Biology AS CIE
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1-cell-structure10 主题
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1-2-cells-as-the-basic-units-of-living-organisms AS viruses
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1-2-cells-as-the-basic-units-of-living-organisms AS prokaryotic-v-eukaryotic-cells
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1-2-cells-as-the-basic-units-of-living-organisms AS the-vital-role-of-atp
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1-2-cells-as-the-basic-units-of-living-organisms AS animal-and-plant-cells
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1-2-cells-as-the-basic-units-of-living-organisms AS eukaryotic-cell-structures-and-functions
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1-1-the-microscope-in-cell-studies AS calculating-actual-size
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1-1-the-microscope-in-cell-studies AS resolution-and-magnification
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1-1-the-microscope-in-cell-studies AS eyepiece-graticules-and-stage-micrometers
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1-1-the-microscope-in-cell-studies AS magnification-calculations
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1-1-the-microscope-in-cell-studies AS the-microscope-in-cell-studies
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1-2-cells-as-the-basic-units-of-living-organisms AS viruses
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2-biological-molecules19 主题
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2-4-water AS water-and-the-hydrogen-bond
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2-4-water AS the-role-of-water-in-living-organisms
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2-3-proteins AS collagen
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2-3-proteins AS haemoglobin
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2-3-proteins AS globular-and-fibrous-proteins
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2-3-proteins AS protein-shape
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2-3-proteins AS the-four-levels-of-protein-structure
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2-3-proteins AS amino-acids-and-the-peptide-bond
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2-2-carbohydrates-and-lipids AS phospholipids
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2-2-carbohydrates-and-lipids AS triglycerides
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2-2-carbohydrates-and-lipids AS cellulose
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2-2-carbohydrates-and-lipids AS starch-and-glycogen
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2-2-carbohydrates-and-lipids AS the-glycosidic-bond
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2-2-carbohydrates-and-lipids AS reducing-and-non-reducing-sugars
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2-2-carbohydrates-and-lipids AS covalent-bonds-in-polymers
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2-2-carbohydrates-and-lipids AS biological-molecules-key-terms
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2-1-testing-for-biological-molecules AS testing-for-non-reducing-sugars
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2-1-testing-for-biological-molecules AS the-benedicts-test
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2-1-testing-for-biological-molecules AS biological-molecule-tests
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2-4-water AS water-and-the-hydrogen-bond
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3-enzymes13 主题
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3-2-factors-that-affect-enzyme-action AS enzyme-activity-immobilised-v-free
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3-2-factors-that-affect-enzyme-action AS enzyme-inhibitors
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3-2-factors-that-affect-enzyme-action AS vmax-and-the-michaelis-menten-constant
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3-2-factors-that-affect-enzyme-action AS rate-inhibitor-concentration
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3-2-factors-that-affect-enzyme-action AS rate-substrate-concentration
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3-2-factors-that-affect-enzyme-action AS rate-enzyme-concentration
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3-2-factors-that-affect-enzyme-action AS rate-ph
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3-2-factors-that-affect-enzyme-action AS rate-temperature
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3-1-mode-of-action-of-enzymes AS colorimetry
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3-1-mode-of-action-of-enzymes AS measuring-enzyme-activity
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3-1-mode-of-action-of-enzymes AS how-enzymes-work
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3-1-mode-of-action-of-enzymes AS enzyme-action
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3-1-mode-of-action-of-enzymes AS enzymes
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3-2-factors-that-affect-enzyme-action AS enzyme-activity-immobilised-v-free
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4-cell-membranes-and-transport16 主题
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4-2-movement-into-and-out-of-cells AS comparing-osmosis-in-plants-and-animals
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4-2-movement-into-and-out-of-cells AS osmosis-in-animals
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4-2-movement-into-and-out-of-cells AS osmosis-in-plant-cells
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4-2-movement-into-and-out-of-cells AS estimating-water-potential-in-plants
