draw and label a plant cell in the space below.
(3)
(Total for question = 14 marks)
Q7.

14. A student prepared some plant cells taken from an onion. She placed the cells in a few drops of distilled
water. She then used a camera attached to a microscope to photograph the cells.
She then added a few drops of concentrated salt solution to the cells and waited a few minutes.
She then took another photograph of the same cells.
(a) Describe the differences in the appearance of the cells in concentrated salt solution compared with
the cells in distilled water.
(2)
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(b) The student thought that the differences in the cells were caused by osmosis.
What is meant by the term osmosis?
(2)
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15. .............................................................................................................................................
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(c) Explain what happens to the cells in concentrated salt solution to change their appearance.
(3)
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(d) Another student investigated the appearance of red blood cells in distilled water and in
concentrated salt solution.
Use your knowledge of osmosis and the structure of red blood cells to describe and explain what the
red blood cells would look like
(i) in distilled water
(2)
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(ii) in concentrated salt solution.
(2)
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(Total for question = 11 marks)

16. Q8.
(a) The diagram shows a plant cell drawn by a student.
(i) Label the diagram to show the selectively permeable membrane.
(1)
(ii) Name three parts of a typical plant cell that are not found in an animal cell.
(3)
1 .....................................................................................................................................................................
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2 .....................................................................................................................................................................
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3 .....................................................................................................................................................................
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(b) The diagram shows a glass container divided in half by a selectively permeable membrane.
One half contains water and the other half contains sucrose solution.

17. (i) Complete the diagram below to show the change to the level of the water
and the level of the sucrose solution after one hour.
(1)
(ii) Name the process that causes the change in the level of the water and the level of the
sucrose solution.
(1)
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(Total for question = 6 marks)

18. Mark Scheme
Q1.

20. Q2.

23. Q3.

25. Q4.

28. Q5.

30. Q6.

33. Q7.

36. Q8.