Biology AS OCR
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1-1-practical-skills-written-assessment AS7 主题
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1-2-practical-skills-endorsement-assessment AS16 主题
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1-2-1-practical-ethical-use-of-organisms as
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1-2-2-practical-aseptic-techniques as
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1-2-3-practical-dissection-of-gas-exchange-surfaces-in-fish-and-insects as
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1-2-4-drawing-cells-from-blood-smears as
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1-2-5-practical-investigating-biodiversity-using-sampling as
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1-2-6-practical-data-loggers-and-computer-modelling as
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1-2-7-practical-investigating-the-rate-of-diffusion as
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1-2-8-practical-investigating-water-potential as
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1-2-9-practical-factors-affecting-membrane-structure-and-permeability as
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1-2-10-biochemical-tests-reducing-sugars-and-starch as
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1-2-11-biochemical-tests-lipids as
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1-2-12-biochemical-tests-proteins as
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1-2-13-chromatography as
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1-2-14-serial-dilutions as
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1-2-15-practical-investigating-the-rate-of-transpiration as
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1-2-16-practical-using-a-light-microscope as
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1-2-1-practical-ethical-use-of-organisms as
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2-1-cell-structure AS9 主题
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2-1-2-using-a-microscope as
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2-1-3-drawing-cells as
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2-1-4-magnification-and-resolution as
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2-1-5-eukaryotic-cells as
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2-1-6-eukaryotic-cells-under-the-microscope as
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2-1-7-organelles-and-the-production-of-proteins as
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2-1-8-the-cytoskeleton as
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2-1-9-prokaryotic-and-eukaryotic-cells as
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2-1-1-studying-cells as
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2-1-2-using-a-microscope as
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2-2-biological-molecules AS17 主题
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2-2-1-properties-of-water as
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2-2-2-monomers-and-polymers as
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2-2-3-monosaccharides as
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2-2-4-the-glycosidic-bond as
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2-2-5-polysaccharides as
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2-2-6-biochemical-tests-reducing-sugars-and-starch as
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2-2-7-lipids-and-ester-bonds as
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2-2-8-lipids-structure-and-function as
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2-2-9-biochemical-tests-lipids as
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2-2-10-amino-acids-and-peptide-bonds as
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2-2-11-protein-structure as
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2-2-12-globular-proteins as
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2-2-13-fibrous-proteins as
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2-2-14-inorganic-ions as
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2-2-15-biochemical-tests-proteins as
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2-2-16-finding-the-concentration-of-a-substance as
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2-2-17-chromatography as
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2-2-1-properties-of-water as
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2-3-nucleotides-and-nucleic-acids AS8 主题
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2-4-enzymes AS9 主题
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2-4-1-the-role-of-enzymes as
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2-4-2-enzyme-action as
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2-4-3-enzyme-activity-ph as
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2-4-4-enzyme-activity-temperature as
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2-4-5-enzyme-activity-enzyme-concentration as
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2-4-6-enzyme-activity-substrate-concentration as
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2-4-7-enzyme-activity-enzyme-inhibitors as
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2-4-8-coenzymes-cofactors-and-prosthetic-groups as
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2-4-9-practical-measuring-enzyme-activity as
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2-4-1-the-role-of-enzymes as
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2-5-biological-membranes AS9 主题
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2-5-1-the-cell-surface-membrane as
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2-5-2-membrane-structure-and-permeability as
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2-5-3-diffusion-and-facilitated-diffusion as
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2-5-4-practical-investigating-the-rate-of-diffusion as
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2-5-5-active-transport as
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2-5-6-endocytosis-and-exocytosis as
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2-5-7-osmosis as
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2-5-8-osmosis-in-animal-and-plant-cells as
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2-5-9-practical-investigating-water-potential as
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2-5-1-the-cell-surface-membrane as
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2-6-cell-division-cell-diversity-and-cellular-organisation AS11 主题
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2-6-1-the-cell-cycle as
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2-6-2-the-stages-of-mitosis as
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2-6-3-identifying-mitosis-in-plant-cells as
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2-6-4-the-significance-of-mitosis as
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2-6-5-the-stages-of-meiosis as
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2-6-6-the-significance-of-meiosis as
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2-6-7-specialised-cells as
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2-6-8-the-organisation-of-cells as
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2-6-9-stem-cells as
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2-6-10-stem-cells-in-animals-and-plants as
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2-6-11-the-use-of-stem-cells as
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2-6-1-the-cell-cycle as
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3-1-exchange-surfaces AS7 主题
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3-2-transport-in-animals AS12 主题
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3-2-1-the-need-for-transport-systems-in-animals as
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3-2-2-circulatory-systems as
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3-2-3-blood-vessels as
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3-2-4-tissue-fluid as
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3-2-5-the-mammalian-heart as
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3-2-6-practical-mammalian-heart-dissection as
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3-2-7-the-cardiac-cycle as
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3-2-8-cardiac-output as
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3-2-9-heart-action-initiation-and-control as
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3-2-10-electrocardiograms-ecgs as
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3-2-11-the-role-of-haemoglobin as
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3-2-12-adult-and-fetal-haemoglobin as
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3-2-1-the-need-for-transport-systems-in-animals as
