🧬 Biology · EF / Q-Phase · NRW / IB
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School-Based Biology Curriculum

EF + Qualifikationsphase (Q1/Q2) · IB Diploma Programme (SL/HL) integrated with NRW Kernlehrplan Biologie GOSt 2022

Subject: Biology / Biologie
Level: EF (intro) + Q1/Q2 (advanced)
IB Documents: Biology Guide 2023, First Assessment May 2025
NRW Documents: KLP Biologie GOSt 2022, KLP G9 Sek I 2019
Language: English (IB) / German (NRW-specific)
Hrs/week: EF 3 · SL/GK 3 · HL/LK 5
Version: May 2026

1. Preamble & Guiding Principles

This curriculum integrates two frameworks: the IB Biology Guide 2023 (First Assessment May 2025) — organised around four conceptual themes (A Unity & Diversity, B Form & Function, C Interaction & Interdependence, D Continuity & Change) across four levels (Molecules, Cells, Organisms, Ecosystems) — and the NRW Kernlehrplan Biologie GOSt 2022, structured as four Q-Phase Inhaltsfelder (Neurobiologie, Stoffwechselphysiologie, Ökologie, Genetik & Evolution) plus one EF Inhaltsfeld (Zellbiologie). Students following this curriculum are prepared to sit both the IB external examinations and the NRW Zentralabitur.

Four guiding principles:

  1. Prior knowledge made visible. Every content item is tagged to show whether it is known from Sec I, EF, the NRW Q-Phase, or genuinely new (IB-NEW).
  2. Dual accountability. Modules are sequenced so that NRW Pflichtinhalte run parallel to IB subtopics. NRW-only requirements (Bewertungskompetenz, specific contexts, Humanevolution) are clearly flagged.
  3. Research culture from day one. The IA research question is established early in Q1; the Collaborative Sciences Project (CSP) bridges Biology, Chemistry and Physics.
  4. Bilingual progression. Science vocabulary is built in English (IB exam language); German terms are provided for NRW Klausur readiness.

2. Colour & Tag System

Every content item in this document carries one status tag and, where applicable, one level tag:

Sec I Known from NRW G9 (classes 5–10) — brief activation only EF Covered in Einführungsphase — review in IB context NRW-Q NRW Q-Phase Kernlehrplan — parallel build IB-NEW Beyond NRW — must be taught as new content (SL) IB-NEW (HL) AHL extension — Higher Level only

ATL Skills (Approaches to Learning)

🧠 Thinking 💬 Communication ⚙️ Self-management 🔍 Research

IB Learner Profile (10 Attributes)

🔎 Inquirer📚 Knowledgeable 💡 Thinker🗣️ Communicator ⚖️ Principled🌍 Open-minded ❤️ Caring🚀 Risk-taker ⚖️ Balanced🪞 Reflective
🌍 INTERNATIONAL MINDEDNESS — global contexts embedded in every module
🤖 ACADEMIC INTEGRITY & AI — school-wide policy applies

3. Timetable & Module Overview

3.1 Total Teaching Hours

CourseHrs/weekSemestersTotal UStd.IB PracticalIACSP
SL / Grundkurs (incl. EF)36~27040 h10 h10 h
HL / Leistungskurs (incl. EF)5 (Q), 3 (EF)6~38060 h10 h10 h

3.2 Module Sequence

PhaseModuleTitleSL hrsHL hrsIB ThemesNRW IF
EFM1The Cell as a System1622A2.2, B2.2, A2.1(HL)Zellbiologie
M2Biomolecules & Membranes1418A1.1, B1.1, B1.2, B2.1, A1.2Zellbiologie
M3Cellular Metabolism & Enzymes1216C1.1, D2.3, B2.3 (part)Zellbiologie
M4Cell Division & Stem Cells1014D2.1, B2.3, D3.2 (intro)Zellbiologie
Q1M5Photosynthesis1420C1.3, B4.1Stoffwechselphysiologie
M6Cellular Respiration1218C1.2, B3.1, B3.2, B3.3(HL)Stoffwechselphysiologie
M7Molecular Genetics1826D1.1, D1.2, D1.3, D2.2(HL)Genetik & Evolution
M8Evolution, Speciation & Biodiversity1420D4.1, A4.1, A3.1, A3.2(HL), A4.2Genetik & Evolution
Q2M9Neural & Chemical Signalling1624C2.2, C2.1(HL), C3.1Neurobiologie
M10Homeostasis, Defence & Reproduction1420D3.3, C3.2, D3.1Neurobiologie + Genetik
M11Ecology & Climate Change1622C4.1, C4.2, B4.2, D4.2, D4.3Ökologie
M12Human Evolution & Behaviour (LK) / Cancer & Gene Technology818A4.1 ext., D1.3 ext.Genetik & Evolution (LK)

4. Competency Frameworks: IB & NRW Compared

NRW KompetenzbereichIB Assessment ObjectivePrimary Focus
UF – Umgang mit Fachwissen (UF1–UF4)AO1 Demonstrate knowledgeFacts, terminology, models
E – Erkenntnisgewinnung (E1–E17)AO2 Apply / AO3 Analyse & evaluateHypotheses, experiments, data, models
K – Kommunikation (K1–K14)Across all AOsScientific writing, presentation, bilingual
B – Bewertung (B1–B12)AO3 (ethical dimension) / IA EvaluationEthical, ecological, economic judgement
(implicit)AO4 Apply skills — ethical investigationMainly IA; Tools & Inquiry process

NRW Basiskonzepte: System · Struktur und Funktion · Entwicklung — mapped respectively to IB themes C (Interaction), B (Form & Function), D (Continuity & Change).

5. Teaching Modules

Click a module header to expand. ATL and Learner Profile tabs activate module-level filters.

M1 · EF
The Cell as a System
Sec I EF IB-NEW IB-NEW (HL)
🧠 Thinking 🔍 Research 💬 Communication
🔎 Inquirer 📚 Knowledgeable 💡 Thinker
SL 16 h · HL 22 h
IB Subtopics

Theme A A2.2 Cell structure (SL+HL) · Theme A A2.1 Origins of cells (HL) · Theme B B2.2 Organelles & compartmentalization (SL+HL)

NRW Connection

EF Inhaltsfeld Zellbiologie (UV Z1: Aufbau der Zelle — pro-/eukaryotisch, Kompartimentierung, Endosymbiontentheorie, Zelldifferenzierung). Basiskonzepte: System; Struktur und Funktion.

Learning Objectives
UF1 / AO1 · Students compare prokaryotic and eukaryotic cells and explain the evidence for the endosymbiont theory.
UF4 / AO2 · Students link organelle structure to function and predict effects of organelle malfunction.
E5 / AO3 (HL) · Students evaluate the RNA-world hypothesis as an explanation for the origin of life.
K1 / AO1 · Students draw and annotate cell diagrams using correct bilingual terminology.
Content (with tags)
  • Sec I Basic cell theory; prokaryote vs. eukaryote (size, nucleus, organelles)
  • EF Compartmentalization: membranes create distinct environments; mitochondria, chloroplasts, ER, Golgi, ribosomes, vacuoles
  • EF Endosymbiont theory: evidence (own DNA, double membrane, binary fission)
  • NRW-Q Cell differentiation: how one genome produces many cell types
  • IB-NEW Scale & microscopy: calculating magnification; electron vs. light microscopy
  • IB-NEW (HL) Origin of the first cells: RNA-world hypothesis, self-replicating molecules, protocells
  • IB-NEW (HL) A2.1: Pre-biotic chemistry, Miller-Urey experiment, significance for NoS
Experiments / Practical
  • Microscopy of prepared slides: onion epidermis, elodea, cheek cells — measure and calculate size
  • Preparation of temporary mounts: staining with iodine / methylene blue
  • Comparing electron micrographs of prokaryotes and eukaryotes (image analysis)
Sample Assessment Tasks
Task 1.A (SL · IB Paper 2 style)
AO1/AO2 · 5 marks
"A student observes a cell under the electron microscope. The cell has a diameter of 2 μm, no nuclear envelope, and ribosomes of 70S. Identify the cell type and outline two further structural features you would expect to find."
Task 1.B (NRW-Stil / Bewertung)
UF1/UF4, B2 · AFB II+III
„Erläutere die Endosymbiontentheorie und bewerte, inwiefern die vorliegenden Befunde (eigene DNA, Doppelmembran, Ribosomen 70S) diese Theorie stützen. Diskutiere mögliche Einschränkungen der Theorie."
Task 1.C (HL · IB Paper 2 extended)
AO3 · 8 marks
"Evaluate the RNA-world hypothesis as an explanation for the origin of life on Earth, with reference to the evidence from laboratory experiments and properties of RNA molecules."
ATL Skills, Learner Profile & IB Dimensions
ATL Skills – Approaches to Learning
🧠 ThinkingComparing prokaryote/eukaryote models as an exercise in classification and evidence-based reasoning
🔍 ResearchUsing primary microscopy data and published electron micrographs; evaluating source reliability
💬 CommunicationDrawing annotated cell diagrams in English; learning to use scientific vocabulary bilingually
IB Learner Profile
🔎 InquirerWhy did scientific models of the cell change over time? Tracing the development of the endosymbiont theory
📚 KnowledgeableCell structure as the foundational knowledge base for all subsequent modules
💡 ThinkerLinking abstract concepts (RNA world) to observable structural evidence — HL critical thinking
🌍 INTERNATIONAL MINDEDNESS
The endosymbiont theory was developed by Lynn Margulis (USA, 1967) after initial rejection by mainstream science — a case study in scientific dissent and eventual acceptance. Cell biology is a truly global enterprise: the Nobel Prize for the ribosome structure (2009) went to researchers from USA, UK and Israel working with crystallography developed internationally. Discuss: does science have a nationality?
🤖 ACADEMIC INTEGRITY & AI
AI tools can generate and label cell diagrams and explain organelle functions — useful for self-study. Drawing annotated diagrams by hand remains a core IB examination skill. For Klausuren and the Abitur, the school-wide Academic Integrity Policy applies. AI use must be declared where permitted.
M2 · EF
Biomolecules & Membranes
Sec I EF IB-NEW
🧠 Thinking 🔍 Research 💬 Communication
📚 Knowledgeable 💡 Thinker 🔎 Inquirer
SL 14 h · HL 18 h
IB Subtopics

