Key term
Edexcel GCSE Combined Science Biology 1SC0
Key Concepts in Biology
Topic overviewEukaryotic and prokaryotic cellsSpecialised cells and their adaptationsMicroscopes and magnification calculationsSize, scale and units in cell biologyEnzyme action and denaturationFactors affecting enzyme activityEnzymes in synthesis and digestion, and rate calculationsDiffusion, osmosis and active transportOsmosis in potatoes and percentage change in mass
Cells and Control
Genetics
Topic overviewMeiosis and the formation of gametesDNA structure, genes and the genomeExtracting DNA from fruitAlleles, genotype and phenotypeMonohybrid crosses and sex determinationProbability and ratios from genetic crossesCauses of variation: genes and environmentThe Human Genome ProjectGenetic variation and the effects of mutation
Natural Selection and Genetic Modification
Health, Disease and the Development of Medicines
Topic overviewHealth, disease and susceptibilityPathogens and common infectionsHow pathogens spread, and the virus life cycleSexually transmitted infectionsPhysical barriers and chemical defencesThe immune system, immunisation and herd immunityAntibiotics and developing new medicinesLifestyle factors and non-communicable diseaseTreatments for cardiovascular disease
Plant Structures and Their Functions
Animal Coordination, Control and Homeostasis
Exchange and Transport in Animals
Topic overviewWhy multicellular organisms need exchange surfacesAlveoli and gas exchangeThe blood and its componentsArteries, veins and capillariesThe heart and the circulatory systemCellular respiration as an exothermic reactionAerobic and anaerobic respiration comparedInvestigating the rate of respirationCardiac output, stroke volume and heart rate
Ecosystems and Material Cycles
Key Concepts in Biology
- 9 subtopics
- 27 things to know
- Papers 1 and 2
What Key Concepts in Biology covers
Key Concepts in Biology is examined in both biology papers, Paper 1 and Paper 2, as the key concepts that run through the whole course. It covers eukaryotic and prokaryotic cells, specialised cells, microscopy and magnification, size, scale and units, enzyme action, denaturation and the factors affecting enzyme activity, enzymes in synthesis and digestion with rate calculations, diffusion, osmosis and active transport, and the potato osmosis practical with percentage change in mass.
Where it is assessed
Papers 1 and 2
Key concepts, examined on both biology papers.
Check the Pearson Edexcel specification ↗The 9 subtopics
Each one has its own page.
- Eukaryotic and prokaryotic cellsWhat makes a cell eukaryotic, the functions of the nucleus, partially permeable membrane, mitochondria and ribosomes, how the cellulose cell wall, chloroplasts and permanent vacuole suit plant cells, and the circular chromosomal DNA, plasmids, flagellum and smaller ribosomes of a bacterium.Open →
- Specialised cells and their adaptationsWhat a specialised cell is, how the acrosome, haploid nucleus, mitochondria and tail adapt a sperm cell, the nutrient store and membrane change of an egg cell, and how the cilia of ciliated epithelial cells sweep mucus away from the lungs.Open →
- Microscopes and magnification calculationsMagnification and resolution, why electron microscopes resolve finer detail and what they revealed, preparing, staining and focusing an onion slide, total magnification, the magnification equation and calculating actual size in micrometres, rules for scientific drawings, and reducing error when measuring cells.Open →
- Size, scale and units in cell biologyTypical sizes of bacterial and animal cells, orders of magnitude and when to estimate, the prefixes milli, micro, nano and pico, converting sizes to metres in standard form and calculating size ratios and magnification from them, and the symbols for much less than, much greater than, approximately and proportional to.Open →
- Enzyme action and denaturationEnzymes as biological catalysts, the active site and substrate, specificity and the lock and key model, lowering the energy needed to start a reaction, and how high temperature and extreme pH permanently denature an enzyme so its substrate no longer fits.Open →
- Factors affecting enzyme activityHow temperature, substrate concentration and pH affect enzyme activity, optimum temperature and pH, the amylase and starch investigation with buffers, iodine and a water bath, its variables, errors and results, and accuracy, precision, repeatability, reproducibility, and random and systematic errors.Open →
- Enzymes in synthesis and digestion, and rate calculationsCalculating rate as 1 divided by time and as volume per unit time, comparing rates, carbohydrases, proteases and lipases and their products, enzymes building carbohydrates, proteins and lipids, and giving calculated answers to an appropriate number of significant figures.Open →
- Diffusion, osmosis and active transportDiffusion as net movement down a concentration gradient without energy, the factors that increase its rate, osmosis through a partially permeable membrane and water entering root hair cells, and active transport against a gradient using carrier proteins and energy from respiration to take up mineral ions.Open →
- Osmosis in potatoes and percentage change in massPreparing and blotting potato cylinders and the variables in the osmosis investigation, why tissue gains or loses mass, calculating percentage change in mass and final mass, using repeats and means, and writing up an investigation from aim and hypothesis to conclusion and evaluation, and other ways to communicate findings.Open →
What you need to know
Answer each one before you reveal it.