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3-3-transport-in-plants AS11 主题
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3-3-1-the-need-for-transport-systems-in-plants as
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3-3-2-the-xylem-and-phloem as
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3-3-3-the-xylem as
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3-3-4-the-phloem as
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3-3-5-transverse-sections-stems-roots-and-leaves as
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3-3-6-the-process-of-transpiration as
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3-3-7-transpiration-in-plants as
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3-3-8-practical-investigating-the-rate-of-transpiration as
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3-3-9-translocation as
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3-3-10-the-mass-flow-hypothesis as
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3-3-11-the-adaptations-of-xerophytic-and-hydrophytic-plants as
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3-3-1-the-need-for-transport-systems-in-plants as
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4-1-communicable-diseases-disease-prevention-and-the-immune-system AS16 主题
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4-1-1-common-pathogens-and-communicable-diseases as
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4-1-2-transmission-of-communicable-pathogens as
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4-1-3-plant-defences-against-pathogens as
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4-1-4-non-specific-immune-responses as
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4-1-5-phagocytes as
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4-1-6-blood-cells as
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4-1-7-the-t-lymphocyte-response as
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4-1-8-the-b-lymphocyte-response as
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4-1-9-primary-and-secondary-immune-responses as
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4-1-10-antibodies as
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4-1-11-opsonins-agglutinins-and-anti-toxins as
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4-1-12-types-of-immunity as
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4-1-13-autoimmune-diseases as
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4-1-14-principles-of-vaccination as
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4-1-15-sources-of-medicine as
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4-1-16-antibiotics as
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4-1-1-common-pathogens-and-communicable-diseases as
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4-2-biodiversity AS10 主题
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4-2-1-biodiversity as
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4-2-2-sampling-to-determine-biodiversity as
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4-2-3-practical-investigating-biodiversity-using-sampling as
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4-2-4-measuring-species-richness-and-species-evenness as
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4-2-5-simpsons-index as
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4-2-6-genetic-diversity as
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4-2-7-factors-affecting-biodiversity as
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4-2-8-reasons-for-maintaining-biodiversity as
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4-2-9-methods-of-maintaining-biodiversity as
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4-2-10-conservation-agreements as
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4-2-1-biodiversity as
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4-3-classification-and-evolution AS15 主题
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4-3-1-classification-of-species as
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4-3-2-binomial-system as
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4-3-3-classification-of-the-three-domains as
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4-3-4-classification-of-the-five-kingdoms as
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4-3-5-classification-and-phylogeny as
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4-3-6-evidence-of-evolution as
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4-3-7-types-of-variation as
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4-3-8-standard-deviation as
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4-3-9-variation-t-test-method as
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4-3-10-variation-t-test-worked-example as
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4-3-11-spearmans-rank-correlation as
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4-3-12-adaptation as
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4-3-13-natural-selection as
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4-3-14-evolution-of-resistance as
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4-3-15-consequences-of-resistance as
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4-3-1-classification-of-species as
1-2-4-drawing-cells-from-blood-smears as
Exam code:H020
Drawing Cells From Blood Smears
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To record the observations seen under the microscope (or from photomicrographs taken) a labelled biological drawing is often made
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Biological drawings are line pictures which show specific features that have been observed when the specimen was viewed
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There are a number of rules/conventions that are followed when making a biological drawing
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The conventions are:
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The drawing must have a title
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The magnification under which the observations shown by the drawing are made must be recorded
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A sharp HB pencil should be used (and a good eraser!)
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Drawings should be on plain white paper
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Lines should be clear, single lines (no thick shading)
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No shading
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The drawing should take up as much of the space on the page as possible
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Well-defined structures should be drawn
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The drawing should be made with proper proportions
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Label lines should not cross or have arrowheads and should connect directly to the part of the drawing being labelled
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Label lines should be kept to one side of the drawing (in parallel to the top of the page) and drawn with a ruler
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Drawings of cells are typically made when visualizing cells at a higher magnification power, whereas plan drawings are typically made of tissues viewed under lower magnifications (individual cells are never drawn in a plan diagram)
Blood smears
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A blood smear is when a small amount of blood is spread on a glass microscope slide, stained and covered with a coverslip
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The different blood cells can then be examined using a microscope
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Red blood cells have no nuclei and a distinct biconcave shape
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White blood cells have irregular shapes
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Neutrophils have distinctive lobed nuclei
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They make up roughly 70% of all white blood cells
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Lymphocytes have very large nuclei that nearly occupy the entire cell
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The different blood cells present in a blood smear
The lobed nucleus of a neutrophil
An example drawing of the cells observed (using a microscope) in a blood smear
Examiner Tips and Tricks
When producing a biological drawing, it is vital that you only ever draw what you see and not what you think you see.To accurately reflect the size and proportions of structures you see under the microscope, you should get used to using the eyepiece graticule.You should be able to describe and interpret photomicrographs, electron micrographs and drawings of typical animal cells.
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