Tips
A-Level Biology (9700) starts at the cell and works outwards: membranes and transport, the mitotic cell cycle, nucleic acids and protein synthesis, then transport in plants and mammals, gas exchange, infectious disease and immunity. A2 adds respiration, photosynthesis, homeostasis, inheritance, selection and evolution.
Biology is called the memorising science, and that is exactly what catches people out. The command word does most of the work: "explain" wants a mechanism, "describe" does not. A perfect description scores nothing when the question said explain.
Answers are marked against specific scheme points. One vague sentence covering three ideas usually earns one mark, not three.
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1
Cell structure
Watch lesson- 1.1 How we study cells
- 1.2 Eukaryotic cells and their organelles
- 1.2 Prokaryotic cells (bacteria)
- 1.2 Viruses
- 1.2 Exam tips
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2
Biological molecules
Watch lesson- 2.1 Testing for biological molecules
- 2.2 Carbohydrates
- 2.2 Lipids
- 2.3 Proteins
- 2.4 Water
- 2.4 Exam tips
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3
Enzymes
Watch lesson- 3.1 What enzymes are
- 3.1 How enzymes work
- 3.1 Measuring the rate of a reaction
- 3.2 Factors that affect enzyme activity
- 3.2 V_max and the Michaelis–Menten constant
- 3.2 Reversible inhibitors
- 3.2 Immobilised enzymes
- 3.2 Exam tips
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4
Cell membranes and transport
Watch lesson- 4.1 The cell surface membrane
- 4.1 Cell signalling
- 4.2 Moving substances across the membrane
- 4.2 Surface area to volume ratio
- 4.2 Water potential and living cells
- 4.2 Exam tips
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5
The mitotic cell cycle
Watch lesson- 5.1 The structure of a chromosome
- 5.1 Why mitosis matters
- 5.1 The mitotic cell cycle
- 5.1 Telomeres and the ends of chromosomes
- 5.1 Stem cells
- 5.1 Uncontrolled division and tumours
- 5.2 The stages of mitosis
- 5.2 Exam tips
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6
Nucleic acids and protein synthesis
Watch lesson- 6.1 Nucleotides — the building blocks
- 6.1 The structure of DNA
- 6.1 DNA replication
- 6.1 RNA
- 6.2 The genetic code
- 6.2 Protein synthesis: transcription and translation
- 6.2 Gene mutations
- 6.2 Exam tips
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7
Transport in plants
Watch lesson- 7.1 The two transport tissues
- 7.2 Water from the soil to the xylem
- 7.2 Transpiration and the movement of water up the xylem
- 7.2 Xerophytes
- 7.2 Translocation: moving assimilates in the phloem
- 7.2 Exam tips
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8
Transport in mammals
Watch lesson- 8.1 The circulatory system
- 8.2 Transport of oxygen and carbon dioxide
- 8.3 The heart
- 8.3 Exam tips
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9
Gas exchange
Watch lesson- 9.1 The gas exchange system
- 9.1 The tissues of the airways and what they do
- 9.1 Gas exchange in the alveoli
- 9.1 Exam tips
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10
Infectious diseases
Watch lesson- 10.1 What causes infectious disease
- 10.1 Preventing and controlling these diseases
- 10.2 Antibiotics
- 10.2 Antibiotic resistance
- 10.2 Exam tips
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11
Immunity
Watch lesson- 11.1 Phagocytes — the first defence
- 11.1 Antigens: self and non-self
- 11.1 The primary immune response
- 11.1 Memory cells and long-term immunity
- 11.2 Antibodies
- 11.2 Monoclonal antibodies
- 11.2 Types of immunity
- 11.2 Vaccination
- 11.2 Exam tips
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12
Energy and respiration
Watch lesson- 12.1 Why living things need energy
- 12.1 ATP — the energy currency
- 12.1 Respiratory substrates and RQ
- 12.2 Aerobic respiration: the four stages
- 12.2 Anaerobic respiration
- 12.2 Rice and waterlogged roots
- 12.2 Investigating the rate of respiration
- 12.2 Exam tips
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13
Photosynthesis
Watch lesson- 13.1 The chloroplast
- 13.1 The two stages of photosynthesis
- 13.1 Chloroplast pigments
- 13.1 The light-dependent stage
- 13.1 The Calvin cycle
- 13.2 Limiting factors
- 13.2 Exam tips
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14
Homeostasis
Watch lesson- 14.1 What homeostasis is
- 14.1 The liver and urea
- 14.1 The kidney
- 14.1 Osmoregulation
- 14.1 Controlling blood glucose by cell signalling
- 14.2 Homeostasis in plants: the stomata
- 14.2 Exam tips
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15
Control and coordination
Watch lesson- 15.1 Two systems for control
- 15.1 Neurones
- 15.1 Detecting a stimulus
- 15.1 The nerve impulse
- 15.1 The synapse
- 15.1 Muscles and how they contract
- 15.2 Control and coordination in plants
- 15.2 Exam tips
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16
Inheritance
Watch lesson- 16.1 Meiosis and how it creates variation
- 16.1 The language of genetics
- 16.1 Genetic diagrams and crosses
- 16.1 The chi-squared test
- 16.2 From genes to proteins to phenotype
- 16.3 Gene control
- 16.3 Exam tips
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17
Selection and evolution
Watch lesson- 17.1 Variation
- 17.2 Natural selection
- 17.2 The Hardy–Weinberg principle
- 17.2 Selective breeding (artificial selection)
- 17.3 Evolution
- 17.3 Exam tips
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18
Classification, biodiversity and conservation
Watch lesson- 18.1 Classifying living things
- 18.2 Biodiversity
- 18.3 Conservation
- 18.3 Exam tips
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19
Genetic technology
Watch lesson- 19.1 Principles of genetic technology
- 19.2 Genetic technology in medicine
- 19.3 Genetically modified organisms in agriculture
- 19.3 Exam tips
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