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Cambridge IGCSE Biology 0610: Cells and Cell Structure Notes
All living things are made of cells. Animal, plant and bacterial cells share some parts, such as a cell membrane, cytoplasm and ribosomes, but each type also has its own features. These notes cover cell structure in the Cambridge IGCSE Biology (0610) syllabus: labelled diagrams, what each part does, specialised cells, levels of organisation and magnification, with an interactive labelling exercise, a magnification calculator, practice questions and exam tips.
Try the labelling exerciseBook a 1-to-1 lessonWritten by Ms. Humaira Asim, a science teacher with 15+ years of teaching experience. Written for the Cambridge IGCSE Biology 0610 syllabus.
Animal cells
An animal cell has a cell membrane, cytoplasm, a nucleus, mitochondria and ribosomes. It has no cell wall, so its shape can vary. Animal cells may have small, temporary vacuoles, but not a large permanent one.
Plant cells
A plant cell has everything an animal cell has, plus three extra structures: a cell wall, a large permanent vacuole filled with cell sap, and chloroplasts (in cells that carry out photosynthesis, such as leaf cells). Root cells do not have chloroplasts, because they do not receive light.
Bacterial cells
Bacteria are single-celled organisms. A bacterial cell has a cell wall, a cell membrane, cytoplasm and ribosomes, but no nucleus. Its DNA is a single circular DNA loop free in the cytoplasm, and it may also have small extra loops of DNA called plasmids. Bacterial cells are much smaller than plant and animal cells.
What each part does
| Structure | Function |
|---|---|
| Cell membrane | Controls what enters and leaves the cell |
| Cytoplasm | Jelly-like substance where many chemical reactions take place |
| Nucleus | Contains the genetic material (DNA) as chromosomes, which controls the activities of the cell |
| Mitochondria | Where most of the reactions of aerobic respiration take place, releasing energy (Extended) |
| Ribosomes | Where proteins are made (protein synthesis) (Extended) |
| Cell wall | Made of cellulose in plants; strengthens the cell and gives it shape |
| Large permanent vacuole | Contains cell sap; helps keep the cell firm |
| Chloroplasts | Contain chlorophyll, which absorbs light for photosynthesis |
| Circular DNA and plasmids | The genetic material of a bacterial cell |
Comparing the three cell types
| Structure | Animal cell | Plant cell | Bacterial cell |
|---|---|---|---|
| Cell membrane | ✓ | ✓ | ✓ |
| Cytoplasm | ✓ | ✓ | ✓ |
| Ribosomes | ✓ | ✓ | ✓ |
| Nucleus | ✓ | ✓ | ✗ (circular DNA instead) |
| Mitochondria | ✓ | ✓ | ✗ |
| Cell wall | ✗ | ✓ (cellulose) | ✓ (not cellulose) |
| Large permanent vacuole | ✗ | ✓ | ✗ |
| Chloroplasts | ✗ | ✓ (in some cells) | ✗ |
| Plasmids | ✗ | ✗ | ✓ (may have) |
Interactive labelling exercise
Test yourself. Pick the right label for each numbered part. Some labels in the list are there to trick you!
Label the plant cell
Choose the correct label for each number, then press Check my answers.
Label the bacterial cell
Choose the correct label for each number, then press Check my answers.
Specialised cells
Many cells are specialised: their structure is adapted to do a particular job.
| Cell | Function | How it is adapted |
|---|---|---|
| Ciliated cell | Moves mucus in the airways | Tiny hair-like cilia beat to move mucus (and trapped dust and microbes) up and out of the airways |
| Root hair cell | Absorbs water and mineral ions | A long extension gives a large surface area for absorption |
| Palisade mesophyll cell | Photosynthesis | Packed with many chloroplasts, near the top surface of the leaf |
| Neurone (nerve cell) | Carries electrical impulses | Long, thin fibres carry impulses over long distances |
| Red blood cell | Transports oxygen | Contains haemoglobin; has no nucleus, leaving more space for haemoglobin; biconcave shape gives a large surface area |
| Sperm cell | Reproduction | Has a tail (flagellum) to swim, and many mitochondria to release energy |
| Egg cell | Reproduction | Large cell with a store of energy (food reserves) in the cytoplasm |
Levels of organisation
Cells are organised into larger structures:
- A tissue is a group of cells with similar structures, working together to do a shared function.
- An organ is a structure made of a group of tissues, working together to do specific functions.
- An organ system is a group of organs with related functions, working together to do body functions.
Magnification
Cells are too small to see without a microscope. Magnification tells you how many times bigger the image is than the real object.
