1bThe Nature and Variety of Living Organisms
Variety of living organisms — Edexcel Linear - OL Revision Notes & Topical Questions
10 min read 17 parts Lesson 2 of 4 2 quizzes
Lesson summary
Variety of living organisms Edexcel O Level Linear Biology revision notes.A pathogen is a microorganism that causes disease.Bacteria contain plasmids and a circular chromosome.OrganismNucleus?Prokaryote or eukaryoteKingdom featuresPathogensFungi – athlete’s footBacteria – Pneumoc…
- Variety of living organisms Edexcel O Level Linear Biology: what to do next
- Protoctists
- Give / State / Name
- Evaluate / Assess
- Keywords the mark scheme looks for in this lesson
- How to get full marks (examiner guidance)
Part 1 of 5Key ideas
Key ideas
A pathogen is a microorganism that causes disease.
Bacteria contain plasmids and a circular chromosome.
Part 2 of 5Process & sequence
- Organism
- Nucleus?
- Prokaryote or eukaryote
- Kingdom features
Pathogens
Fungi – athlete’s foot
Bacteria – Pneumococcus
Protoctist – Plasmodium (malaria)
Virus – HIV, influenza
Part 3 of 5Summary
Summary
Fungal cell walls are made of chitin.
Viruses can only reproduce inside living cells.
Part 4 of 5Keep going
Variety of living organisms Edexcel O Level Linear Biology: what to do next
These Variety of living organisms Edexcel O Level Linear Biology notes covered the key ideas, worked examples and exam technique for this topic. Check your Variety of living organisms Edexcel O Level Linear Biology understanding with the practice questions below, then reread any Variety of living organisms Edexcel O Level Linear Biology point you were unsure about before moving on.
2
Previous lesson: 1a Characteristics of living organisms — Notes
3
Next lesson: 2a Level of organisation — Notes
4
Course: Edexcel Linear - OL — all units
5
Official syllabus: Pearson Edexcel International GCSEs
Part 5 of 5Compare: Compare
| Group | Cells | Cell wall | Nutrition | Storage | Example |
|---|---|---|---|---|---|
| Plants | Multicellular | Cellulose | Photosynthesis | Starch, sucrose | Maize, pea |
| Animals | Multicellular | None | Feed on organisms | Glycogen | Human, housefly |
| Fungi | Mostly multicellular (yeast single) | Chitin | Saprotrophic | Glycogen | Mucor, yeast |
| Bacteria | Single (prokaryote) | Yes (not cellulose) | Some photosynthesise | — | Lactobacillus, Pneumococcus |
| Protoctists | Mostly single | Some | Varies | — | Amoeba, Chlorella |
| Viruses | Not cells | Protein coat | Parasitic | — | Influenza, HIV, TMV |
Key terms
Command terms
Command terms
Give / State / Name
Recall a fact; one idea per mark.
Define
Give the exact meaning using the specification keywords.
Describe
Give an account of what happens / the pattern in data, quoting values; no reasons needed.
Explain
Give reasons with linked statements (cause → effect). Each linked step is usually a separate marking point.
Suggest
Use knowledge in a new context; more than one answer may be accepted.
Compare
Similarities and differences; each point must refer to both items.
Calculate
Show working; include units; check significant figures. Method marks are given even if the final answer is wrong.
Discuss
Explore the issue from different angles and link the points.
Evaluate / Assess
Weigh strengths and weaknesses and reach a supported judgement.
Deduce
Draw a conclusion from the information given.
Justify
Support a statement/choice with evidence.
Exam technique
Keywords the mark scheme looks for in this lesson
Keywords the mark scheme looks for in this lesson
Eukaryote · Prokaryote · Plants · Fungi · Protoctists · Viruses
Learn each definition in the Key words tab exactly; a missing keyword in a definition usually loses the mark.
How to get full marks (examiner guidance)
How to get full marks (examiner guidance)
Use specification keywords exactly (e.g. eukaryotic/prokaryotic, enzyme–substrate complex, active site, complementary).
Link ideas
Link ideas for “explain” each marking point is usually a cause → consequence step; unlinked facts often score nothing.
Use the information in the question
“discuss/evaluate” answers must use the data provided and match the number of marks.
Convert units carefully (mg → g, cm³ → dm³) and show working for calculations.
Avoid vague words
“it”, “stuff”, “things”, “goes up”, “energy is made”. Name the substance and the process.
Do not extrapolate a graph line beyond the data or to zero unless asked.
Six-mark extended responses are marked on content AND a logical, linked line of reasoning.
Marked practiceQuizzes for this lesson
Last updated:
\n