Theme A A1.1 Water · A1.2 Nucleic acids · Theme B B1.1 Carbohydrates & lipids · B1.2 Proteins · B2.1 Membranes & membrane transport

NRW Connection

EF Inhaltsfeld Zellbiologie (UV Z2: Biomembranen — Stoffgruppen, Transport, Signaltransduktion, Zell-Zell-Erkennung). Basiskonzepte: Struktur und Funktion; System.

Learning Objectives
UF1/AO1 · Students describe the structure and biological roles of water, carbohydrates, lipids, proteins and nucleic acids.
UF4/AO2 · Students explain how the fluid-mosaic model accounts for membrane properties and transport mechanisms.
E5/AO2 · Students predict and explain the results of osmosis and diffusion experiments quantitatively.
K1 · Students use correct IUPAC and biological nomenclature bilingually in lab reports.
Content (with tags)
  • Sec I Water as solvent; importance for life; H-bonds qualitatively
  • EF Carbohydrates: monosaccharides, disaccharides, polysaccharides; condensation & hydrolysis
  • EF Lipids: triglycerides, phospholipids, sterols; saturated vs. unsaturated
  • EF Proteins: amino acids, peptide bonds, primary to quaternary structure, denaturation
  • EF Fluid-mosaic model: phospholipid bilayer, integral/peripheral proteins, cholesterol
  • EF Membrane transport: diffusion, facilitated diffusion, osmosis, active transport, endo-/exocytosis
  • NRW-Q Signal transduction at membrane: receptor proteins, ligands, cell-cell recognition (glycoproteins)
  • IB-NEW A1.1: Water's cohesion, adhesion, thermal properties, and role as a medium for biochemistry (quantitative)
  • IB-NEW A1.2: DNA vs. RNA structure; nucleotide components; antiparallel strands; base pairing rules
  • IB-NEW Chromatography (Rf values) as a Tool for lipid/pigment separation
Experiments / Practical
  • Osmosis in plant tissue (potato cylinders): graph mass change vs. sucrose concentration; determine water potential
  • Thin-layer chromatography of leaf pigments; calculate Rf values
  • Biuret and Benedict's tests: qualitative and semi-quantitative protein/sugar detection
  • Dialysis tubing membrane permeability investigation (IA-preparatory: variable control)
Sample Assessment Tasks
Task 2.A (SL · IB Paper 1B data-based)
AO2/AO3 · 6 marks
"[Graph: mass change of potato cylinders in sucrose solutions 0–1.0 mol dm⁻³]. Determine the solute concentration of the potato tissue from the graph. Explain the change in mass at concentrations above the isotonic point. Suggest one source of systematic error."
Task 2.B (NRW-Stil)
UF4, E4 · AFB II
„Erläutere das Fluid-Mosaik-Modell der Biomembran und erkläre, warum die Membranfluidität bei Organismen aus verschiedenen Klimazonen (z. B. Arktis vs. Tropen) unterschiedlich ist. Begründe mithilfe des Aufbaus der Membranlipide."
ATL Skills, Learner Profile & IB Dimensions
ATL Skills
🧠 ThinkingStructure-function reasoning: why does a phospholipid bilayer self-assemble? — emergent properties from molecular structure
🔍 ResearchDesigning controlled osmosis experiments; identifying variables; interpreting graphical data
💬 CommunicationDrawing the fluid-mosaic model from memory; writing formal lab reports with correct units and error analysis
IB Learner Profile
📚 KnowledgeableBiochemical structures are the foundation for understanding physiology, pharmacology and biotechnology
💡 ThinkerMembrane adaptations across climates: one molecule, many contexts — systems thinking
🔎 InquirerOsmosis experiment as IA preparation: generating a research question and testing it quantitatively
🌍 INTERNATIONAL MINDEDNESS
The structure of DNA was determined in 1953 by Watson, Crick, Franklin and Wilkins — an international team at Cambridge. Rosalind Franklin's X-ray crystallography data (UK) was central; the Nobel Prize (1962) did not include Franklin (who had died). This raises questions about attribution, gender and recognition in global science. Cholesterol-lowering statins: developed from Japanese fungi (Endo, 1976); now one of the world's most prescribed drugs — global health impact of a single biochemical insight.
🤖 ACADEMIC INTEGRITY & AI
AI can generate structural diagrams of biomolecules and explain membrane transport — excellent for self-study and checking understanding. For IA data analysis, AI assistance in graph interpretation must be declared. Drawing membrane models and molecular structures by hand is an IB examination skill that cannot be delegated.
M3 · EF
Cellular Metabolism & Enzymes
EFNRW-QIB-NEW
🧠 Thinking🔍 Research⚙️ Self-mgmt
🔎 Inquirer💡 Thinker
SL 12 h · HL 16 h
IB Subtopics

Theme C C1.1 Enzymes and metabolism · Theme D D2.3 Water potential

NRW Connection

EF UV Z4: ATP/ADP, Redox, Anabolismus/Katabolismus, Enzymkinetik & -regulation, Homöostase/Osmoregulation.

Content (with tags)
  • EF ATP as energy currency; ATP ↔ ADP + Pi; anabolism vs. catabolism
  • EF Enzyme structure; active site; lock-and-key and induced-fit models
  • EF Factors affecting enzyme activity: T, pH, substrate concentration; inhibition
  • NRW-Q Allosteric regulation; feedback inhibition; competitive vs. non-competitive inhibition
  • IB-NEW Michaelis-Menten kinetics (HL): V_max, K_m, substrate affinity (HL)
  • IB-NEW D2.3 Water potential (Ψ = Ψ_s + Ψ_p): quantitative concept; predicting direction of water movement
  • IB-NEW Redox reactions in metabolism: NAD⁺/NADH, FAD/FADH₂ as electron carriers
Experiments / Practical
  • Catalase activity (H₂O₂ breakdown): effect of temperature, pH, substrate concentration — graph and interpret Vmax
  • Immobilised enzyme investigation (alginate beads): compare free vs. immobilised lactase
  • Water potential of potato: plasmolysis observation; calculate Ψ_s from sucrose molarity at incipient plasmolysis
ATL, LP & IB Dimensions
ATL Skills
🧠 ThinkingInterpreting enzyme kinetics graphs; predicting effects of inhibitors on Vmax and Km
🔍 ResearchDesigning controlled enzyme experiments for IA preparation; variable identification
⚙️ Self-mgmtManaging time in multi-step practical; recording raw data accurately and immediately
IB Learner Profile
🔎 InquirerDesigning an enzyme experiment: generating a testable hypothesis and choosing appropriate variables
💡 ThinkerWater potential: a quantitative model that unifies osmosis across contexts (plant physiology, kidney, IV drips)
🌍 INTERNATIONAL MINDEDNESS
Enzymes in industry: detergent enzymes (proteases, lipases, amylases) are produced globally by fermentation — a multi-billion-euro market largely developed in Denmark (Novozymes). Drug design uses enzyme inhibitors: HIV protease inhibitors were developed through international collaborations in the 1990s and transformed HIV into a manageable condition. Access to these drugs remains unequal globally.
🤖 ACADEMIC INTEGRITY & AI
AI can explain enzyme kinetics and generate practice data sets — valuable for self-study. For enzyme IA: the experimental design, raw data and conclusions must be entirely the student's own work. Citing AI as a source of background information is acceptable with declaration.
M4 · EF
Cell Division & Stem Cells
EFNRW-QIB-NEW
🧠 Thinking💬 Communication
⚖️ Principled💡 Thinker⚖️ Balanced
SL 10 h · HL 14 h
IB Subtopics

Theme D D2.1 Cell and nuclear division · Theme B B2.3 Cell specialization · Theme D D3.2 Inheritance (intro to meiosis)

NRW Connection

EF UV Z3: Chromosomen, Mitose, Meiose, Zellzyklus-Regulation, Genommutationen, Stammzellen-Bewertung (Bewertungskompetenz B2). Basiskonzept: Entwicklung.