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Define osmosis and active transport, and describe how water crosses the membrane of a root hair cell.
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Name two types of organism whose cells are eukaryotic.
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What is a specialised cell?
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What is meant by the magnification of a microscope?
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State a typical diameter for a bacterial cell.
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Describe the effect of raising the temperature on enzyme activity below the optimum.
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How is the rate of an enzyme-controlled reaction calculated from the time taken for a reaction to finish?
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Describe how potato cylinders are prepared for an investigation into osmosis.
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Explain why muscle cells contain very large numbers of mitochondria.
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Describe the function of the acrosome in a sperm cell.
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What is meant by the resolution of a microscope?
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State a typical width for an animal cell such as a cheek cell.
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What is meant by the substrate of an enzyme?
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Explain the shape of a graph of enzyme activity against temperature above the optimum.
Numbers
Starch is fully broken down in 40 seconds. Calculate the rate of reaction.
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Define diffusion.
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Identify the independent and dependent variables in an investigation into osmosis in potatoes.
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State the function of ribosomes.
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Explain why a sperm cell contains many mitochondria in the middle section.
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Explain why an electron microscope has a much higher resolution than a light microscope.
Numbers
Roughly how many times wider is a typical animal cell than a typical bacterium?
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Explain why each enzyme will only work on one type of substrate.
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Describe how enzyme activity changes as substrate concentration is increased from zero.
Numbers
An enzyme releases 24 cm³ of oxygen in 30 seconds. Calculate the mean rate of oxygen production.
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Explain why diffusion does not require the cell to use energy.
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Name three variables that must be controlled in an investigation into osmosis in potatoes.
Take Key Concepts in Biology further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Osmosis vs Active transport
Osmosis: water moving from a dilute to a concentrated solution across a membrane. Active transport: moving a substance against its gradient using energy from respiration.
Magnification vs Resolution
Magnification: how many times larger an image appears than the real specimen. Resolution: smallest distance between two points still seen as separate.
Active site vs Substrate
Active site: pocket on the enzyme surface where the reaction takes place. Substrate: molecule that the enzyme acts on and changes into products.
Questions from this topic
Each one with the model answer underneath.
- 1
What is the defining feature of a eukaryotic cell?
Model answer
Its genetic material is enclosed inside a nucleus surrounded by a membrane.
- 2
Name two types of organism whose cells are eukaryotic.
Model answer
Animals and plants both have eukaryotic cells.
- 3
State the function of the nucleus in an animal cell.
Model answer
It contains the chromosomal DNA that controls the activities of the cell.
- 4
Explain why a cell membrane is described as partially permeable.
Model answer
It lets some substances pass into and out of the cell while holding others back, so it controls what enters and leaves.
- 5
Explain why muscle cells contain very large numbers of mitochondria.
Model answer
Mitochondria are the site of aerobic respiration, and contracting muscle needs a large and continuous supply of energy.
- 6
State the function of ribosomes.
Model answer
Ribosomes are where amino acids are joined together to make proteins.
What is inside Levo
Six ways to work the same material.
Key Concepts in Biology revision questions
- What does Key Concepts in Biology cover in Edexcel GCSE Combined Science Biology?
- 9 subtopics: eukaryotic and prokaryotic cells, specialised cells and their adaptations, microscopes and magnification calculations, size, scale and units in cell biology, enzyme action and denaturation, factors affecting enzyme activity, enzymes in synthesis and digestion, and rate calculations, diffusion, osmosis and active transport and osmosis in potatoes and percentage change in mass. Each one has its own page with questions and model answers.
- How is Key Concepts in Biology organised?
- By the Edexcel 1SC0 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Key Concepts in Biology, on a schedule.
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