About Cell membranes and transport in A Level Biology
Cell membranes and transport is one of the 11 main topics in our A Level Biology (Cambridge (CAIE) 9700) question bank, and about 6% of its real questions come from it. Tayyari Karo has 38 real questions on this topic from 2021 to 2026, from Paper 1, Paper 2; 33 are multiple choice and marked instantly, and the rest are structured questions with a model answer. By difficulty: 20 medium, 10 hard, 8 easy.
Work through the questions below, then open the explanation for each one. Redo the ones you missed a few days later.
Try 6 real questions
These are real past-paper questions. Think of your answer first, then open the explanation.
May/June 2026 · Paper 1 · Cell membranes and transport
Yeast cells have cell walls that contain glycoproteins. The statements describe the process that moves glycoproteins to the cell walls of yeast cells: glycoproteins are packaged into vesicles; vesicles move to the cell surface membrane; vesicles fuse with the cell surface membrane; glycoproteins are released into the cell wall. What is the process that transports glycoproteins to the cell walls?
- active transport
- endocytosis
- exocytosis
- facilitated diffusion
Show answer and explanation
Answer: C. exocytosis
Release of vesicle contents by fusion with the cell surface membrane is exocytosis.
October/November 2025 · Paper 1 · Cell membranes and transport
What are the main roles of glycolipids in cell surface membranes?
1 to help cells to attach to each other to form tissues
2 to act as antigens for cell-to-cell recognition
3 to increase fluidity for the cell surface membrane
- 1, 2 and 3
- 1 and 2 only
- 1 and 3 only
- 2 and 3 only
Show answer and explanation
Answer: B. 1 and 2 only
Glycolipids function in cell-to-cell adhesion and recognition (as antigens); they do not increase membrane fluidity.
May/June 2024 · Paper 1 · Cell membranes and transport
Which statement correctly describes facilitated diffusion?
- The process only occurs using channel proteins that change shape and that use energy provided by the cell.
- The process occurs using channel proteins or carrier proteins that may or may not change shape.
- The process occurs using channel proteins or carrier proteins that use energy provided by the cell.
- The process only occurs using carrier proteins that create a gradient to move ions in opposite directions.
Show answer and explanation
Answer: B. The process occurs using channel proteins or carrier proteins that may or may not change shape.
Facilitated diffusion uses channel proteins (which may or may not change shape, e.g. gated channels) or carrier proteins (which do change shape), but it never uses cellular energy.
May/June 2022 · Paper 1 · Cell membranes and transport
Some processes occurring in cells: 1 endocytosis of water into cells; 2 exocytosis of enzymes from cells; 3 facilitated diffusion of glucose into red blood cells; 4 phagocytosis of dead cells by macrophages. Which processes use ATP?
- 1, 2 and 3
- 1, 2 and 4
- 1, 3 and 4
- 2, 3 and 4
Show answer and explanation
Answer: B. 1, 2 and 4
Endocytosis (1), exocytosis (2) and phagocytosis (4) are all forms of bulk transport requiring ATP; facilitated diffusion (3) moves substances down their concentration gradient without ATP.
October/November 2022 · Paper 1 · Cell membranes and transport
Equal sized potato pieces were placed into a test-tube and covered with a sucrose solution. The test-tube was left for 30 minutes; all other variables were standardised. After 30 minutes, the potato piece had not changed in size. What can be concluded from this result?
- The concentration of sucrose is the same in the potato and in the solution and there is no more movement of water into or out of the potato.
- The concentration of sucrose is the same in the potato and in the solution and there is no net movement of water into the potato.
- The water potential is the same in the potato and in the sucrose solution and there is no more movement of water into or out of the potato.
- The water potential is the same in the potato and in the sucrose solution and there is no net movement of water into or out of the potato.
Show answer and explanation
Answer: D. The water potential is the same in the potato and in the sucrose solution and there is no net movement of water into or out of the potato.
No change in size means no net movement of water, which occurs when water potentials are equal inside and outside the potato cells; water may still move in both directions, just at equal rates (net = zero), and sucrose concentration alone does not determine water movement (water potential does).
October/November 2021 · Paper 1 · Cell membranes and transport
Which properties of phospholipids explain why single layers of phospholipids added to water immediately form bilayers?
1 The hydrophobic fatty acid chains repel water molecules so the tails pack together.
2 The non-polar fatty acid chains are attracted to each other by hydrophobic interactions.
3 Hydrogen bonds form between the phosphate groups and water.
- 1, 2 and 3
- 1 and 2 only
- 1 and 3 only
- 2 and 3 only
Show answer and explanation
Answer: A. 1, 2 and 3
All three properties contribute: the hydrophobic tails pack away from water (1) via hydrophobic interactions (2), while the hydrophilic phosphate heads hydrogen-bond with water (3), together driving spontaneous bilayer formation.