Content (with tags)
  • EF Mitosis: prophase, metaphase, anaphase, telophase; sister chromatids; cytokinesis
  • EF Cell cycle: interphase (G1, S, G2), cyclin-CDK regulation (qualitative)
  • EF Meiosis I & II; crossing over; independent assortment → genetic variation
  • NRW-Q Chromosome mutations: non-disjunction, trisomy 21; karyotypes
  • NRW-Q Stem cells: totipotent, pluripotent, multipotent; embryonic vs. adult vs. iPS cells
  • NRW-Q Bewertung (B2): ethical perspectives on embryonic stem cell research — Bewertungskompetenz
  • IB-NEW B2.3: mechanisms of differentiation; role of transcription factors; epigenetic silencing
  • IB-NEW Therapeutic cloning and regenerative medicine: current state of research
Experiments / Practical
  • Mitosis in onion root tip: prepare squash, stain with orcein; calculate mitotic index
  • Modelling meiosis with pop-it bead chromosomes: simulate crossing over and independent assortment
  • Case study debate: embryonic stem cells vs. adult stem cells vs. iPS cells (structured academic controversy)
ATL, LP & IB Dimensions
ATL Skills
🧠 ThinkingCalculating mitotic index from microscopy data; predicting effects of cell cycle disruption (cancer connection)
💬 CommunicationPresenting the stem cell ethics debate as a structured academic controversy with evidence-based arguments
Collaborative modelling of meiosis; group debate on stem cell ethics respecting diverse perspectives
IB Learner Profile
⚖️ PrincipledStem cell research raises questions about when life begins — students engage with competing ethical frameworks
💡 ThinkerHow does one genome produce 200+ cell types? The logic of differential gene expression
⚖️ BalancedBalancing medical promise of stem cell therapy against ethical concerns — NRW Bewertungskompetenz B2
🌍 INTERNATIONAL MINDEDNESS
Stem cell research regulations differ dramatically worldwide: Germany prohibits import of embryonic stem cell lines created after 2002 (Stammzellgesetz); the UK, USA and Japan have more permissive frameworks; South Korea's Hwang Woo-suk scandal (2005) showed how global scientific competition can lead to fraud. iPS cells (Yamanaka, Japan — Nobel 2012) are now seen as an ethical alternative. Discuss how national laws shape the direction of global science.
🤖 ACADEMIC INTEGRITY & AI
AI can generate summaries of the stem cell ethics debate — useful background. For the structured academic controversy task, students must develop their own argumentation. Mitotic index calculations must be based on the student's own microscope images or provided data.
M5 · Q1
Photosynthesis
NRW-QIB-NEWIB-NEW (HL)
🧠 Thinking🔍 Research💬 Communication
🔎 Inquirer💡 Thinker⚖️ Balanced
SL 14 h · HL 20 h
IB Subtopics

Theme C C1.3 Photosynthesis (SL+HL) · Theme B B4.1 Adaptation to environment

NRW Connection

Q-Phase Inhaltsfeld Stoffwechselphysiologie: Blattaufbau, Chloroplast-Ultrastruktur, Absorptions-/Wirkungsspektrum, Lichtreaktion (Photosystem I/II), Calvin-Zyklus, Limitierungsfaktoren. LK: Lichtsammelkomplexe, C4-Pflanzen, energetisches Modell. Basiskonzept: Struktur und Funktion; Energie.

Content (with tags)
  • NRW-Q Chloroplast structure: thylakoid membranes, stroma, grana; pigments and absorption spectra
  • NRW-Q Light-dependent reactions: photolysis of water, electron transport, ATP synthesis, NADPH production
  • NRW-Q Calvin cycle: CO₂ fixation (RuBisCO), G3P production, RuBP regeneration
  • NRW-Q Limiting factors: light intensity, CO₂ concentration, temperature — graphs and interpretation
  • IB-NEW Chromatography of photosynthetic pigments: Rf values (Tool 1)
  • IB-NEW Chemiosmosis in thylakoids: proton gradient, ATP synthase, quantitative link to electron transport
  • IB-NEW (HL) Light-harvesting complexes: structure and function of antenna pigments
  • IB-NEW (HL) C4 photosynthesis: bundle sheath cells, spatial separation, advantage in hot climates
  • IB-NEW (HL) Cyclic vs. non-cyclic electron flow; photorespiration and its ecological significance
Experiments / Practical
  • Chromatography of leaf pigments: Rf calculation; identify chlorophylls a, b, carotene, xanthophyll
  • Measuring photosynthesis rate: oxygen evolution with pond weed (Elodea) — effect of light intensity and wavelength
  • Leaf disc assay (floating discs): infiltration with bicarbonate solution, counting discs that float as proxy for O₂ production
Sample Assessment Tasks
Task 5.A (SL · IB Paper 2)
AO2/AO3 · 7 marks
"[Graph: rate of photosynthesis vs. light intensity at two CO₂ concentrations]. Identify the limiting factor at point X. Explain why the curves plateau at different rates. Deduce what would happen to the Calvin cycle if the light reactions were suddenly stopped."
Task 5.B (NRW-Stil)
UF3, E5 · AFB II+III
„Erläutere die Lichtreaktionen der Fotosynthese und erkläre, wie die chemiosmotische ATP-Synthese in der Thylakoidmembran funktioniert. Beurteile, welche ökologische Bedeutung C4-Pflanzen (LK) in Zeiten des Klimawandels haben könnten."
ATL, LP & IB Dimensions
ATL Skills
🧠 ThinkingTracing energy flow from photons to ATP to carbon fixation — systemic thinking across multiple scales
🔍 ResearchDesigning leaf disc assays with appropriate controls; analysing limiting factor graphs
💬 CommunicationAnnotating thylakoid/stroma diagrams with electron flow and ATP synthesis
IB Learner Profile
🔎 InquirerDesigning an IA on photosynthesis: which variable (wavelength, CO₂, temperature) produces the most interesting data?
💡 ThinkerChemiosmosis: the same mechanism drives ATP synthesis in chloroplasts AND mitochondria — convergent evolution or common ancestry?
⚖️ BalancedC4 plants and climate change: potential for engineered C4 rice — balancing food security against ecological risk
🌍 INTERNATIONAL MINDEDNESS
The Calvin cycle was elucidated by Melvin Calvin (USA, Nobel 1961) using radioactive ¹⁴C — a postwar application of nuclear technology to understand life. Global food security depends on photosynthetic efficiency: the International Rice Research Institute (IRRI, Philippines) is engineering C4 rice. Deforestation in the Amazon reduces global photosynthesis capacity — a planetary-scale consequence of local decisions. Who makes decisions about global carbon fixation?
🤖 ACADEMIC INTEGRITY & AI
AI can simulate limiting factor graphs and explain chemiosmosis clearly — excellent learning tool. For photosynthesis IA: raw data must be collected by the student; AI may assist in graph formatting and statistical analysis only if declared. The Research Design and Conclusion sections must be written independently.
M6 · Q1
Cellular Respiration
NRW-QIB-NEWIB-NEW (HL)
🧠 Thinking🔍 Research⚙️ Self-mgmt
💡 Thinker🔎 Inquirer📚 Knowledgeable
SL 12 h · HL 18 h
IB Subtopics

Theme C C1.2 Cell respiration (SL+HL) · Theme B B3.1 Gas exchange · B3.2 Transport · B3.3 Muscle and motility (HL only)

NRW Connection

Q-Phase Stoffwechselphysiologie: Mitochondrium-Ultrastruktur, Glykolyse, oxidative Decarboxylierung, Citratzyklus, Atmungskette, chemiosmotische ATP-Bildung. LK: Gärungen, energetisches Modell, Tracer-Methode. Gas exchange and transport in Sek I (Blutkreislauf, Lunge).

Content (with tags)
  • NRW-Q Mitochondria: cristae, matrix, inter-membrane space — structure & function
  • NRW-Q Glycolysis (cytosol): glucose → 2 pyruvate; net gain 2 ATP, 2 NADH
  • NRW-Q Pyruvate oxidation: acetyl-CoA formation; CO₂ release
  • NRW-Q Krebs/TCA cycle: per-turn yield; CO₂, NADH, FADH₂, ATP
  • NRW-Q Electron transport chain: NADH/FADH₂ donate electrons; O₂ as final acceptor; chemiosmosis (ATP synthase)
  • IB-NEW Anaerobic respiration: lactate fermentation (animals), ethanol fermentation (yeast); RQ values
  • IB-NEW B3.1 Gas exchange: counter-current exchange in fish gills; alveolar surface adaptations
  • IB-NEW B3.2 Transport: haemoglobin oxygen dissociation curves; Bohr effect; blood vs. xylem vs. phloem
  • IB-NEW (HL) Electron carriers: ubiquinone, cytochrome c; detailed proton pumping complexes I, III, IV
  • IB-NEW (HL) B3.3 Muscle and motility: sliding-filament theory; myosin ATPase; neuromuscular junction; slow vs. fast fibres
Experiments / Practical
  • Respirometer: measure O₂ consumption of germinating seeds at different temperatures (IA-preparatory)
  • Yeast fermentation: CO₂ production rate vs. temperature or sugar type — graph and interpret
  • Dissection of fish gill or pig heart (or model/virtual): identify gas exchange or transport structures
ATL, LP & IB Dimensions
ATL Skills
🧠 ThinkingTracing carbon atoms from glucose through glycolysis, TCA cycle to CO₂ — systems-level metabolic mapping
🔍 ResearchRespirometer design: controlling variables; calculating O₂ consumption rates with appropriate units
⚙️ Self-mgmtManaging multi-step practical; recording data in real time; calculating ATP yield from electron carriers
IB Learner Profile
💡 ThinkerChemiosmosis links photosynthesis and respiration — the same ATP synthase in two different organelles
🔎 InquirerYeast fermentation: which sugar is metabolised most efficiently? Designing a fair test
📚 KnowledgeableATP yield per glucose — connecting molecular detail to whole-organism physiology (exercise, altitude)
🌍 INTERNATIONAL MINDEDNESS
Altitude physiology: athletes from high-altitude countries (Ethiopia, Kenya) have physiological adaptations in haemoglobin affinity and red blood cell count. Blood doping in sport exploits haemoglobin biology — WADA (international) monitors this globally. Muscle fibre-type differences explain performance variation across populations: sprint events vs. endurance — ethical dimensions of genetic selection in sport.
🤖 ACADEMIC INTEGRITY & AI
AI can generate metabolic pathway diagrams and practice calculation problems — useful for self-testing. Respirometer IA: all experimental measurements must be collected by the student. AI-generated data is never acceptable as raw data. Statistical analysis (mean, SD, t-test) may use AI tools with full declaration.
M7 · Q1
Molecular Genetics
NRW-QIB-NEWIB-NEW (HL)
🧠 Thinking🔍 Research💬 Communication
🔎 Inquirer⚖️ Principled📚 Knowledgeable
SL 18 h · HL 26 h
IB Subtopics

