SPI Biology · Free notes
Microbiology and Disease: SPI Biology
Microbiology and Disease has 7 questions in the SPI bank, six of them EASY, and one is from the 2022 paper: the scientist who made oil-eating bacteria. Every question pairs a name with one fact: a microbe and its use, a disease and its cause, a disease and its organ, a scientist and his work. The wrong options are always real names from the same family, such as another protozoan, another organ or another famous scientist, so learn the pairs exactly.
The handout has every subtopic, worked example, formula and trap with answers shown. The formula sheet is the chapter’s formulas and traps alone, on one page.
Subtopic notes
Microorganisms and Their Uses
5 questionsMicroorganisms are living things too small to see without a microscope: bacteria, fungi, protozoa, algae and viruses, found almost everywhere.
Diseases and Their Causes
2 questionsAn infectious disease is caused by a microbe (a virus, bacterium, protozoan or fungus) and often attacks one particular organ of the body.
Formula & revision sheet
0 formulas · 4 reference tables · 7 gotchas across all subtopics — the exam-eve cheat-sheet
Formula & revision sheet
0 formulas · 4 reference tables · 7 gotchas across all subtopics — the exam-eve cheat-sheet
Reference tables (2)
The groups of microbes and how they feed4 rows
| How it feeds | What it does | Example |
|---|---|---|
| Saprophytic | Digests dead food outside its body, then absorbs it | Rhizopus (bread mould), yeast Outside the body, then absorbed: that is the mark of a saprophyte. |
| Parasitic (plant) | Draws food from a living host plant | Cuscuta |
| Parasitic (animal) | Absorbs food already digested by its host | Tapeworm |
| Symbiotic | Lives with a partner, both gain | Rhizobium in pea roots |
Useful microbes and the scientists behind them5 rows
| Scientist | Known for |
|---|---|
| Louis Pasteur | Pasteurisation |
| Alexander Fleming | Penicillin |
| Edward Jenner | Smallpox vaccine |
| Ananda Mohan Chakrabarty | Oil-eating bacteria for oil spills M S Swaminathan and Norman Borlaug are Green Revolution names, not microbiologists. |
| Robert Hooke | First saw cells |
Watch out for (4)
- A parasite as a saprophyte→ The groups of microbes and how they feed
- Picking one habitat when the options allow all→ The groups of microbes and how they feed
- Green Revolution names for a microbe question→ Useful microbes and the scientists behind them
- Lactobacillus for soil fertility→ Useful microbes and the scientists behind them
Reference tables (2)
Diseases and the microbes that cause them7 rows
| Disease | Caused by | Group | Spread by |
|---|---|---|---|
| Malaria | Plasmodium | Protozoan | Female Anopheles mosquito Plasmodium causes malaria; the mosquito only carries it. |
| Dengue | Dengue virus | Virus | Aedes mosquito |
| Amoebic dysentery | Entamoeba | Protozoan | Dirty water and food |
| Sleeping sickness | Trypanosoma | Protozoan | Tsetse fly |
| Tuberculosis | Mycobacterium | Bacterium | Air |
| Cholera | Vibrio cholerae | Bacterium | Dirty water |
| Ringworm | A fungus | Fungus | Touch |
Diseases and the organ they attack7 rows
| Disease | Organ attacked |
|---|---|
| Hepatitis | Liver Hepar means liver. |
| Jaundice | Liver |
| Tuberculosis | Lungs |
| Pneumonia | Lungs |
| Typhoid | Intestine |
| Conjunctivitis | Eyes |
| Goitre | Thyroid gland |
Watch out for (3)
- Naming the carrier as the cause→ Diseases and the microbes that cause them
- Ringworm is not a worm→ Diseases and the microbes that cause them
- Jaundice of the kidney→ Diseases and the organ they attack
Question weightage by concept
4 concepts · 7 questions — where the marks actually sit, so you know what to drill first
Question weightage by concept
4 concepts · 7 questions — where the marks actually sit, so you know what to drill first
| Concept | Qs | Share |
|---|---|---|
| Useful microbes and the scientists behind them | 3 | 43% |
| The groups of microbes and how they feed | 2 | 29% |
| Concept | Qs | Share |
|---|---|---|
| Diseases and the microbes that cause them | 1 | 14% |
| Diseases and the organ they attack | 1 | 14% |
Test yourself on a real paper
Sit a past SPI paper, timed and marked the way the exam marks it. You see your score and every answer the moment you finish. Free to start.