Measure the image with a ruler in millimetres, then convert to the same unit as the actual size before you divide.
Worked examples
Example 1: calculating magnification
A drawing of a cell is 50 mm long. The real cell is 0.5 mm long. Calculate the magnification.
- M = I ÷ A
- = 50 ÷ 0.5
- = ×100
Example 2: finding the actual size
A photograph of a cheek cell is 30 mm wide at a magnification of ×1500. Calculate the actual width of the cell in µm.
- A = I ÷ M = 30 ÷ 1500 = 0.02 mm
- Convert to µm: 0.02 × 1000
- = 20 µm
Example 3: finding the image size
A mitochondrion is 2 µm long. It is viewed at a magnification of ×10 000. How long is the image in mm?
- I = A × M = 2 × 10 000 = 20 000 µm
- Convert to mm: 20 000 ÷ 1000
- = 20 mm
Example 4: identifying a cell
A cell has a cell wall, a large permanent vacuole and chloroplasts. What type of cell is it?
- Only plant cells have all three of these structures
- It is a plant cell (for example, a leaf cell)
Try it yourself: magnification calculator
Fill in any two boxes and leave the third empty. Use the same unit for image size and actual size.
M = I ÷ A
Convert mm and µm
1 mm = 1000 µm
Common mistakes
- Saying all plant cells have chloroplasts. Root cells do not.
- Saying bacteria have a nucleus. They have circular DNA and plasmids in the cytoplasm instead.
- Mixing up the cell wall and cell membrane. The wall supports the cell; the membrane controls what goes in and out.
- Mixing units in magnification. Convert image size and actual size to the same unit first.
- Giving magnification a unit. Write “×400”, not “400 mm”.
Practice questions
Try each question first, then open it to check your answer.
Q1. Name three structures found in plant cells but not in animal cells.
Cell wall, large permanent vacuole and chloroplasts.
Q2. State the function of the cell membrane.
It controls what enters and leaves the cell.
Q3. Where is the DNA found in a bacterial cell?
In a single circular DNA loop in the cytoplasm, and in plasmids. Bacteria have no nucleus.
Q4. Explain how a root hair cell is adapted for absorbing water.
It has a long extension that gives a large surface area, so more water and mineral ions can be absorbed.
Q5. An image of a cell is 24 mm long. The actual cell is 0.06 mm long. Calculate the magnification.
M = 24 ÷ 0.06 = ×400
Q6. A cell measures 12 mm in a photograph taken at ×3000. Calculate its actual size in µm.
A = 12 ÷ 3000 = 0.004 mm = 4 µm
Q7. Put these in order from smallest to largest: organ system, cell, organ, tissue.
Cell → tissue → organ → organ system
Q8. Suggest why red blood cells have no nucleus.
Without a nucleus, there is more space for haemoglobin, so the cell can carry more oxygen.
Exam tips
- When drawing cells, use clear, single lines and a ruler for label lines. Label lines should touch the structure and must not cross.
- Learn the “plant cell extras”: cell wall, large permanent vacuole, chloroplasts.
- For magnification questions, write the formula, show the unit conversion, then give the answer.
- For specialised cells, link the feature to the function: “a large surface area so that more water is absorbed”.
Frequently asked questions
Are these notes suitable for Year 7, Grade 7 or KS3 science?
Yes. Cells is one of the first topics in Year 7 (KS3) science and in Cambridge Lower Secondary Science Stage 7 (Grade 7). Use the sections on animal and plant cells, what each part does, specialised cells and levels of organisation, and try the labelling exercise. Bacterial cells and unit conversions are extra GCSE and IGCSE content.
What is the difference between a cell wall and a cell membrane?
The cell wall is a tough outer layer (made of cellulose in plants) that supports the cell. The cell membrane is a thin layer inside the wall that controls what enters and leaves the cell. Animal cells have a membrane but no wall.
Do animal cells have vacuoles?
Animal cells can have small, temporary vacuoles, but only plant cells have a large permanent vacuole filled with cell sap.
What is the difference between a tissue and an organ?
A tissue is a group of similar cells working together. An organ is made of several different tissues working together, such as the heart or a leaf.
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Book a 1-to-1 lessonTry the Biology calculatorNext topic: Diffusion, osmosis and active transport. This topic is also part of GCSE and IGCSE Combined Science: see all Combined Science notes. More Biology notes: Biology notes topic list. These notes follow the Cambridge IGCSE Biology 0610 syllabus. Always check the current syllabus on the Cambridge International website.