Theme D D1.1 DNA replication · D1.2 Protein synthesis · D1.3 Mutation and gene editing · D2.2 Gene expression (HL)

NRW Connection

Q-Phase Genetik & Evolution: DNA-Struktur, semikonservative Replikation, Transkription, Translation, Genregulation Eukaryoten (Transkriptionsfaktoren, DNA-Methylierung). LK: Histonmodifikation, RNA-Interferenz, Krebs-Onkogene, PCR, Gelelektrophorese, Gentechnik, Gentherapie.

Content (with tags)
  • NRW-Q DNA replication: semi-conservative; leading/lagging strand; DNA helicase, primase, DNA polymerase δ/ε, ligase
  • NRW-Q Transcription: RNA polymerase; promoter, terminator; pre-mRNA; splicing (exons/introns)
  • NRW-Q Translation: ribosomes; codons/anticodons; initiation, elongation, termination; polyribosomes
  • NRW-Q Gene regulation: transcription factors; enhancers; DNA methylation (epigenetics)
  • NRW-Q Mutation types: substitution, insertion, deletion; frameshift; consequences for protein
  • NRW-Q Biotechnology: PCR; gel electrophoresis; restriction enzymes; recombinant DNA; gene therapy ethics
  • IB-NEW D1.3: CRISPR-Cas9 — mechanism of guide RNA, Cas9 cutting, HDR vs. NHEJ repair
  • IB-NEW Applications of CRISPR: sickle cell disease, agriculture, de-extinction — with ethical debate
  • IB-NEW (HL) D2.2 Gene expression regulation: histone modifications (acetylation, methylation); RNA interference (siRNA, miRNA)
  • IB-NEW (HL) Oncogenes and tumour suppressor genes: how mutations in cell cycle regulators cause cancer
Experiments / Practical
  • Gel electrophoresis simulation: DNA fingerprinting from restriction enzyme digestion — interpret banding patterns
  • PCR concept modelling: thermal cycler cycles; primer design; why specific temperatures matter
  • Bioinformatics: BLAST search comparing homologous gene sequences across species (computer practical)
ATL, LP & IB Dimensions
ATL Skills
🧠 ThinkingTracing information flow from DNA → mRNA → protein; predicting effects of frameshift mutations
🔍 ResearchBioinformatics: using BLAST to compare sequences; evaluating gene therapy clinical trial data
💬 CommunicationPresenting the CRISPR ethics debate; writing a structured scientific argument about germline editing
IB Learner Profile
🔎 InquirerHow does CRISPR know where to cut? Investigating the guide RNA mechanism through primary literature
⚖️ PrincipledGermline CRISPR editing (He Jiankui case, 2018): where are the ethical limits of gene editing?
📚 KnowledgeableDNA replication fidelity: error rates and DNA repair mechanisms — linking molecular detail to cancer biology
🌍 INTERNATIONAL MINDEDNESS
CRISPR-Cas9 was developed by Doudna (USA) and Charpentier (France/Germany) — Nobel Prize 2020. He Jiankui's experiment (China, 2018) — creating the first gene-edited human babies — provoked a global ethical crisis and highlighted the need for international governance of gene editing. The Sickle Cell Disease CRISPR trial (USA/UK) was approved in 2023: who has access? LGMD gene therapy: cost ~$3.5 million per patient. Global inequity in access to genetic medicine.
🤖 ACADEMIC INTEGRITY & AI
AI can explain CRISPR mechanism clearly and generate practice questions on protein synthesis. For any essay or report on CRISPR ethics: AI-generated arguments must be declared and the student must demonstrate their own reasoning in the Abschlussgespräch (if this is a Facharbeit). Bioinformatics practicals using public databases (BLAST, Ensembl) are legitimate research tools.
M8 · Q1
Evolution, Speciation & Biodiversity
NRW-QIB-NEWIB-NEW (HL)
🧠 Thinking🔍 Research💬 Communication
🌍 Open-minded❤️ Caring💡 Thinker
SL 14 h · HL 20 h
IB Subtopics

Theme D D4.1 Natural selection · Theme A A4.1 Evolution and speciation · A3.1 Diversity of organisms · A3.2 Classification and cladistics (HL) · A4.2 Conservation of biodiversity

NRW Connection

Q-Phase Genetik & Evolution: synthetische Evolutionstheorie, Mutation/Rekombination/Selektion/Gendrift, adaptiver Wert, Artbegriff, Isolation, molekularbiologische Homologien, Koevolution. LK: Humanevolution, kulturelle Evolution, Sozialverhalten Primaten. Ökologie: Biodiversität.

Content (with tags)
  • NRW-Q Synthetic theory of evolution: mutation, recombination, selection, genetic drift, gene flow
  • NRW-Q Speciation: allopatric and sympatric; reproductive isolation mechanisms; biological species concept
  • NRW-Q Evidence for evolution: fossil record, comparative anatomy, molecular homology, biogeography
  • NRW-Q Hardy-Weinberg equilibrium: calculating allele frequencies; conditions for equilibrium
  • IB-NEW A3.1: Three-domain system (Bacteria, Archaea, Eukarya); binomial nomenclature; classification levels
  • IB-NEW A4.2: Biodiversity indices (Simpson's index D); threats to biodiversity; conservation strategies
  • IB-NEW Natural selection types: directional, stabilising, disruptive — with graphical examples
  • IB-NEW (HL) A3.2 Cladistics: shared derived characters; constructing cladograms from morphological and molecular data; molecular clock
  • IB-NEW (HL) A3.2: Three-domain rRNA evidence; paraphyletic and polyphyletic groups
Experiments / Practical
  • Hardy-Weinberg calculation: use population genetics data to test whether a population is in equilibrium
  • Constructing cladograms from morphological character matrices (HL)
  • Simpson's diversity index: calculating D from survey data; comparing two habitats
  • Case study: antibiotic resistance as evolution in real time (selection in bacterial populations)
ATL, LP & IB Dimensions
ATL Skills
🧠 ThinkingUsing Hardy-Weinberg as a null model — statistical reasoning in population genetics
🔍 ResearchConstructing and interpreting cladograms from molecular data (HL); evaluating extinction risk data
💬 CommunicationExplaining evolutionary concepts without teleological language; correcting common misconceptions
IB Learner Profile
🌍 Open-mindedEvolution challenges some cultural and religious worldviews — discussing with respect and scientific rigour
❤️ CaringBiodiversity loss is happening now — what is our responsibility? Conservation as an ethical obligation
💡 ThinkerCladistics: how molecular data overturned traditional morphological classification — science revising itself
🌍 INTERNATIONAL MINDEDNESS
Darwin's theory was developed through global travel (HMS Beagle) and relies on specimens collected worldwide — early biogeography as colonialism? The three-domain system was proposed by Carl Woese (USA, 1977) using rRNA sequences — previously unknown Archaea found in extreme environments globally. Biodiversity hotspots are disproportionately in the Global South (Brazil, Indonesia, Madagascar) — who bears the cost of conservation? Convention on Biological Diversity (CBD): global treaty, local impact.
🤖 ACADEMIC INTEGRITY & AI
AI can construct phylogenetic trees from input data and explain cladistic principles — useful for exploration. In assessments, students must construct cladograms independently. When researching biodiversity topics for essays or Facharbeiten, AI-generated statistics must be verified against primary sources (IUCN Red List, etc.).
M9 · Q2
Neural & Chemical Signalling
NRW-QIB-NEWIB-NEW (HL)
🧠 Thinking🔍 Research💬 Communication
📚 Knowledgeable💡 Thinker🪞 Reflective
SL 16 h · HL 24 h
IB Subtopics

Theme C C2.2 Neural signalling (SL+HL) · C2.1 Chemical signalling (HL) · C3.1 Integration of body systems (SL+HL)

NRW Connection

Q-Phase Neurobiologie: Bau & Funktion Neuron (Ruhepotenzial, Aktionspotenzial, Erregungsleitung), chemische erregende Synapse, neuromuskuläre Synapse, Stoffeinwirkung. LK: Sinneszellen (primär/sekundär), Hormone & Verschränkung, hemmende Synapsen, räumliche/zeitliche Summation, zelluläre Lernprozesse, neurophysiologische/bildgebende Verfahren, Störungen.

