Cell biology: GCSE Combined Science
Eukaryotic and prokaryotic cells, animal and plant organelles, specialised cells, microscopy, mitosis and stem cells
The short version
Compare prokaryotic and eukaryotic cells, name organelles, calculate magnification, and explain mitosis and stem cells.
Key idea
Then add size and extras
Grade 2–3: Bacteria are smaller and do not have a nucleus. Animal cells do.
Grade 5–6: I write eukaryotic = nucleus; prokaryotic = loop of DNA in the cytoplasm. Yeast is eukaryotic because it is a fungus.
Grade 9: I compare in a table: both have cytoplasm, cell membrane and ribosomes. Only eukaryotes have mitochondria and a nucleus. Only bacteria typically have plasmids. I never say bacteria have no DNA.
Go a bit deeper
Question: Give two structures a bacterial cell may have that an animal cell does not. [2 marks]
Step 2. Plasmid and/or flagellum (and the DNA is a loop, not in a nucleus).
Worked example
Worked example
Grade 2–3: Bacteria are smaller and do not have a nucleus. Animal cells do. Grade 5–6: I write eukaryotic = nucleus; prokaryotic = loop of DNA in the cytoplasm. Yeast is eukaryotic because it is a fungus. Grade 9: I compare in a table: both have cytoplasm, cell membrane and ribosomes. Only eukaryotes have mitochondria and a nucleus. Only bacteria typically have plasmids. I never say bacteria have no DNA.
Lessons in this topic
- Eukaryotic and prokaryotic cells
- Animal and plant cells
- Specialised cells
- Microscopy and magnification
- Mitosis and the cell cycle
- Stem cells
In the app each lesson is video (when we have a real YouTube id) then intro, learn and summary steps.
What the examiner wants
Label cells, convert units, use magnification = image / real size, describe the cell cycle, and evaluate embryonic vs adult stem cells with a balanced conclusion.
Try these questions
Cover the answers and have a go first. Worked solutions are underneath.
Which statement about prokaryotic cells is correct?
A typical animal cell is about 20 µm wide. A bacterium is about 2 µm. How many times longer is the animal cell?
Which structures are found in plant cells but not in animal cells?
What is the function of mitochondria?
Common mistakes
- Every cell has DNA. Bacteria lack a nucleus, not DNA. “Bacteria are eukaryotic because they are living” scores 0.
- The cell wall does not control what enters — that is the cell membrane. The wall is fully permeable.
- Osmosis is not water moving from concentrated to dilute. Water moves from a dilute solution (high water potential) to a more concentrated solution.
- 8 mm is not 8 µm. Mixing units is the standard dump.
Answers and working
Frequently asked questions
Is GCSE Cell biology on Combined Science and Triple?
Cell biology is on Combined Science and on Triple Biology. Progress is shared in the ReviseEasy app.
Which exam board is this Cell biology page for?
The ideas are board-agnostic for AQA, Edexcel, OCR, WJEC and CCEA. Paper lengths and question numbers differ — check your specification.
Is Cell biology Foundation or Higher?
The core ideas appear on both tiers. Higher papers add extra application and some HT-only detail, marked in lessons with a Higher badge.
Learn, try, get feedback, fix the mistake
Open the stepped lesson, then the quiz with hints. Required-practical and calculation questions use the same method you will need in the paper.
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