The Cambridge AS and A Level Biology (9700) syllabus provides a detailed study of biological concepts, practical skills and their applications. The course covers topics ranging from cell structure, biological molecules, enzymes and genetics to respiration, photosynthesis, homeostasis, evolution and genetic technology.
This page follows the Cambridge International AS & A Level Biology 9700 syllabus for examinations in 2025, 2026 and 2027. AS Level students study Topics 1–11, while A Level students study the AS content together with Topics 12–19. The syllabus structure below includes the major topics and subtopics, with links to relevant Biology Notes Online study materials where available.
AS Level Biology
1. Cell Structure
1.1 The microscope in cell studies
- Preparation of temporary specimens for light microscopy
- Drawing cells from microscope slides and photomicrographs
- Calculating magnification and actual specimen size
- Using eyepiece graticules and stage micrometers
- Units: mm, µm and nm
- Magnification and resolution
- Light microscopy and electron microscopy
1.2 Cells as the basic units of living organisms
- Structure and function of eukaryotic cell components:
- Plant and animal cell structure
- ATP use in cellular processes
- Prokaryotic cell structure
- Comparison of prokaryotic and eukaryotic cells
- Virus structure
2. Biological Molecules
2.1 Testing for biological molecules
- Benedict’s test for reducing sugars
- Iodine test for starch
- Emulsion test for lipids
- Biuret test for proteins
- Semi-quantitative Benedict’s test
- Test for non-reducing sugars
- Acid hydrolysis
2.2 Carbohydrates and lipids
- α-glucose and β-glucose
- Monomers and polymers
- Macromolecules
- Monosaccharides, disaccharides and polysaccharides
- Reducing and non-reducing sugars
- Glycosidic bonds
- Condensation and hydrolysis
- Starch:
- Glycogen
- Cellulose
- Triglycerides
- Saturated and unsaturated fatty acids
- Glycerol
- Ester bonds
- Phospholipids
- Hydrophilic heads and hydrophobic tails
2.3 Proteins
- General structure of amino acids
- Peptide bond formation and breakage
- Primary protein structure
- Secondary protein structure
- Tertiary protein structure
- Quaternary protein structure
- Hydrophobic interactions
- Hydrogen bonds
- Ionic bonds
- Disulfide bonds
- Globular proteins
- Fibrous proteins
- Haemoglobin
- Collagen
2.4 Water
- Hydrogen bonding between water molecules
- Water as a solvent
- High specific heat capacity
- High latent heat of vaporisation
3. Enzymes
3.1 Mode of action of enzymes
- Intracellular and extracellular enzymes
- Active site
- Enzyme-substrate complex
- Activation energy
- Enzyme specificity
- Lock-and-key hypothesis
- Induced-fit hypothesis
- Measuring enzyme reaction rates
- Catalase investigations
- Amylase investigations
- Use of colorimeters
3.2 Factors that affect enzyme action
- Temperature
- pH
- Enzyme concentration
- Substrate concentration
- Inhibitor concentration
- Maximum reaction rate, \(V_{max}\)
- Michaelis–Menten constant, \(K_m\)
- Competitive inhibition
- Non-competitive inhibition
- Immobilised enzymes
- Alginate immobilisation
- Advantages of immobilised enzymes
4. Cell Membranes and Transport
4.1 Fluid mosaic membranes
- Fluid mosaic model
- Phospholipid bilayer
- Hydrophilic and hydrophobic interactions
- Membrane proteins
- Cholesterol
- Glycolipids
- Glycoproteins
- Membrane stability
- Membrane fluidity
- Membrane permeability
- Carrier proteins
- Channel proteins
- Cell-surface receptors
- Cell-surface antigens
- Cell signalling
- Ligands and target cells
4.2 Movement into and out of cells
- Simple diffusion
- Facilitated diffusion
- Osmosis
- Active transport
- Endocytosis
- Exocytosis
- Diffusion investigations
- Osmosis investigations
- Dialysis/Visking tubing
- Surface area-to-volume ratio
- Water potential
- Effects of water movement on plant cells
- Effects of water movement on animal cells
5. The Mitotic Cell Cycle
5.1 Replication and division of nuclei and cells
- Chromosome structure:
- DNA
- Histone proteins
- Sister chromatids
- Centromere
- Telomeres
- Importance of mitosis
- Growth
- Cell replacement
- Tissue repair
- Asexual reproduction
- Interphase
- G1 phase
- S phase
- G2 phase
- Mitosis
