Biology AS OCR
-
1-1-practical-skills-written-assessment AS7 主题
-
1-2-practical-skills-endorsement-assessment AS16 主题
-
1-2-1-practical-ethical-use-of-organisms as
-
1-2-2-practical-aseptic-techniques as
-
1-2-3-practical-dissection-of-gas-exchange-surfaces-in-fish-and-insects as
-
1-2-4-drawing-cells-from-blood-smears as
-
1-2-5-practical-investigating-biodiversity-using-sampling as
-
1-2-6-practical-data-loggers-and-computer-modelling as
-
1-2-7-practical-investigating-the-rate-of-diffusion as
-
1-2-8-practical-investigating-water-potential as
-
1-2-9-practical-factors-affecting-membrane-structure-and-permeability as
-
1-2-10-biochemical-tests-reducing-sugars-and-starch as
-
1-2-11-biochemical-tests-lipids as
-
1-2-12-biochemical-tests-proteins as
-
1-2-13-chromatography as
-
1-2-14-serial-dilutions as
-
1-2-15-practical-investigating-the-rate-of-transpiration as
-
1-2-16-practical-using-a-light-microscope as
-
1-2-1-practical-ethical-use-of-organisms as
-
2-1-cell-structure AS9 主题
-
2-1-2-using-a-microscope as
-
2-1-3-drawing-cells as
-
2-1-4-magnification-and-resolution as
-
2-1-5-eukaryotic-cells as
-
2-1-6-eukaryotic-cells-under-the-microscope as
-
2-1-7-organelles-and-the-production-of-proteins as
-
2-1-8-the-cytoskeleton as
-
2-1-9-prokaryotic-and-eukaryotic-cells as
-
2-1-1-studying-cells as
-
2-1-2-using-a-microscope as
-
2-2-biological-molecules AS17 主题
-
2-2-1-properties-of-water as
-
2-2-2-monomers-and-polymers as
-
2-2-3-monosaccharides as
-
2-2-4-the-glycosidic-bond as
-
2-2-5-polysaccharides as
-
2-2-6-biochemical-tests-reducing-sugars-and-starch as
-
2-2-7-lipids-and-ester-bonds as
-
2-2-8-lipids-structure-and-function as
-
2-2-9-biochemical-tests-lipids as
-
2-2-10-amino-acids-and-peptide-bonds as
-
2-2-11-protein-structure as
-
2-2-12-globular-proteins as
-
2-2-13-fibrous-proteins as
-
2-2-14-inorganic-ions as
-
2-2-15-biochemical-tests-proteins as
-
2-2-16-finding-the-concentration-of-a-substance as
-
2-2-17-chromatography as
-
2-2-1-properties-of-water as
-
2-3-nucleotides-and-nucleic-acids AS8 主题
-
2-4-enzymes AS9 主题
-
2-4-1-the-role-of-enzymes as
-
2-4-2-enzyme-action as
-
2-4-3-enzyme-activity-ph as
-
2-4-4-enzyme-activity-temperature as
-
2-4-5-enzyme-activity-enzyme-concentration as
-
2-4-6-enzyme-activity-substrate-concentration as
-
2-4-7-enzyme-activity-enzyme-inhibitors as
-
2-4-8-coenzymes-cofactors-and-prosthetic-groups as
-
2-4-9-practical-measuring-enzyme-activity as
-
2-4-1-the-role-of-enzymes as
-
2-5-biological-membranes AS9 主题
-
2-5-1-the-cell-surface-membrane as
-
2-5-2-membrane-structure-and-permeability as
-
2-5-3-diffusion-and-facilitated-diffusion as
-
2-5-4-practical-investigating-the-rate-of-diffusion as
-
2-5-5-active-transport as
-
2-5-6-endocytosis-and-exocytosis as
-
2-5-7-osmosis as
-
2-5-8-osmosis-in-animal-and-plant-cells as
-
2-5-9-practical-investigating-water-potential as
-
2-5-1-the-cell-surface-membrane as
-
2-6-cell-division-cell-diversity-and-cellular-organisation AS11 主题
-
2-6-1-the-cell-cycle as
-
2-6-2-the-stages-of-mitosis as
-
2-6-3-identifying-mitosis-in-plant-cells as
-
2-6-4-the-significance-of-mitosis as
-
2-6-5-the-stages-of-meiosis as
-
2-6-6-the-significance-of-meiosis as
-
2-6-7-specialised-cells as
-
2-6-8-the-organisation-of-cells as
-
2-6-9-stem-cells as
-
2-6-10-stem-cells-in-animals-and-plants as
-
2-6-11-the-use-of-stem-cells as
-
2-6-1-the-cell-cycle as
-
3-1-exchange-surfaces AS7 主题
-
3-2-transport-in-animals AS12 主题
-
3-2-1-the-need-for-transport-systems-in-animals as
-
3-2-2-circulatory-systems as
-
3-2-3-blood-vessels as
-
3-2-4-tissue-fluid as
-
3-2-5-the-mammalian-heart as
-
3-2-6-practical-mammalian-heart-dissection as
-
3-2-7-the-cardiac-cycle as
-
3-2-8-cardiac-output as
-
3-2-9-heart-action-initiation-and-control as
-
3-2-10-electrocardiograms-ecgs as
-
3-2-11-the-role-of-haemoglobin as
-
3-2-12-adult-and-fetal-haemoglobin as
-
3-2-1-the-need-for-transport-systems-in-animals as
-
3-3-transport-in-plants AS11 主题
-
3-3-1-the-need-for-transport-systems-in-plants as
-
3-3-2-the-xylem-and-phloem as
-
3-3-3-the-xylem as
-
3-3-4-the-phloem as
-
3-3-5-transverse-sections-stems-roots-and-leaves as
-
3-3-6-the-process-of-transpiration as
-
3-3-7-transpiration-in-plants as
-
3-3-8-practical-investigating-the-rate-of-transpiration as