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4-2-movement-into-and-out-of-cells AS investigating-surface-area
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4-2-movement-into-and-out-of-cells AS surface-area-to-volume-ratios
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4-2-movement-into-and-out-of-cells AS investigating-diffusion
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4-2-movement-into-and-out-of-cells AS investigating-transport-processes-in-plants
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4-2-movement-into-and-out-of-cells AS endocytosis-and-exocytosis
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4-2-movement-into-and-out-of-cells AS active-transport
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4-2-movement-into-and-out-of-cells AS osmosis
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4-2-movement-into-and-out-of-cells AS diffusion
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4-1-fluid-mosaic-membranes AS cell-signalling
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4-1-fluid-mosaic-membranes AS the-cell-surface-membrane
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4-1-fluid-mosaic-membranes AS components-of-cell-surface-membranes
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4-1-fluid-mosaic-membranes AS the-fluid-mosaic-model
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4-2-movement-into-and-out-of-cells AS comparing-osmosis-in-plants-and-animals
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5-the-mitotic-cell-cycle8 主题
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5-2-chromosome-behaviour-in-mitosis AS observing-mitosis
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5-2-chromosome-behaviour-in-mitosis AS the-stages-of-mitosis
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5-1-replication-and-division-of-nuclei-and-cells AS how-tumours-form
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5-1-replication-and-division-of-nuclei-and-cells AS the-role-of-stem-cells
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5-1-replication-and-division-of-nuclei-and-cells AS the-role-of-telomeres-
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5-1-replication-and-division-of-nuclei-and-cells AS the-cell-cycle
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5-1-replication-and-division-of-nuclei-and-cells AS mitosis
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5-1-replication-and-division-of-nuclei-and-cells AS chromosome-structure
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5-2-chromosome-behaviour-in-mitosis AS observing-mitosis
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6-nucleic-acids-and-protein-synthesis9 主题
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6-2-protein-synthesis AS gene-mutations
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6-2-protein-synthesis AS transcription
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6-2-protein-synthesis AS constructing-polypeptides
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6-2-protein-synthesis AS the-universal-genetic-code
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6-2-protein-synthesis AS from-gene-to-polypeptide
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6-1-structure-of-nucleic-acids-and-replication-of-dna AS the-structure-of-rna
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6-1-structure-of-nucleic-acids-and-replication-of-dna AS semi-conservative-dna-replication
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6-1-structure-of-nucleic-acids-and-replication-of-dna AS the-structure-of-dna
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6-1-structure-of-nucleic-acids-and-replication-of-dna AS nucleotides
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6-2-protein-synthesis AS gene-mutations
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7-transport-in-plants11 主题
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7-2-transport-mechanisms AS phloem-mass-flow
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7-2-transport-mechanisms AS the-sucrose-loading-mechanism
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7-2-transport-mechanisms AS movement-in-the-phloem
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7-2-transport-mechanisms AS xerophytic-plant-leaf-adaptations
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7-2-transport-mechanisms AS water-and-the-transpiration-pull
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7-2-transport-mechanisms AS transpiration-in-plants
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7-2-transport-mechanisms AS water-and-mineral-ion-transport-in-plants
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7-1-structure-of-transport-tissues AS phloem-sieve-tube-elements
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7-1-structure-of-transport-tissues AS xylem-vessels-elements
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7-1-structure-of-transport-tissues AS xylem-and-phloem-distribution
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7-1-structure-of-transport-tissues AS plant-transverse-sections
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7-2-transport-mechanisms AS phloem-mass-flow
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8-transport-in-mammals16 主题
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8-3-the-heart AS heart-action
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8-3-the-heart AS the-cardiac-cycle
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8-3-the-heart AS the-walls-of-the-heart
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8-3-the-heart AS structure-of-the-heart
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8-2-transport-of-oxygen-and-carbon-dioxide AS the-bohr-shift
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8-2-transport-of-oxygen-and-carbon-dioxide AS the-oxygen-dissociation-curve