- Cytokinesis
- Role of telomeres
- Stem cells
- Uncontrolled cell division
- Tumour formation
5.2 Chromosome behaviour in mitosis
- Prophase
- Metaphase
- Anaphase
- Telophase
- Nuclear envelope changes
- Spindle behaviour
- Cell surface membrane changes
- Identification of mitotic stages from microscope images
6. Nucleic Acids and Protein Synthesis
6.1 Structure of nucleic acids and replication of DNA
- Nucleotide structure
- ATP as a phosphorylated nucleotide
- Purines:
- Pyrimidines:
- DNA double helix
- Antiparallel DNA strands
- Complementary base pairing
- Hydrogen bonding
- Phosphodiester bonds
- Semi-conservative DNA replication
- DNA polymerase
- DNA ligase
- Leading strand
- Lagging strand
- RNA structure
- mRNA
6.2 Protein synthesis
- Genes and polypeptides
- Universal genetic code
- Triplet code
- Start and stop codons
- Transcription
- Translation
- RNA polymerase
- mRNA
- Codons
- tRNA
- Anticodons
- Ribosomes
- Template DNA strand
- Non-template DNA strand
- Primary RNA transcript
- Introns
- Exons
- RNA processing
- Gene mutations
- Substitution
- Deletion
- Insertion
7. Transport in Plants
7.1 Structure of transport tissues
- Distribution of xylem and phloem
- Stem transverse sections
- Root transverse sections
- Leaf transverse sections
- Xylem vessel elements
- Phloem sieve tube elements
- Companion cells
- Structure-function relationships of transport tissues
7.2 Transport mechanisms
- Transport of mineral ions
- Transport of organic compounds
- Apoplast pathway
- Symplast pathway
- Endodermis
- Casparian strip
- Suberin
- Transpiration
- Cohesion-tension mechanism
- Transpiration pull
- Adhesion
- Xerophytic adaptations
- Sources and sinks
- Sucrose transport
- Amino acid transport
- Proton pumps
- Cotransporter proteins
- Mass flow in phloem
8. Transport in Mammals
8.1 The circulatory system
- Closed double circulation
- Heart
- Blood
- Arteries
- Arterioles
- Capillaries
- Venules
- Veins
- Pulmonary circulation
- Systemic circulation
- Pulmonary artery
- Pulmonary vein
- Aorta
- Vena cava
- Structure of arteries, veins and capillaries
- Red blood cells
- Monocytes
- Neutrophils
- Lymphocytes
- Tissue fluid
- Formation of tissue fluid
8.2 Transport of oxygen and carbon dioxide
- Haemoglobin
- Carbonic anhydrase
- Haemoglobinic acid
- Carbaminohaemoglobin
- Chloride shift
- Plasma transport of carbon dioxide
- Oxygen dissociation curve
- Partial pressure of oxygen
- Bohr shift
8.3 The heart
- External structure of the heart
- Internal structure of the heart
- Atria and ventricles
- Left and right ventricular wall thickness
- Cardiac cycle
- Systole
- Diastole
- Blood pressure changes
- Heart valves
- Sinoatrial node
- Atrioventricular node
- Purkyne tissue
9. Gas Exchange
9.1 The gas exchange system
- Lungs
- Trachea
- Bronchi
- Bronchioles
- Alveoli
- Capillary network
- Cartilage
- Ciliated epithelium
- Goblet cells
- Squamous epithelium
- Smooth muscle
- Mucous glands
- Elastic fibres
- Gas exchange between alveoli and blood
10. Infectious Diseases
10.1 Infectious diseases
- Pathogens and transmissible diseases
- Cholera
- Malaria
- Plasmodium falciparum
- Plasmodium malariae
- Plasmodium ovale
- Plasmodium vivax
- Tuberculosis
- Mycobacterium tuberculosis
- Mycobacterium bovis
- HIV/AIDS
- Disease transmission
- Disease prevention
- Disease control
- Biological factors
- Social factors
- Economic factors
10.2 Antibiotics
- Action of penicillin on bacteria
- Why antibiotics do not affect viruses
- Antibiotic resistance
- Reducing the impact of antibiotic resistance
11. Immunity
11.1 The immune system
- Macrophages
- Neutrophils
- Phagocytosis
- Antigens
- Self antigens
- Non-self antigens
- Primary immune response
- B-lymphocytes
- Plasma cells
- T-helper cells
- T-killer cells
- Memory cells
- Secondary immune response
- Long-term immunity
11.2 Antibodies and vaccination
- Antibody structure and function
- Hybridoma method
- Monoclonal antibodies
- Disease diagnosis using monoclonal antibodies
- Disease treatment using monoclonal antibodies
- Active immunity
- Passive immunity
- Natural immunity
- Artificial immunity
- Vaccines
- Vaccination programmes
A Level Biology
A Level students study the AS Level Topics 1–11 above plus Topics 12–19.