Content (with tags)
  • NRW-Q Neuron structure: dendrites, cell body, axon, myelin sheath, nodes of Ranvier
  • NRW-Q Resting potential: Na⁺/K⁺ pump; −70 mV; selective permeability
  • NRW-Q Action potential: depolarisation, repolarisation, refractory period; saltatory conduction
  • NRW-Q Excitatory chemical synapse: Ca²⁺ trigger, neurotransmitter release, receptor binding, EPSP
  • NRW-Q Effect of drugs: nicotine, caffeine, SSRI, opioids — mechanism at synapse level
  • NRW-Q (LK) Inhibitory synapses (IPSP); spatial and temporal summation; Hebb's rule (synaptic plasticity); LTP
  • NRW-Q (LK) Sensory receptors: primary vs. secondary; receptor potential; transduction
  • IB-NEW C3.1: Feedback control — negative feedback in insulin/glucagon regulation; thyroid hormone axis
  • IB-NEW (HL) C2.1 Chemical signalling: peptide vs. steroid hormones; receptor types (membrane vs. intracellular); second messenger cascades (cAMP, IP₃)
  • IB-NEW (HL) Signal transduction pathways: G-protein coupled receptors; amplification; cross-talk
Experiments / Practical
  • Reaction time investigation: ruler drop test; effect of distraction or fatigue — IA-preparatory design
  • Electrocardiogram (ECG) trace analysis: identifying P, QRS, T waves; calculate heart rate and rhythm
  • Case study: Parkinson's disease and dopamine signalling; pharmacological interventions
ATL, LP & IB Dimensions
ATL Skills
🧠 ThinkingModelling how inhibitory and excitatory inputs summate to reach threshold — quantitative neural integration
🔍 ResearchEvaluating primary literature on synaptic plasticity; using ECG data to diagnose arrhythmias
💬 CommunicationPresenting drug mechanisms at the synapse level; explaining feedback systems with diagrams
Reaction time group experiment: collaborative data collection and statistical analysis
IB Learner Profile
📚 KnowledgeableNeural signalling connects molecular events (ion channels) to whole-brain function — multi-scale understanding
💡 ThinkerWhy do opioids cause addiction? Tracing receptor desensitisation and neuroplasticity at the molecular level
🪞 ReflectiveNeuroethics: brain imaging can now reveal mental states — who owns brain data? Implications for privacy
🌍 INTERNATIONAL MINDEDNESS
The opioid crisis is largely a North American phenomenon driven by pharmaceutical marketing (OxyContin); other countries have different prescribing cultures. Global mental health burden: depression affects 280 million people worldwide; antidepressants (SSRIs) were developed in the USA/UK but access is highly unequal. Deep brain stimulation for Parkinson's: a North American/European technology not accessible in most of the world. Discuss: who benefits from neuroscience research?
🤖 ACADEMIC INTEGRITY & AI
AI can explain receptor mechanisms and generate action potential graphs — excellent for self-study. Reaction time IA: all experimental data must be collected by students. AI may assist in statistical analysis (t-test, error bars) with declaration. Neuroethics essays: AI-generated arguments must be declared; independent reasoning is assessed in the Abschlussgespräch.
M10 · Q2
Homeostasis, Defence & Reproduction
NRW-QIB-NEWIB-NEW (HL)
🧠 Thinking🔍 Research
⚖️ Principled❤️ Caring🌍 Open-minded
SL 14 h · HL 20 h
IB Subtopics

Theme D D3.3 Homeostasis · Theme C C3.2 Defence against disease · Theme D D3.1 Reproduction

NRW Connection

EF: Osmoregulation/Homöostase. LK Neurobiologie: Hormone & Verschränkung (Diabetes, Stresshormone). Sek I: Immunsystem ansatzweise. D3.1 (Reproduction) nicht systematisch im KLP GOSt. C3.2 Defence against disease: großer Ergänzungsbedarf — IB-NEU für NRW-Schüler:innen.

Content (with tags)
  • NRW-Q D3.3 Homeostasis: negative feedback loops; blood glucose regulation (insulin/glucagon); thermoregulation (ecto- vs. endotherms)
  • NRW-Q (LK) Diabetes type 1 vs. type 2: molecular basis; treatment strategies
  • IB-NEW C3.2 Innate immunity: physical barriers (skin, mucus), phagocytosis, inflammation, natural killer cells, fever
  • IB-NEW C3.2 Adaptive immunity: B cells → plasma cells → antibodies; T helper and T killer cells; immunological memory
  • IB-NEW Vaccination: attenuated, killed, subunit, mRNA vaccines; herd immunity; immunisation schedules
  • IB-NEW D3.1 Reproduction: oogenesis and spermatogenesis; menstrual cycle (FSH, LH, oestrogen, progesterone); IVF ethics
  • IB-NEW Sexually transmitted infections: HIV life cycle; reverse transcriptase; antiretroviral therapy
  • IB-NEW (HL) C3.2 Antibody structure: variable regions, constant regions; antigen-antibody binding; monoclonal antibodies
  • IB-NEW (HL) Autoimmune diseases: molecular mimicry; examples (lupus, MS, type 1 diabetes)
  • IB-NEW (HL) Allergen response: IgE, mast cells, histamine; anaphylaxis; immunotherapy
Experiments / Practical
  • Modelling the immune response: card-sorting activity — match antigens, B cells, antibodies, memory cells
  • Analysing blood glucose data: interpreting glucose tolerance test curves; diagnosing diabetes
  • Case study analysis: mRNA vaccines (COVID-19) — mechanism, safety data, global equity of distribution
ATL, LP & IB Dimensions
ATL Skills
🧠 ThinkingTracing the immune response from pathogen entry to memory cell formation — multi-step systems thinking
🔍 ResearchEvaluating vaccine safety data from clinical trials; understanding efficacy vs. effectiveness
Group debate on vaccine mandates and herd immunity — balancing individual rights and collective responsibility
IB Learner Profile
⚖️ PrincipledVaccine hesitancy: evaluating evidence vs. misinformation; scientific literacy as civic responsibility
❤️ CaringHIV/AIDS disproportionately affects sub-Saharan Africa — access to antiretroviral therapy as a justice issue
🌍 Open-mindedDifferent cultures have different relationships with vaccination — engaging with hesitancy respectfully
🌍 INTERNATIONAL MINDEDNESS
COVID-19 mRNA vaccines were developed by BioNTech (Germany/Turkey) and Moderna (USA) in record time — an international scientific collaboration. COVAX aimed to distribute vaccines equitably but high-income countries hoarded supply. HIV affects 38 million people globally, 70% in sub-Saharan Africa; antiretroviral therapy costs ~$100/year in generic form but was initially priced at ~$10,000. The TRIPS Agreement (WTO) and compulsory licensing: global health vs. patent rights.
🤖 ACADEMIC INTEGRITY & AI
AI can explain immune cell interactions and generate practice scenarios — valuable for preparation. Warning: AI-generated content about vaccines should always be verified against WHO/RKI sources, as this is an area where misinformation is prevalent. Facharbeit on immunology: AI assistance with literature search is acceptable with declaration.
M11 · Q2
Ecology & Climate Change
NRW-QIB-NEWIB-NEW (HL)
🧠 Thinking🔍 Research💬 Communication
❤️ Caring⚖️ Balanced🔎 Inquirer
SL 16 h · HL 22 h
IB Subtopics

Theme C C4.1 Populations & communities · C4.2 Transfers of energy and matter · Theme B B4.2 Ecological niches · Theme D D4.2 Stability and change · D4.3 Climate change

NRW Connection

Q-Phase Ökologie: Biotop/Biozönose, abiotische/biotische Faktoren, Toleranzkurven, Nahrungsnetz, Stoffkreislauf (C/N), Energiefluss, intra-/interspezifische Beziehungen, Treibhauseffekt, Biodiversität, Nachhaltigkeit. LK: r-/K-Strategien, exponentielles/logistisches Wachstum, hormonartig wirkende Substanzen, ökologischer Fußabdruck.

