Cell BiologyExam Focus

How This Topic Appears in Exams

Part of Cell Organelles · GCSE GCSE Biology revision

This exam focus covers How This Topic Appears in Exams within Cell Organelles for GCSE Biology. Revise Cell Organelles in Cell Biology for GCSE Biology with 12 exam-style questions and 15 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 11 of 13 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.

Topic position

Section 11 of 13

Practice

12 questions

Recall

15 flashcards

📝 How This Topic Appears in Exams

Typical Question Types

"Name the organelle that..." (1 mark) — e.g., "Name the organelle that is the site of aerobic respiration." Answer: mitochondria (must be spelt correctly or close enough).
"Describe the function of..." (1-2 marks) — e.g., "Describe the function of the nucleus." Expect to give 2 mark points: (1) contains DNA/chromosomes, (2) controls cell activities.
"Explain why [cell type] has many [organelles]" (2-3 marks) — link the organelle function to the cell's job. E.g., "Muscle cells have many mitochondria because they require large amounts of ATP for contraction during aerobic respiration."
"Compare plant and animal cells" (2-4 marks) — always give BOTH similarities AND differences. Use "whereas" or "however" to signal contrast.
Diagram labelling (1 mark per label) — practise identifying organelles from electron micrograph images, not just diagrams.

Key Marks Traps

Saying "the cell wall controls what enters the cell" — this is the cell MEMBRANE's job. The cell wall provides structural support only.
Confusing mitochondria (respiration) with chloroplasts (photosynthesis) — know which does which.
Forgetting that plant cells ALSO have mitochondria — they respire AND photosynthesise.
Saying ribosomes "make energy" — ribosomes make PROTEINS. Mitochondria release energy.

Practice Questions for Cell Organelles

Scientists studying mitochondria use electron microscopes rather than light microscopes. Which statement correctly explains why electron microscopes are more useful for studying cell ultrastructure?

A. Electron microscopes produce a coloured image that makes organelles easier to identify
B. Electron microscopes have a higher resolution, so finer details of organelles can be seen
C. Electron microscopes allow scientists to study living cells in real time
D. Electron microscopes are cheaper and easier to use than light microscopes

1 markfoundation

A researcher is isolating mitochondria from liver cells using cell fractionation. The protocol states the homogenisation solution must be: (i) cold, (ii) isotonic, and (iii) buffered. Explain why each of these three conditions is necessary.

3 marksstandard

Quick Recall Flashcards

What is cell fractionation and what is it used for?

Cell fractionation is a technique that separates organelles from a cell homogenate using differential centrifugation. It allows individual organelle types to be isolated in a pure form so their structure and function can be studied in detail.

What does the term 'ultrastructure' mean in cell biology?

Ultrastructure refers to the fine internal structural detail of cells and organelles — features too small to be seen with a light microscope. Ultrastructure is revealed by electron microscopy. Examples: cristae of mitochondria, thylakoids of chloroplasts, nuclear pores, rough ER ribosomes.