Bacterial Cell Diagram: Labels and Key Differences
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Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.
Key diagram
A bacterial cell diagram must show a cell wall, cell membrane, cytoplasm, circular DNA (not in a nucleus), plasmids and, where required, a flagellum. Bacteria are prokaryotes and do not have a true nucleus or membrane-bound organelles.
Bacterial cells appear in questions on cell structure comparison and genetic engineering. Students must know which structures are present, which are absent compared with animal and plant cells, and what makes bacteria prokaryotic rather than eukaryotic.
Drawing the bacterial cell
Draw an elongated oval (rod shape) or a circle (coccus shape). Add an outer boundary for the cell wall and a slightly inner line for the cell membrane. The interior is cytoplasm, but draw no nucleus. Instead, draw a single tangled loop in the central region for the circular DNA (sometimes called the nucleoid region). Add one or more small circles for plasmids: these are small extra rings of DNA.
If the question mentions movement, add a wavy line extending from one end for the flagellum.
Why bacteria are prokaryotic
Bacteria lack a true nucleus: their DNA is not enclosed in a nuclear membrane. They also lack mitochondria, chloroplasts, endoplasmic reticulum and other membrane-bound organelles found in eukaryotic cells. This is the defining feature of a prokaryote. Ribosomes are present but are smaller than those in eukaryotic cells.
Structures to compare with eukaryotic cells
Both bacterial and plant cells have a cell wall, but the bacterial cell wall is not made of cellulose. Both have a cell membrane and cytoplasm. Bacteria do not have chloroplasts, mitochondria, a large vacuole or a true nucleus. Plasmids are unique to bacteria in the IGCSE context and are important in genetic engineering because they can be used as vectors to transfer genes.
Label checklist
Check these labels are present and correctly positioned before finishing your drawing.
✓Cell wall
✓Cell membrane
✓Cytoplasm
✓Circular DNA
✓Plasmids
✓Flagellum
✓Ribosomes (smaller than eukaryotic)
Try a diagram question (2 marks)
Name two structures found in a bacterial cell that are not found in an animal cell. [2]
Show the answer and marking guidance
Cell wall
Plasmids (small rings of extra DNA)
Original Cambridge-style practice written for this site.
Common diagram mistakes
Check these against your own drawing before moving on.
Drawing a nucleus inside the bacterial cell: bacteria have no true nucleus.
Labelling the DNA as "chromosome" without saying "circular".
Forgetting plasmids, which are a key feature tested in genetic engineering questions.
Drawing mitochondria or chloroplasts inside a bacterial cell.
Confusing the cell wall material: bacterial cell walls are not made of cellulose.