Biology_Edexcel_A-snab_Alevel
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the-circulatory-system8 主题
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diet-and-health11 主题
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gas-exchange-cell-membranes-and-transport8 主题
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nucleic-acids3 主题
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proteins10 主题
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inheritance7 主题
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cell-structure-and-organisation7 主题
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cell-division3 主题
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reproduction-and-inheritance4 主题
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differentiation-and-variation5 主题
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biodiversity9 主题
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resources-from-plants10 主题
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plant-cell-structure
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plant-stems
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importance-of-water-and-inorganic-ions-to-plants
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starch-and-cellulose-structure-and-function
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plant-fibres
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practical-identifying-tissue-types-within-stems
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tensile-strength-plant-fibres
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development-of-drug-testing
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antimicrobial-properties-of-plants
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sustainability-and-plant-materials
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plant-cell-structure
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ecosystems-and-energy-transfer7 主题
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photosynthesis7 主题
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climate-change10 主题
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the-effects-of-climate-change
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temperature-and-enzyme-activity
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practical-temperature-and-development-of-organisms
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climate-change-and-the-scientific-community
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carbon-cycle-and-reduction-of-atmospheric-carbon-dioxide
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reducing-climate-change
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introduction-to-climate-change
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evidence-for-the-causes-of-climate-change
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the-greenhouse-effect
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models-of-future-climate-change
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the-effects-of-climate-change
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evolution3 主题
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forensics3 主题
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microorganisms-and-immunity11 主题
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muscles-and-movement3 主题
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respiration7 主题
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homeostasis4 主题
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exercise4 主题
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response-to-the-environment8 主题
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the-brain-behaviour-and-disease10 主题
prokaryotic-cells
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.