Cambridge IGCSE Biology 0610 · Topic 2.1
Cell Structure
Every organism is built from cells, and the structures present inside a cell are the actual evidence for what kind of cell it is and what it is capable of doing. This section covers what those structures are, in plant, animal and bacterial cells, and how cells build up into the specialised units and levels of organisation that make a whole organism work.
A plant cell and an animal cell share five structures — a cell membrane, cytoplasm, a nucleus, ribosomes and mitochondria — because both need to control what crosses their boundary, carry out chemical reactions, build proteins, release energy and control their own activities. A typical plant cell adds three more: a cellulose cell wall, chloroplasts, and a large permanent vacuole, each one there because of how a plant cell actually lives. A bacterial cell is simpler again, and its defining difference from both is that its genetic material — circular DNA, and often a plasmid or two — is never enclosed inside a nucleus at all.
Once those structures are secure, the same cells reappear in a different role: as specialised units — a root hair cell built for absorption, a red blood cell built for oxygen transport — that combine into tissues, organs and organ systems. Cambridge tests structure, function, and this build-up in organisation as genuinely separate skills, which is why each is covered on its own page below rather than folded into one long list.
What’s in this section
| Page | What it covers |
|---|---|
| Plant and animal cells | The five shared structures, the three plant extras, and the exact evidence that decides which is which on a diagram. |
| Bacterial cells | Why no nucleus is the fact that decides everything else, and what circular DNA and plasmids are doing in the cytoplasm. |
| Specialised cells | The required function of each named cell, and when a question wants the structural adaptation as well. |
| Levels of organisation | Cell, tissue, organ, organ system, organism — the one word that changes at each step. |
All Core
Every page in this section is Core content, required by every candidate regardless of tier. The one Supplement point in the whole chapter — converting between millimetres and micrometres — sits in the separate size of specimens section, not here.