Content (with tags)
  • NRW-Q C4.1: Population growth models: exponential (J-curve) and logistic (S-curve, carrying capacity K)
  • NRW-Q Interspecific interactions: competition, predation, mutualism, parasitism, commensalism
  • NRW-Q (LK) r- and K-selection strategies; predator-prey cycles (Lotka-Volterra qualitative)
  • NRW-Q C4.2: Carbon cycle; nitrogen cycle; energy flow through trophic levels; ecological efficiency (10% rule)
  • NRW-Q D4.3: Greenhouse effect; enhanced greenhouse effect; evidence for anthropogenic climate change
  • IB-NEW B4.2: Fundamental vs. realised niche; competitive exclusion principle; character displacement
  • IB-NEW D4.2: Keystone species; trophic cascades; resilience and resistance of ecosystems
  • IB-NEW D4.3: Ocean acidification: CO₂ + H₂O → H₂CO₃; effects on calcification; coral bleaching
  • IB-NEW D4.3: Phenological shifts; range shifts; extinction risk from climate change
  • IB-NEW (HL) Simpson's diversity index D: calculation and interpretation; comparing habitats
  • IB-NEW (HL) Mark-recapture (Lincoln-Petersen) method for population size estimation
Experiments / Practical
  • Quadrat sampling: estimate plant species diversity; calculate Simpson's D (HL)
  • Mark-recapture simulation with beads: estimate population size; discuss assumptions (HL)
  • Climate change data analysis: IPCC temperature anomaly graphs; sea level rise; species range shift data
  • Fieldwork (if possible): school grounds habitat survey — abiotic factors and species distribution
ATL, LP & IB Dimensions
ATL Skills
🧠 ThinkingModelling trophic cascades: how removing a keystone species reshapes an entire ecosystem
🔍 ResearchInterpreting IPCC data; evaluating ocean acidification studies; designing fieldwork protocols
Group fieldwork: shared data collection, collaborative analysis, joint presentation
💬 CommunicationPresenting climate change evidence in a scientifically accurate and accessible way
IB Learner Profile
❤️ CaringBiodiversity loss and climate change are global justice issues — future generations bear the cost of present decisions
⚖️ BalancedWeighing economic development against ecological sustainability — NRW Bewertungskompetenz B12
🔎 InquirerFieldwork: generating original local biodiversity data; linking to global trends
🌍 INTERNATIONAL MINDEDNESS
The IPCC (Intergovernmental Panel on Climate Change) synthesises research from thousands of scientists worldwide — science as a global commons. Coral reef loss: the Great Barrier Reef (Australia) and the Coral Triangle (Indonesia/Philippines) are threatened by bleaching driven by emissions from largely different countries. Loss of biodiversity hits the Global South hardest. The CBD (Convention on Biological Diversity) and COP summits: who makes the rules? The concept of ecological debt: wealthy nations historically emitted more CO₂ — who owes what to whom?
🤖 ACADEMIC INTEGRITY & AI
AI can analyse climate datasets and generate ecosystem diagrams. Fieldwork data must be collected by students in person — AI cannot replace direct observation. For ecology IA: data collection protocols must be designed independently. AI assistance in writing up fieldwork results is acceptable with declaration and verification.
M12 · Q2
Human Evolution & Behaviour (LK) / Cancer & Gene Technology
NRW-QIB-NEW
🧠 Thinking🔍 Research💬 Communication
🌍 Open-minded⚖️ Principled🪞 Reflective
SL 8 h · HL 18 h
IB Subtopics

Theme A A4.1 Evolution and speciation (LK extension — Human evolution) · Theme D D1.3 Mutation and gene editing (Cancer extension)

NRW Connection

LK-Pflicht (nicht im GK): Humanevolution (Homo-Stammbäume, Fossilfunde, kulturelle Evolution, Werkzeuggebrauch, Sprachentwicklung); Sozialverhalten Primaten (exogene/endogene Ursachen, Fortpflanzungsverhalten). GK+LK: Krebs (Onkogene/Tumorsuppressorgene), personalisierte Medizin, Gentherapie vertieft.

Content — GK+SL track
  • NRW-Q Cancer biology: oncogenes (gain of function) vs. tumour suppressor genes (loss of function); p53
  • NRW-Q Multi-hit hypothesis; clonal evolution of cancer; metastasis
  • NRW-Q Personalised medicine: targeted therapy, immunotherapy (checkpoint inhibitors), CAR-T cells
  • IB-NEW CRISPR in cancer treatment: current clinical trials; somatic vs. germline editing distinction
Content — LK/HL extension
  • NRW-Q (LK) Human evolution: Homo habilis, H. erectus, H. heidelbergensis, H. neanderthalensis, H. sapiens — fossil evidence and molecular phylogeny
  • NRW-Q (LK) Out of Africa hypothesis; migration routes; interbreeding with Neanderthals (ancient DNA)
  • NRW-Q (LK) Cultural evolution: Lamarckian in character; tool use, fire, language; acceleration
  • NRW-Q (LK) Primate social behaviour: comparative study of great apes; cooperation, altruism, dominance hierarchies
  • IB-NEW Ancient DNA as evidence (Svante Pääbo, Nobel 2022): sequencing Neanderthal genome; archaic introgression
ATL, LP & IB Dimensions
ATL Skills
🧠 ThinkingEvaluating competing phylogenetic hypotheses for human origins using multiple lines of evidence
🔍 ResearchReading and evaluating primary papers on ancient DNA and human evolution (Pääbo lab, 2010–2022)
💬 CommunicationPresenting the cancer immunotherapy revolution; explaining clinical trial data to a non-specialist audience
IB Learner Profile
🌍 Open-mindedHuman evolution challenges simplistic narratives of linear progress; acknowledging complexity and uncertainty in the fossil record
⚖️ PrincipledSomatic gene therapy (treating existing patients) vs. germline editing (changing all future generations) — where is the ethical line?
🪞 ReflectiveWhat does human evolution tell us about who we are? Science and human identity — linking to Theory of Knowledge
🌍 INTERNATIONAL MINDEDNESS
Svante Pääbo (Sweden/Germany, Max Planck Institute) received the Nobel Prize 2022 for sequencing the Neanderthal genome — revealing that most non-African humans carry 1–4% Neanderthal DNA. The "Out of Africa" model integrates genetic evidence from populations worldwide. Human evolution is politically sensitive in some countries — how does cultural context affect the reception of scientific findings? CAR-T cell therapy: approved in USA/EU but costs $350,000+ per treatment — global inequity in cancer care.
🤖 ACADEMIC INTEGRITY & AI
Human evolution essays are a common Facharbeit topic — AI-generated content must be declared. Students must demonstrate independent understanding of the evidence in the Abschlussgespräch. Ancient DNA primary papers are complex; AI can help with comprehension but scientific reasoning must be the student's own.

6. NRW Bewertungskompetenz (B1–B12)

The Bewertungskompetenz is a mandatory NRW competency domain with no direct IB equivalent. It requires students to make reasoned ethical, ecological and socio-economic judgements. The table below maps each expectation to the modules where it is authentically developed.

CodeNRW Expectation (summary)Primary ModuleIB Bridge
B1Identify criteria for evaluation (ecological, ethical, economic, social)All modulesAO3 Evaluation; IA criterion 4
B2Apply criteria to biological issues (e.g. stem cells, gene therapy, energy)M4, M7, M10Extended response Paper 2
B3Distinguish descriptive from normative statements in biologyM7 (CRISPR), M8 (evolution)ToK link: fact vs. value
B4Critically assess sources and identify bias and interest conflictsM7, M10 (vaccines)Research Skills (ATL); IA background
B5Analyse short- and long-term consequences of biological applicationsM7, M11, M12IM blocks; sustainability
B6Weigh risks and benefits of biotechnology and medical interventionsM7, M10, M12Paper 2 ethical questions
B7Formulate and justify a personal position on controversial biological issuesM4, M7, M10IA Evaluation; Paper 2 extended response
B8Recognise multiperspectivity: scientific, cultural, religious, political viewsM4, M8, M10International Mindedness; Open-minded LP
B9Evaluate sustainable development in ecological and economic contextsM11, M12D4.3 Climate; A4.2 Biodiversity
B10Analyse consequences of human intervention in ecosystemsM11D4.2 Stability; C4.1 Populations
B11Assess individual and collective responsibility for health and environmentM10 (vaccines), M11Caring LP; Social Skills ATL
B12Evaluate sustainable development from ecological, economic, political and social perspectivesM11, M12D4.3; IM blocks throughout

Key Bewertung Contexts per Module

  • M4: Embryonic stem cells vs. adult vs. iPS — B2, B6, B7, B8
  • M7: CRISPR germline editing (He Jiankui) — B3, B5, B6, B7; Gene therapy access — B9, B12
  • M8: Evolution and cultural/religious worldviews — B3, B8; Conservation ethics — B9, B10
  • M10: Vaccine hesitancy and herd immunity — B4, B7, B11; HIV/AIDS access to treatment — B9, B12
  • M11: Climate change responsibility — B5, B9, B10, B12; Ecosystem management — B10
  • M12: Personalised cancer medicine and global equity — B6, B9, B12; Human evolution and identity — B3, B8

7. Collaborative Sciences Project (CSP)

The CSP is a compulsory IB component (~10 hours) conducted collaboratively across Biology, Chemistry and Physics. It is not externally assessed; students submit a 100-word reflection. Its primary purpose is to develop interdisciplinary scientific thinking and social ATL skills.