-
3-3-9-translocation as
-
3-3-10-the-mass-flow-hypothesis as
-
3-3-11-the-adaptations-of-xerophytic-and-hydrophytic-plants as
-
3-3-1-the-need-for-transport-systems-in-plants as
-
4-1-communicable-diseases-disease-prevention-and-the-immune-system AS16 主题
-
4-1-1-common-pathogens-and-communicable-diseases as
-
4-1-2-transmission-of-communicable-pathogens as
-
4-1-3-plant-defences-against-pathogens as
-
4-1-4-non-specific-immune-responses as
-
4-1-5-phagocytes as
-
4-1-6-blood-cells as
-
4-1-7-the-t-lymphocyte-response as
-
4-1-8-the-b-lymphocyte-response as
-
4-1-9-primary-and-secondary-immune-responses as
-
4-1-10-antibodies as
-
4-1-11-opsonins-agglutinins-and-anti-toxins as
-
4-1-12-types-of-immunity as
-
4-1-13-autoimmune-diseases as
-
4-1-14-principles-of-vaccination as
-
4-1-15-sources-of-medicine as
-
4-1-16-antibiotics as
-
4-1-1-common-pathogens-and-communicable-diseases as
-
4-2-biodiversity AS10 主题
-
4-2-1-biodiversity as
-
4-2-2-sampling-to-determine-biodiversity as
-
4-2-3-practical-investigating-biodiversity-using-sampling as
-
4-2-4-measuring-species-richness-and-species-evenness as
-
4-2-5-simpsons-index as
-
4-2-6-genetic-diversity as
-
4-2-7-factors-affecting-biodiversity as
-
4-2-8-reasons-for-maintaining-biodiversity as
-
4-2-9-methods-of-maintaining-biodiversity as
-
4-2-10-conservation-agreements as
-
4-2-1-biodiversity as
-
4-3-classification-and-evolution AS15 主题
-
4-3-1-classification-of-species as
-
4-3-2-binomial-system as
-
4-3-3-classification-of-the-three-domains as
-
4-3-4-classification-of-the-five-kingdoms as
-
4-3-5-classification-and-phylogeny as
-
4-3-6-evidence-of-evolution as
-
4-3-7-types-of-variation as
-
4-3-8-standard-deviation as
-
4-3-9-variation-t-test-method as
-
4-3-10-variation-t-test-worked-example as
-
4-3-11-spearmans-rank-correlation as
-
4-3-12-adaptation as
-
4-3-13-natural-selection as
-
4-3-14-evolution-of-resistance as
-
4-3-15-consequences-of-resistance as
-
4-3-1-classification-of-species as
2-1-9-prokaryotic-and-eukaryotic-cells as
Exam code:H020
Comparison of Prokaryotic & Eukaryotic Cells
-
Animal and plant cells are types of eukaryotic cells, whereas bacteria are a type of prokaryote
-
Prokaryotic cells are much smaller than eukaryotic cells (between 100 – 1000 times smaller)
-
Prokaryotic cells also differ from eukaryotic cells in having:
-
A cytoplasm that lacks membrane-bound organelles
-
Their ribosomes are structurally smaller (70 S) in comparison to those found in eukaryotic cells (80 S)
-
No nucleus (instead they have a single circular DNA molecule that is free in the cytoplasm and is not associated with proteins)
-
A cell wall that contains murein (a glycoprotein)
-
-
In addition, many prokaryotic cells have a few other structures that differentiate them from others and act as a selective advantage, examples of these are:
-
Plasmids
-
Capsules
-
Flagellum
-
-
Plasmids are small loops of DNA that are separate from the main circular DNA molecule
-
Plasmids contain genes that can be passed between prokaryotes (e.g. genes for antibiotic resistance)
-
-
Some prokaryotes (e.g. bacteria) are surrounded by a final outer layer known as a capsule. This is sometimes called the slime capsule
-
It helps to protect bacteria from drying out and from attack by cells of the immune system of the host organism
-
-
Flagellum (plural = flagella) are long, tail-like structure that rotate, enabling the prokaryote to move (a bit like a propeller)
-
Some prokaryotes have more than one
-
Structures unique to prokaryotic cells
Prokaryotic cells are often described as being ‘simpler’ than eukaryotic cells, and they are believed to have emerged as the first living organisms on Earth.
-
There are a number of important structural and physiological differences between prokaryotic and eukaryotic cells
-
These differences affect their metabolic processes and how they reproduce
-
Prokaryotic & Eukaryotic Cells Comparison Table
Examiner Tips and Tricks
You will need to know all the differences between prokaryotic and eukaryotic cells. Remember – the features in the table above are not present in all prokaryotes so keep this in mind when answering exam questions. Also, 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.
Responses