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8-2-transport-of-oxygen-and-carbon-dioxide AS plasma-and-carbon-dioxide
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8-2-transport-of-oxygen-and-carbon-dioxide AS the-chloride-shift
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8-2-transport-of-oxygen-and-carbon-dioxide AS red-blood-cells-haemoglobin-and-oxygen
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8-1-the-circulatory-system AS blood-tissue-fluid-and-lymph
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8-1-the-circulatory-system AS the-role-of-water-in-circulation
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8-1-the-circulatory-system AS cells-of-the-blood
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8-1-the-circulatory-system AS blood-vessels-structures-and-functions
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8-1-the-circulatory-system AS observing-and-drawing-blood-vessels
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8-1-the-circulatory-system AS the-main-blood-vessels
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8-1-the-circulatory-system AS circulatory-systems
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8-3-the-heart AS heart-action
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9-gas-exchange6 主题
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9-1-the-gas-exchange-system AS gas-exchange-processes
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9-1-the-gas-exchange-system AS structures-and-functions-of-the-gas-exchange-system
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9-1-the-gas-exchange-system AS recognising-structures
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9-1-the-gas-exchange-system AS recognising-tissues
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9-1-the-gas-exchange-system AS distribution-of-tissues
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9-1-the-gas-exchange-system AS the-human-gas-exchange-system
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9-1-the-gas-exchange-system AS gas-exchange-processes
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10-infectious-diseases6 主题
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11-immunity10 主题
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11-2-antibodies-and-vaccination AS vaccination-to-control-disease
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11-2-antibodies-and-vaccination AS how-vaccines-work
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11-2-antibodies-and-vaccination AS types-of-immunity
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11-2-antibodies-and-vaccination AS uses-of-monoclonal-antibodies
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11-2-antibodies-and-vaccination AS making-monoclonal-antibodies
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11-2-antibodies-and-vaccination AS antibodies
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11-1-the-immune-system AS memory-cells-and-immunity
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11-1-the-immune-system AS primary-immune-response
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11-1-the-immune-system AS antigens
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11-1-the-immune-system AS phagocytes
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11-2-antibodies-and-vaccination AS vaccination-to-control-disease
9-1-the-gas-exchange-system AS the-human-gas-exchange-system
Exam code:9700
The human gas exchange system
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Gas exchange takes place in the human thorax
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This is a collection of organs and tissues in the chest cavity
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Structure in thorax |
Description |
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Lungs |
Humans have two lungs, both of which are a central part of the breathing system and where gas exchange takes place |
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Trachea |
This airway leads from the mouth and nose to the bronchi The trachea is lined with mucus-secreting goblet cells and cilia The cilia sweep microorganisms and dust away from the lungs |
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Bronchi |
“Bronchi” is the plural of “bronchus” The left and right bronchi are at the bottom of the trachea and are similar in structure, but narrower The bronchi lead to bronchioles |
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Bronchioles |
These are narrow tubes (less than 1mm) which carry air from the bronchi to the alveoli |
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Alveoli |
The main site of gas exchange within the lungs These are tiny sacs with many structural adaptations to enable efficient gas exchange, such as their thin walls and large surface area to volume ratio |
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Capillary network |
An extensive network of capillaries surrounds the alveoli They are an exchange surface between the lungs and the blood During gas exchange, oxygen diffuses from the alveoli and into the capillaries, while carbon dioxide diffuses the other way and is exhaled |
Examiner Tips and Tricks
Remember to pay attention to command words in exams, as they will be asking different things. For example, a question asking you to “Describe” the structure of the alveoli is different from a question asking you to “Explain” the structure of the alveoli. “Describe” questions are asking you to give an account of something or to write events or processes in a logical order. “Explain” questions are asking you to write why something happens or to link its structure to its function—as a result of this, “because” will be an important part of your answer.
Responses