CSP Timeline

PhaseTimingActivity
PlanningEF, Term 2Coordinate with Chemistry and Physics teachers; agree on interdisciplinary theme (e.g. water quality, food science, climate systems, biofuels)
InvestigationEF/Q1 transition (~10 h)Students work in mixed-subject groups to collect, analyse and interpret data; each discipline contributes its specific tools and perspective
ReflectionQ1, wk 1–2Individual 100-word reflection submitted; focuses on interdisciplinary connections and how perspectives complemented each other

Suggested CSP Themes (Biology ↔ Chemistry link)

  • Water quality: Biology (aquatic biodiversity, bacteria), Chemistry (pH, heavy metals, nitrates), Physics (turbidity measurement) — links M2 (water), M11 (ecology), Chemistry Seq 4 (acids/bases)
  • Biofuels: Biology (yeast fermentation, plant biology), Chemistry (combustion enthalpy, atom economy), Physics (energy efficiency) — links M6 (respiration), Chemistry Seq 3 (energetics) and Seq 6 (Green Chemistry)
  • Food science: Biology (enzymes, digestion), Chemistry (biochemistry, food additives), Physics (calorimetry) — links M3 (enzymes), Chemistry Seq 3
  • Climate systems: Biology (ecosystem carbon cycle), Chemistry (greenhouse gases, ocean acidification), Physics (radiation) — links M11, Chemistry Seq 7
🤖 CSP and AI: AI tools may be used for data analysis and literature research within the CSP, with appropriate declaration. The collaborative process, experimental design and student reflection must be authentic. The 100-word reflection must be the individual student's own writing.

8. NRW-Specific Content (LK) without IB Equivalent

The following content is mandatory in the NRW Leistungskurs (LK) but has no systematic IB parallel. It is taught in addition to the IB modules and is assessed in the NRW Zentralabitur.

NRW TopicModuleKey ContentIB Closest Link
HumanevolutionM12 (LK)Homo habilis, H. erectus, H. heidelbergensis, H. neanderthalensis, H. sapiens; fossil evidence; Out of Africa; ancient DNA (Pääbo); cultural evolution; tool use; languageA4.1 (Evolution) — extended context only
Sozialverhalten PrimatenM12 (LK)Comparative study of great ape behaviour; exogene/endogene Ursachen; Fortpflanzungsverhalten; Altruismus; Dominanzhierarchien; Vergleich mit menschlichem VerhaltenNot in IB
Neurophysiologische VerfahrenM9 (LK)EEG, fMRI, PET, MEG — Möglichkeiten und Grenzen; Neuroenhancement; neurophysiologische Grundlagen von Lernstörungen; Plastizität im KontextC2.2 (neural signalling) — basic only
Hormonartig wirkende SubstanzenM11 (LK)Xenoöstrogene (z.B. BPA, Pestizide); Auswirkungen auf Reproduktion und Entwicklung; Ökotoxikologie; Bewertung (B5, B6)C2.1 (chemical signalling) — principle only
Zelluläre LernprozesseM9 (LK)Hebb'sche Synapse; LTP (Langzeitpotenzierung); Habituation; Sensitivierung; molekulare Grundlagen des Gedächtnisses; DemenzC2.2.4 (LTP) — HL already covers this
Krebs / Personalisierte MedizinM12 (GK+LK)Onkogene, Tumorsuppressorgene (p53, Rb); Multi-Hit-Hypothese; Checkpoint-Inhibitoren; CAR-T-Therapie; Gentherapie; ethische BewertungD1.3 (mutation), B2.3 (cell specialization) — partial

These topics are taught during M9 and M12 extensions and are assessed in NRW Klausuren with AFB III / Bewertungskompetenz emphasis. IB students benefit from this additional depth even though it is not tested in IB examinations.

9. Cross-Subject Conceptual Links: Biology ↔ Chemistry

The IB requires that conceptual links between Group 4 subjects are explicitly integrated into the curriculum. The following table maps the most significant overlaps between the Biology modules and the Chemistry sequences. These connections are taught in parallel or in sequence and form the basis for the Collaborative Sciences Project (CSP).

Concept Biology Module Chemistry Sequence Shared Depth IB Themes / Subtopics
Water & Hydrogen Bonding M2 – Biomolecules & Membranes (A1.1) Seq 1 – Atombau & Bindungsmodelle (S2.2) Bio: biological roles, surface tension, cohesion. Chem: H-bonds as IMF, electronegativity, boiling point anomaly A1.1 ↔ S2.2.8/9
Condensation & Hydrolysis M2 – Biomolecules (A1.1.3, B1.1.1–3, B1.2.1) Seq 8 – Organische Reaktionswege (R3.4, Veresterung) Bio: peptide bonds, glycosidic bonds, ester bonds in lipids. Chem: esterification as condensation; nucleophilic substitution; hydrolysis equilibrium B1.1.3, B1.2.1 ↔ R3.4
Enzyme Kinetics & Catalysis M3 – Cellular Metabolism (C1.1.1–3) Seq 6 – Reaktionskinetik (R2.2) Bio: active site, Michaelis-Menten (HL), inhibition types. Chem: E_a reduction, activation energy diagrams, rate equations (HL). Both: temperature and concentration effects on rate C1.1 ↔ R2.2.5 / R2.2.9–13 (HL)
ATP & Energy Transfer M3, M5, M6 – Metabolism, Photosynthesis, Respiration (C1.1–1.3) Seq 3 – Energetik (R1.1–1.4) Bio: ATP as energy currency; ΔG of hydrolysis drives biosynthesis; chemiosmosis. Chem: enthalpy, Gibbs energy (HL), spontaneity. Key link: ΔG < 0 for spontaneous reactions → ATP coupling makes non-spontaneous reactions possible C1.2, C1.3 ↔ R1.1–1.4 (HL)
Redox Reactions M6 – Cellular Respiration (C1.2: NAD⁺/NADH, FAD/FADH₂, ETC) Seq 5 – Elektrochemie (R3.2) Bio: biological electron carriers; ETC as redox cascade; O₂ as final electron acceptor. Chem: half-equations, standard electrode potentials, E°, ΔG = −nFE°. Key link: same electron transfer logic, different molecular machinery C1.2.3 ↔ R3.2.1–2.4 / R3.2.6 (HL)
Acid-Base Chemistry M3, M10 – Enzymes, Homeostasis (pH optima; blood pH; kidney) Seq 4 – Säuren, Basen & Puffer (R3.1) Bio: enzyme denaturation at non-optimal pH; blood pH 7.35–7.45; bicarbonate buffer system; kidney tubule H⁺ secretion. Chem: K_a, Henderson-Hasselbalch, buffer calculations, titration curves. Key link: blood as a biological buffer — exact same chemistry C3.1, C3.2 ↔ R3.1.1–3.1.15 (HL)
Photosynthesis & CO₂ Chemistry M5 – Photosynthesis (C1.3: Calvin cycle, CO₂ fixation) Seq 7 – Chemisches Gleichgewicht (R2.3: Haber-Bosch); Seq 3 (R1.3: Biofuels) Bio: RuBisCO fixes CO₂; Calvin cycle produces G3P; C4 plants avoid photorespiration. Chem: CO₂ as reactant/product in equilibrium systems; ocean acidification (CO₂ + H₂O → H₂CO₃). Also: biofuels — combustion enthalpy (Chem Seq 3) vs. fermentation (Bio M6) C1.3 ↔ R2.3, R1.3, D4.3
Organic Functional Groups & Biomolecules M2 – Biomolecules (B1.1, B1.2: carbohydrates, lipids, proteins, nucleic acids) Seq 2 – Funktionelle Gruppen (S3.2); Seq 8 – Organische Reaktionswege (R3.3–3.4) Bio: –OH (alcohols/sugars), –COOH (fatty acids, amino acids), –NH₂ (amino acids, bases), phosphate. Chem: IUPAC nomenclature; functional group reactions. Key link: amino acids contain –NH₂ and –COOH → peptide bond = amide bond (Chemistry IF 3) B1.1, B1.2 ↔ S3.2, R3.3–3.4
Polymers M2, M7 – Biomolecules & Genetics (B1.1–B1.2: polysaccharides, proteins; D1.1–D1.2: DNA, RNA) Seq 9 – Moderne Werkstoffe (S2.4: Polymere, Polykondensation) Bio: biological polymers (polysaccharides, proteins, nucleic acids) form by condensation. Chem: synthetic polymers (polyamide/nylon = same amide bond as peptide; polyester = same ester bond as lipids). Key link: identical bond chemistry, different monomers B1.1, B1.2, D1.1 ↔ S2.4.5–6
Spectroscopy & Molecular Analysis M7 – Molecular Genetics (bioinformatics; gel electrophoresis as separation technique) Seq 10 – Spektroskopie (S3.2.8–12 HL: MS, IR, ¹H-NMR) Bio: gel electrophoresis separates DNA by size (like chromatography). Chem HL: MS identifies molecular mass and fragments; IR identifies functional groups; NMR gives structural detail. Cross-application: forensic DNA profiling uses both electrophoresis (Bio) and MS (Chem) D1.1 ↔ S3.2.8–12 (HL)
Green Chemistry & Sustainability M11 – Ecology & Climate Change (D4.3: CO₂, ocean acidification) Seq 6 – Reaktionskinetik (R2.1.5: Atom Economy); Seq 3 (R1.3: biofuels, fuel cells) Bio: carbon cycle; ecosystem effects of chemical pollutants; biodegradable vs. persistent compounds. Chem: atom economy as measure of synthetic efficiency; biofuels; Green Chemistry principles. Key link: both disciplines assess sustainability through different lenses C4.2, D4.3 ↔ R2.1.5, R1.3
Membrane Chemistry & Electrochemistry M2, M9 – Membranes & Neural Signalling (B2.1: transport; C2.2: Na⁺/K⁺ pump, ion channels) Seq 5 – Elektrochemie (R3.2: electrochemical gradients, ion transport, Nernst) Bio: Na⁺/K⁺ pump creates electrochemical gradient → resting potential. Chem HL: Nernst equation relates ion concentration to potential. Key link: the resting potential IS an electrochemical potential — same physics, biological context B2.1, C2.2 ↔ R3.2.4–6 (HL)
Nitrogen Chemistry M11 – Ecology (C4.2.2: nitrogen cycle — fixation, nitrification, denitrification) Seq 7 – Chemisches Gleichgewicht (R2.3: Haber-Bosch synthesis of NH₃) Bio: bacteria fix N₂ → NH₃ (same reaction as Haber-Bosch, but enzymatic); nitrifying bacteria oxidise NH₃ → NO₃⁻. Chem: N₂ + 3H₂ ⇌ 2NH₃ as equilibrium; industrial conditions; Le Chatelier. Key link: nitrogen cycle is the ecological consequence of the same chemistry studied in Seq 7 C4.2.2 ↔ R2.3 (Haber-Bosch)
CRISPR & Molecular Biology Tools M7 – Molecular Genetics (D1.3.2–3: CRISPR-Cas9; D1.1.2: DNA fidelity) Seq 10 (HL) – Spektroskopie; Seq 7 – Gentechnik context Bio: CRISPR uses RNA-DNA base pairing specificity; Cas9 is an enzyme (nuclease); repair pathways. Chem: nucleotide structure (A1.2); base pairing rules; enzyme as catalyst (C1.1). Cross-context: same molecular tools underlie both the analytical (Chem: PCR, gel electrophoresis) and editing (Bio: CRISPR) applications D1.3 ↔ A1.2, C1.1

