Biology AS Edexcel Snab Revision
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lifestyle-health-and-risk as19 主题
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diet-and-health interpreting-data-on-risk-factors
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diet-and-health treatment-of-cvd
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diet-and-health energy-budgets-and-diet
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diet-and-health monosaccharides
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diet-and-health the-glycosidic-bond
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diet-and-health disaccharides
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diet-and-health polysaccharides
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diet-and-health lipids-and-ester-bonds
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diet-and-health reducing-risk-factors-of-cvd
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diet-and-health practical-vitamin-c-content
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the-circulatory-system the-need-for-a-circulatory-system
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the-circulatory-system the-importance-of-water-in-transport
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the-circulatory-system mammalian-heart-structure-and-function
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the-circulatory-system blood-vessels-structure-and-function
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the-circulatory-system cardiac-cycle
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the-circulatory-system investigating-heart-rate
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the-circulatory-system atherosclerosis
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the-circulatory-system blood-clotting
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diet-and-health cardiovascular-disease
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diet-and-health interpreting-data-on-risk-factors
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genes-and-health as28 主题
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gas-exchange-cell-membranes-and-transport properties-of-gas-exchange-surfaces
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gas-exchange-cell-membranes-and-transport ficks-law-of-diffusion
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gas-exchange-cell-membranes-and-transport the-mammalian-lung
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gas-exchange-cell-membranes-and-transport cell-membranes
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gas-exchange-cell-membranes-and-transport practical-investigating-membrane-permeability
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gas-exchange-cell-membranes-and-transport diffusion-and-facilitated-diffusion
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gas-exchange-cell-membranes-and-transport active-transport
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gas-exchange-cell-membranes-and-transport osmosis
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nucleic-acids nucleotides-and-phosphodiester-bonds
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nucleic-acids dna-structure
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nucleic-acids rna-structure
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proteins transcription
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proteins translation
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proteins nature-of-the-genetic-code
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proteins amino-acids-and-peptide-bonds
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proteins levels-of-protein-structure
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proteins globular-proteins-structure-and-function
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proteins fibrous-proteins-structure-and-function
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proteins the-role-of-enzymes
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proteins mode-of-enzyme-action
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proteins enzyme-and-substrate-concentrations
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inheritance dna-replication
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inheritance mutations
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inheritance inheritance-key-terms
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inheritance pedigree-diagrams
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inheritance monohybrid-crosses
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inheritance chi-squared-test
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inheritance genetic-screening
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gas-exchange-cell-membranes-and-transport properties-of-gas-exchange-surfaces
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voice-of-the-genome as19 主题
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cell-structure-and-organisation cell-theory
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cell-structure-and-organisation eukaryotic-cells
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cell-structure-and-organisation prokaryotic-cells
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cell-structure-and-organisation organisation-of-cells
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cell-structure-and-organisation microscopy
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cell-structure-and-organisation magnification-calculations
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cell-structure-and-organisation recognising-organelles
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cell-division the-cell-cycle
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cell-division mitosis
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cell-division practical-identifying-mitosis-in-plant-cells
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reproduction-and-inheritance mammalian-gametes
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reproduction-and-inheritance fertilisation-in-mammals
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reproduction-and-inheritance genes-and-linkage
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reproduction-and-inheritance meiosis-source-of-genetic-variation
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differentiation-and-variation stem-cells
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differentiation-and-variation stem-cells-in-medicine
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differentiation-and-variation cell-differentiation
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differentiation-and-variation epigenetics
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differentiation-and-variation phenotypes-and-variation
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cell-structure-and-organisation cell-theory
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biodiversity-and-natural-resources as19 主题
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biodiversity the-variety-of-life
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biodiversity measuring-biodiversity-within-a-habitat
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biodiversity comparing-biodiversity-between-habitats
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biodiversity ecological-niches-and-adaptations
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biodiversity natural-selection
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biodiversity hardy-weinberg-equation
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biodiversity reproductive-isolation
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biodiversity classification
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biodiversity conservation-of-biodiversity
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resources-from-plants plant-cell-structure
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resources-from-plants plant-stems
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resources-from-plants importance-of-water-and-inorganic-ions-to-plants
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resources-from-plants starch-and-cellulose-structure-and-function
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resources-from-plants plant-fibres
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resources-from-plants practical-identifying-tissue-types-within-stems
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resources-from-plants tensile-strength-plant-fibres
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resources-from-plants development-of-drug-testing
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resources-from-plants antimicrobial-properties-of-plants
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resources-from-plants sustainability-and-plant-materials
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biodiversity the-variety-of-life
cell-structure-and-organisation prokaryotic-cells
Exam code:8BN0
Prokaryotic Cells: Structure
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Animal and plant cells are types of eukaryotic cells, whereas bacteria are a type of prokaryote
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Prokaryotic cells are much smaller than eukaryotic cells
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They also differ from eukaryotic cells in having
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A cytoplasm that lacks membrane-bound organelles
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Ribosomes that are smaller (70 S) than those found in eukaryotic cells (80 S)
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No nucleus, instead having a single circular bacterial chromosome that is free in the cytoplasm and is not associated with proteins
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A cell wall that contains the glycoprotein murein
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Murein is sometimes known as peptidoglycan
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In addition, many prokaryotic cells also have the following structures
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Loops of DNA known as plasmids
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Capsules
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Flagella (singular flagellum)
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Pili (singular pilus)
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A cell membrane that contains folds known as mesosomes
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Additional Prokaryotic Structures Table


Bacteria are prokaryotic cells
Prokaryotes vs eukaryotes
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There are a number of important structural and physiological differences between prokaryotic and eukaryotic cells
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These differences affect their metabolic processes and how they reproduce
Comparison of Prokaryotic and Eukaryotic Cells Table

Examiner Tips and Tricks
You will need to know all the differences between prokaryotic and eukaryotic cells; remember that not all of the structures mentioned here are present in all prokaryotic cells
Remember that size is not a structural feature so if you are asked for a structural difference between a prokaryotic and eukaryotic cell don’t include size in your answer.
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