About Cell structure in A Level Biology
Cell structure is one of the 11 main topics in our A Level Biology (Cambridge (CAIE) 9700) question bank, and about 11% of its real questions come from it. Tayyari Karo has 71 real questions on this topic from 2021 to 2026, from Paper 1, Paper 2; 61 are multiple choice and marked instantly, and the rest are structured questions with a model answer. By difficulty: 51 medium, 13 easy, 7 hard.
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 structure
The removal of a plant cell wall by enzyme digestion leaves an intact membrane-bound structure called a protoplast. Which statement explains why protoplasts are easily damaged?
- Mitochondria stop producing ATP to maintain membrane integrity.
- Net movement of water is no longer limited by turgor.
- Secretory vesicles are unable to fuse with the cell surface membrane.
- The shape of the cell structures is changed by the loss of cell shape.
Show answer and explanation
Answer: B. Net movement of water is no longer limited by turgor.
Without the cell wall nothing resists water uptake by osmosis, so the protoplast can burst.
October/November 2025 · Paper 1 · Cell structure
What is a function of Golgi bodies?
- formation of vesicles for endocytosis
- modification of proteins for secretion
- synthesis of ATP
- synthesis of polypeptides
Show answer and explanation
Answer: B. modification of proteins for secretion
Golgi bodies modify (e.g. glycosylate) and package proteins for secretion.
May/June 2024 · Paper 1 · Cell structure
What is the correct order of locations in the cell for the production of an extracellular enzyme?
- nucleus → ribosome → rough endoplasmic reticulum → Golgi body
- ribosome → nucleus → Golgi body → rough endoplasmic reticulum
- ribosome → rough endoplasmic reticulum → nucleus → Golgi body
- rough endoplasmic reticulum → nucleus → Golgi body → ribosome
Show answer and explanation
Answer: A. nucleus → ribosome → rough endoplasmic reticulum → Golgi body
mRNA is made in the nucleus, translated at ribosomes, the polypeptide enters the rough endoplasmic reticulum, then is modified and packaged by the Golgi body before secretion.
May/June 2023 · Paper 1 · Cell structure
Which organelles found in animal or plant cells are surrounded by double membranes?
- chloroplasts, mitochondria, vacuoles
- chloroplasts, mitochondria, nuclei
- chloroplasts, nuclei, vacuoles
- mitochondria, nuclei, vacuoles
Show answer and explanation
Answer: B. chloroplasts, mitochondria, nuclei
Chloroplasts, mitochondria and nuclei all have double (envelope) membranes; vacuoles are surrounded by a single membrane (tonoplast).
May/June 2022 · Paper 1 · Cell structure
What is present in a typical prokaryotic cell and a typical eukaryotic cell?
- 70S ribosomes
- centrioles
- circular DNA in the cytoplasm
- starch granules
Show answer and explanation
Answer: A. 70S ribosomes
Both prokaryotic ribosomes and eukaryotic organelle ribosomes (mitochondria/chloroplasts) are 70S; free eukaryotic cytoplasmic ribosomes are 80S but 70S ribosomes are present in both cell types overall.
October/November 2022 · Paper 1 · Cell structure
A cuboidal epithelium cell has a length of 2 μm. The cell is an approximate cube shape. What is the most accurate estimate of the surface area : volume ratio of this cuboidal epithelium cell?
- 1 : 2
- 1 : 3
- 2 : 1
- 3 : 1
Show answer and explanation
Answer: D. 3 : 1
For a cube of side 2 μm, surface area = 6 × 2² = 24 μm² and volume = 2³ = 8 μm³; ratio = 24:8 = 3:1.