12. Energy and Respiration
12.1 Energy
- Energy requirements of living organisms
- Active transport
- Movement
- Anabolic reactions
- ATP as the universal energy currency
- ATP synthesis
- Substrate-linked phosphorylation
- Chemiosmosis
- Energy values of carbohydrates, lipids and proteins
- Respiratory quotient
- Calculating RQ
- Respirometers
12.2 Respiration
- Glycolysis
- Link reaction
- Krebs cycle
- Oxidative phosphorylation
- Cytoplasm and mitochondrial locations of respiratory stages
- Phosphorylation of glucose
- Fructose 1,6-bisphosphate
- Triose phosphate
- Pyruvate
- Reduced NAD
- Coenzyme A
- Acetyl coenzyme A
- Oxaloacetate
- Citrate
- Decarboxylation
- Dehydrogenation
- NAD
- FAD
- Electron transport chain
- Proton transfer
- ATP synthase
- Chemiosmosis
- Oxygen as the final electron acceptor
- Mitochondrial structure
- Lactate fermentation
- Ethanol fermentation
- Aerobic and anaerobic energy yields
- Rice adaptations to waterlogged conditions
- Redox indicators
- DCPIP
- Methylene blue
- Respiration investigations
13. Photosynthesis
13.1 Photosynthesis as an energy transfer process
- Chloroplast structure and function
- Light-dependent stage
- Light-independent stage
- Thylakoids
- Grana
- Stroma
- Chlorophyll a
- Chlorophyll b
- Carotene
- Xanthophyll
- Absorption spectra
- Action spectra
- Chromatography of photosynthetic pigments
- \(R_f\) values
- Cyclic photophosphorylation
- Non-cyclic photophosphorylation
- Photosystem I
- Photosystem II
- Photoactivation
- Photolysis
- Oxygen-evolving complex
- Electron transport chain
- Chemiosmosis
- ATP synthase
- Reduced NADP
- Calvin cycle
- Carbon fixation
- Rubisco
- RuBP
- GP
- TP
- Regeneration of RuBP
13.2 Investigation of limiting factors
- Light intensity
- Carbon dioxide concentration
- Temperature
- Limiting factors
- DCPIP investigations
- Methylene blue investigations
- Chloroplast suspension experiments
- Aquatic plant experiments
14. Homeostasis
14.1 Homeostasis in mammals
- Definition and importance of homeostasis
- Internal and external stimuli
- Receptors
- Nervous coordination
- Endocrine coordination
- Effectors
- Negative feedback
- Urea production
- Kidney structure
- Nephron structure
- Glomerulus
- Bowman’s capsule
- Proximal convoluted tubule
- Loop of Henle
- Distal convoluted tubule
- Collecting duct
- Ultrafiltration
- Selective reabsorption
- Osmoregulation
- Hypothalamus
- Posterior pituitary gland
- ADH
- Aquaporins
- Blood glucose regulation
- Insulin
- Glucagon
- Cell signalling
- G-proteins
- Adenylyl cyclase
- cAMP
- Protein kinase A
- Enzyme cascades
- Glucose test strips
- Biosensors
- Glucose oxidase
- Peroxidase
14.2 Homeostasis in plants
- Stomatal opening and closing
- Stomatal aperture
- Carbon dioxide uptake
- Water conservation
- Daily stomatal rhythms
- Guard cell structure and function
- Abscisic acid
- Water stress
- Calcium ions as second messengers
15. Control and Coordination
15.1 Control and coordination in mammals
- Endocrine system
- Nervous system
- Sensory neurones
- Motor neurones
- Intermediate neurones
- Sensory receptors
- Chemoreceptors
- Resting potential
- Action potential
- Refractory period
- Myelinated neurones
- Saltatory conduction
- Cholinergic synapses
- Calcium ions in synaptic transmission
- Neuromuscular junctions
- T-tubule system
- Sarcoplasmic reticulum
- Striated muscle
- Sarcomeres
- Sliding filament model
- Troponin
- Tropomyosin
- Calcium ions
- ATP
15.2 Control and coordination in plants
- Venus flytrap response
- Auxin
- Proton pumping
- Cell-wall acidification
- Elongation growth
- Gibberellin
- Barley germination
16. Inheritance
16.1 Passage of information from parents to offspring
- Haploid and diploid cells
- Homologous chromosomes
- Reduction division
- Meiosis
- Prophase I
- Metaphase I
- Anaphase I
- Telophase I
- Prophase II
- Metaphase II
- Anaphase II
- Telophase II
- Crossing over
- Independent assortment
- Random orientation
- Genetic variation
- Random fertilisation
16.2 The roles of genes in determining the phenotype
- Gene
- Locus
- Allele
- Dominant and recessive alleles
- Codominance
- Linkage
- Test crosses
- F1 and F2 generations
- Phenotype
- Genotype
- Homozygous
- Heterozygous
- Monohybrid crosses
- Dihybrid crosses
- Multiple alleles
- Sex linkage
- Autosomal linkage
- Epistasis
- Punnett squares
- Chi-squared test
- Genes, proteins and phenotype
- TYR gene and albinism
- HBB gene and sickle cell anaemia
- F8 gene and haemophilia
- HTT gene and Huntington’s disease
