OCR · A-Level · Biology
Course version: H420 · Version from Sept 2025
(c) (i) the features used to classify organisms into the five kingdoms:…
Full specification wording
Classification and evolution: (c) (i) the features used to classify organisms into the five kingdoms: Prokaryotae, Protoctista, Fungi, Plantae, Animalia
Classification sorts organisms into the five kingdoms using observable and cellular features.
Checked against the OCR H420 specification (opens in a new tab) on .
- Point 3 of 10
- 4 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
Classification sorts organisms into the five kingdoms using observable and cellular features. Prokaryotae have no nucleus or membrane-bound organelles, circular DNA and a peptidoglycan cell wall. Protoctista are mostly single-celled eukaryotes, some photosynthetic, with varied nutrition and no tissue-level organisation. Fungi are eukaryotic, have chitin cell walls, no chlorophyll, and feed by absorbing nutrients after extracellular digestion; their bodies are often hyphae. Plantae are multicellular eukaryotes with cellulose walls, chlorophyll and photosynthesis. Animalia are multicellular eukaryotes with no cell wall, no chlorophyll, and heterotrophic nutrition by ingestion. A useful method is to test each feature in turn: nucleus present? cell wall material? chlorophyll? nutrition mode? number of cells?
What earns the marks
- Prokaryotae: no nucleus and no membrane-bound organelles; circular DNA; peptidoglycan cell wall.
- Protoctista: eukaryotic, mostly single-celled, nutrition varied (photosynthetic or heterotrophic), no true tissues.
- Fungi: eukaryotic, chitin cell wall, no chlorophyll, heterotrophic by absorption after extracellular digestion, often hyphae.
- Plantae: multicellular eukaryotes, cellulose cell wall, chlorophyll, photosynthesis (autotrophic).
- Animalia: multicellular eukaryotes, no cell wall, no chlorophyll, heterotrophic by ingestion.
- Applying several features together, not one alone, to assign an organism to a kingdom.
Common mistakes and how to put them right
Assuming all Protoctista are photosynthetic.
Put it right: Nutrition is varied, some are heterotrophic.
Giving Fungi a cellulose wall.
Put it right: Fungal walls are chitin.
Treating absence of chlorophyll alone as enough to place an organism in Animalia.
Put it right: Check cell wall and nutrition mode too.
Exam tips
- Learn one distinguishing feature per kingdom and a second confirming feature.
- When given an unfamiliar organism, work through a checklist of features rather than guessing.
- Watch for the cell wall material, since it separates Plantae, Fungi and Prokaryotae.
Try the lesson
The start of the Classification and evolution: (c) (i) the features used to classify organisms into the five kingdoms: Prokaryotae, Protoctista, Fungi, Plantae, Animalia lesson, made from checked teaching notes for this specification point.
Have a go first
Which feature distinguishes organisms in kingdom Prokaryotae from those in the other four kingdoms?
Listen
Classification sorts organisms into the five kingdoms using observable and cellular features. Prokaryotae have no nucleus or membrane-bound organelles, circular DNA and a peptidoglycan cell wall. Protoctista are mostly single-celled eukaryotes, some photosynthetic, with varied nutrition and no tissue-level organisation. Fungi are eukaryotic, have chitin cell walls, no chlorophyll, and feed by absorbing nutrients after extracellular digestion; their bodies are often hyphae. Plantae are multicellular eukaryotes with cellulose walls, chlorophyll and photosynthesis. Animalia are multicellular eukaryotes with no cell wall, no chlorophyll, and heterotrophic nutrition by ingestion. A useful method is to test each feature in turn: nucleus present? cell wall material? chlorophyll? nutrition mode? number of cells? A strong answer earns marks for these points. Prokaryotae: no nucleus and no membrane-bound organelles; circular DNA; peptidoglycan cell wall. Protoctista: eukaryotic, mostly single-celled, nutrition varied (photosynthetic or heterotrophic), no true tissues. Fungi: eukaryotic, chitin cell wall, no chlorophyll, heterotrophic by absorption after extracellular digestion, often hyphae. Plantae: multicellular eukaryotes, cellulose cell wall, chlorophyll, photosynthesis (autotrophic). A common slip: Assuming all Protoctista are photosynthetic. Instead, nutrition is varied, some are heterotrophic. Exam tip: Learn one distinguishing feature per kingdom and a second confirming feature.
Key words
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Five-kingdom classification
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Cell structure and wall composition
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Nutrition modes
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Use of multiple features together
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See every definition
- Five-kingdom classification
- Sorting organisms into Prokaryotae, Protoctista, Fungi, Plantae and Animalia using observable and cellular features.
- Cell structure and wall composition
- Prokaryotae have no nucleus or membrane-bound organelles and a peptidoglycan wall, Fungi a chitin wall, Plantae a cellulose wall, and Animalia no cell wall.
- Nutrition modes
- Nutrition is varied in Protoctista, heterotrophic by absorption after extracellular digestion in Fungi, photosynthesis in Plantae, and heterotrophic by ingestion in Animalia.
- Use of multiple features together
- Testing each feature in turn, such as nucleus present, cell wall material, chlorophyll, nutrition mode and number of cells, rather than one alone.
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