- Gibberellin and stem elongation
16.3 Gene control
- Structural genes
- Regulatory genes
- Repressible enzymes
- Inducible enzymes
- Lac operon
- Transcription factors
- Gene expression in eukaryotes
- Gibberellin
- DELLA proteins
17. Selection and Evolution
17.1 Variation
- Genetic variation
- Environmental variation
- Genetic-environmental interaction
- Discontinuous variation
- Continuous variation
- Genetic basis of variation
- t-test
17.2 Natural and artificial selection
- Natural selection
- Competition
- Survival and reproduction
- Stabilising selection
- Disruptive selection
- Directional selection
- Founder effect
- Genetic drift
- Bottleneck effect
- Antibiotic resistance
- Allele frequencies
- Hardy–Weinberg principle
- Artificial selection
- Selective breeding
- Disease resistance in wheat and rice
- Maize breeding
- Dairy cattle breeding
17.3 Evolution
- Evolution
- Gene pools
- Formation of new species
- DNA sequence evidence
- Evolutionary relationships
- Speciation
- Genetic isolation
- Allopatric speciation
- Sympatric speciation
18. Classification, Biodiversity and Conservation
18.1 Classification
- Biological species concept
- Morphological species concept
- Ecological species concept
- Three-domain system:
- Prokaryotic differences between Archaea and Bacteria
- Taxonomic hierarchy:
- Protoctista
- Fungi
- Plantae
- Animalia
- Virus classification
- DNA and RNA viruses
- Single-stranded and double-stranded viral genomes
18.2 Biodiversity
- Ecosystem
- Niche
- Ecosystem diversity
- Habitat diversity
- Species diversity
- Relative abundance
- Genetic diversity
- Random sampling
- Frame quadrats
- Line transects
- Belt transects
- Mark-release-recapture
- Lincoln index
- Spearman’s rank correlation
- Pearson’s linear correlation
- Biotic factors
- Abiotic factors
- Simpson’s index of diversity
18.3 Conservation
- Extinction
- Climate change
- Competition
- Hunting
- Habitat degradation
- Habitat loss
- Importance of biodiversity
- Zoos
- Botanic gardens
- National parks
- Marine parks
- Frozen zoos
- Seed banks
- IVF
- Embryo transfer
- Surrogacy
- Invasive alien species
- IUCN
- CITES
19. Genetic Technology
19.1 Principles of genetic technology
- Recombinant DNA
- Genetic engineering
- Gene transfer
- Extraction of genes from donor DNA
- Production of genes from mRNA
- Chemical synthesis of genes
- Restriction endonucleases
- DNA ligase
- Plasmids
- DNA polymerase
- Reverse transcriptase
- Promoters
- Marker genes
- Fluorescent products
- Gene editing
- DNA insertion
- DNA deletion
- DNA replacement
- Polymerase chain reaction
- Taq polymerase
- DNA amplification
- Gel electrophoresis
- Microarrays
- Genome analysis
- Gene-expression analysis
- Sequence databases
- Protein databases
19.2 Genetic technology applied to medicine
- Recombinant human proteins
- Recombinant insulin
- Factor VIII
- Adenosine deaminase
- Genetic screening
- BRCA1
- BRCA2
- Huntington’s disease
- Cystic fibrosis
- Gene therapy
- SCID
- Inherited eye diseases
- Social considerations
- Ethical considerations
19.3 Genetically modified organisms in agriculture
- Genetic engineering in food production
- Improving food quality
- Improving agricultural productivity
- GM salmon
- Herbicide-resistant soybean
- Insect-resistant cotton
- Ethical implications of GMOs
- Social implications of GMOs
Disclaimer
Disclaimer: The Cambridge International AS & A Level Biology Syllabus information provided on this page is intended for educational and reference purposes only. Biology Notes Online is an independent educational website and is not affiliated with, endorsed by, sponsored by or officially associated with Cambridge International Education. The syllabus has been independently organised to help students locate and understand the required Biology 9700 topics. Students and teachers should consult the official Cambridge International syllabus for the latest curriculum, examination requirements, updates and administrative information. For copyright concerns or content-related enquiries, contact biologynotesonlinecontact@gmail.com.
External References
- Cambridge International AS & A Level Biology (9700) – Official Course Page
Cambridge International AS & A Level Biology (9700) - Cambridge International AS & A Level Biology 9700 Syllabus – 2025, 2026 and 2027 (PDF)
Official Biology 9700 Syllabus PDF - Cambridge International AS & A Level Biology (9700) – Past Papers, Examiner Reports and Specimen Papers
Official Biology 9700 Past Papers and Specimen Papers