Timing of Cross-Subject Teaching

The following modules run approximately in parallel and should be coordinated between Biology and Chemistry teachers:

PhaseBiologyChemistryKey Shared Concept
EFM2 BiomoleculesSeq 1 (Bindungsmodelle), Seq 2 (Funktionelle Gruppen)H-bonds; condensation reactions; functional groups
EFM3 EnzymesSeq 6 (Kinetik — Stoßtheorie, E_a, Katalysator)Activation energy; catalysis; effect of T and concentration
Q1.1M5 PhotosynthesisSeq 3 (Energetik — Enthalpie, Gibbs)Energy transfer; ΔG; ATP; chemiosmosis
Q1.1M6 RespirationSeq 5 (Elektrochemie — Redox)Electron transfer; NAD/FAD as bio-electrochemical carriers
Q1.2M7 Molecular GeneticsSeq 8 (Organische Reaktionswege)Peptide bond = amide bond; polymer chemistry
Q2.1M9 Neural SignallingSeq 4 (Säuren/Basen — Puffer)Blood pH buffer; enzyme pH optima; membrane potentials
Q2.2M11 EcologySeq 7 (Gleichgewicht — Haber-Bosch)Nitrogen cycle; CO₂ equilibrium; ocean acidification
🌍 INTERNATIONAL MINDEDNESS — Cross-Subject
The most significant global challenges — climate change, food security, pandemic response, cancer treatment — all require simultaneous understanding of biology AND chemistry. The IB's cross-subject requirement reflects the reality that no major scientific problem is solved within a single discipline. The Nobel Prize in Chemistry 2020 (CRISPR) required understanding of both molecular biology and nucleic acid chemistry. The Nobel Prize in Chemistry 2023 (quantum dots for bioimaging) linked physics, chemistry and biology.

10. International Mindedness

International Mindedness is embedded in every module through a dedicated 🌍 block. The following guiding principles apply across all teaching:

  • Science as a global endeavour: Nearly all major biological discoveries involve international collaboration. Who receives credit, funding and access?
  • Global consequences of biology: Vaccines, gene therapies, agricultural biotechnology and climate mitigation all have planetary-scale implications that are unevenly distributed.
  • Unequal access: From antiretroviral drugs to CAR-T cell therapy, biological innovation is often accessible only in wealthy nations.
  • Science and culture: Evolution, stem cell research and genetic testing intersect with religion, law and cultural identity — engaging with sensitivity and scientific rigour.

Cross-subject conceptual links (Biology ↔ Chemistry ↔ Physics) will be added once the Chemistry and Physics curricula are aligned.

11. Academic Integrity & AI Use

The school treats AI as a tool that must be used with competence and declared transparently. AI literacy is part of the ATL dimensions Research Skills and Thinking Skills.

Three Levels of AI Use

LevelContextAI UseDeclaration
1 – Learning toolSelf-study, revision, practiceUnrestrictedNot required
2 – Work toolHomework, Facharbeit, reportsPermitted with declarationTool, prompt, how used
3 – No AIIA, Klausuren, AbiturNot permittedIBO Academic Integrity Policy applies

Facharbeit

AI use in the Facharbeit is permitted but must be fully declared. A concluding discussion (Abschlussgespräch) with the teacher verifies that the student has independently understood the content.

🤖 Principle: AI can structure and phrase. Biological understanding — the why behind mechanisms, the logic of data interpretation, the ethical reasoning — must be the student's own. The Abschlussgespräch makes the difference visible.

Governing Documents

  • IBO Academic Integrity Policy (current version)
  • School-wide AI and Academic Integrity Policy
  • NRW regulations on the Facharbeit (§ 14 APO-GOSt)

12. Assessment

12.1 Double Assessment Culture

SemesterKlausur 1 (NRW style)Klausur 2 (IB style)
EFZellbiologie (Operatoren, 4 AFB, Bewertung Stammzellen)Paper 2 mix: M1+M2 short answer + data-based
Q1.1Stoffwechselphysiologie (Photosynthese)Paper 1B data-based: photosynthesis limiting factors
Q1.2Genetik & Evolution (Replikation, Translation, Mutation)Paper 2: M7 protein synthesis + M8 evolution extended response
Q2.1Neurobiologie (Aktion-/Ruhepotenzial, Synapse)Paper 2: M9 neural signalling + M10 immunity
Q2.2Ökologie + Genetik/Evolution (Bewertung)Paper 2: M11 ecology extended + Paper 1B data analysis

12.2 IB External Examination

ComponentSLHLWeighting
Paper 1A (40 MCQ) + Paper 1B (data-based)1 h 452 h 1536 %
Paper 2 (data + extended response)1 h 452 h 3044 %
Internal Assessment (Scientific Investigation)10 h10 h20 %

13. Internal Assessment (IA) — Timeline

PhaseTimingActivityIA Criterion
IntroductionEF, wk 4–6IA format, criteria, example IAs; exploring research question areaspreparatory
Research QuestionEF end / Q1 start1-page proposal: question, hypothesis, variables, method; teacher feedbackResearch Design (prep)
Data CollectionQ1~10 h class time; raw data secured and digitisedResearch Design
AnalysisQ1 / Q2 transitionStatistical analysis (mean, SD, t-test / χ²); graphs; uncertaintyData Analysis
Write-upQ2.1Draft all sections; peer review; revision; max 3,000 wordsConclusion + Evaluation
SubmissionQ2.2, ~8 wks before AbiFinal submission; internal marking; IBO moderationAll 4 criteria (6 pts each)

13.1 Suggested IA Topics by Module

  • M3: Effect of pH on amylase activity (enzyme kinetics)
  • M5: Effect of light wavelength on the rate of photosynthesis (leaf disc assay)
  • M6: Effect of temperature on yeast CO₂ production (fermentation)
  • M8: Comparing biodiversity (Simpson's D) in two local habitats (fieldwork)
  • M9: Effect of caffeine / exercise on reaction time (neurophysiology)
  • M11: Effect of salt concentration on germination rate (ecology / homeostasis)

14. Command Terms DE / EN

NRW Operator (DE)IB Command Term (EN)AFBExpected performance
nennen, beschreibenstate, describe, listIRecall and present factual information
erläutern, erklärenexplain, outlineIIGive reasons; show cause-and-effect
begründenjustify, deduceII–IIISupport a conclusion with evidence
vergleichencompare and contrastIISimilarities and differences with structure
auswertenanalyse, evaluateII–IIIInterpret data; draw conclusions
beurteilen / bewertenevaluate, assessIIIReasoned judgement against criteria
entwickeln / entwerfendesign, suggest, proposeIIIOriginal planning or hypothesis
ableitendeduce, predictII–IIILogical inference from given information
berechnencalculate, determineI–IIQuantitative result with working shown
skizzierensketch, draw, labelI–IIAnnotated visual representation

15. Appendix & Sources

15.1 Governing Documents

  • IBO (2023): Diploma Programme Biology Guide. First Assessment May 2025.
  • MSB NRW (2022): Kernlehrplan für die Gymnasiale Oberstufe — Biologie. Erlass vom 31.05.2022.
  • MSB NRW (2019): Kernlehrplan für die Sekundarstufe I (G9) — Biologie.
  • IBO (2024): Subject Brief — Sciences: Biology.

15.2 Recommended Resources

  • Allott, A. & Mindorff, D. (2023): IB Biology Course Book 2nd ed. Oxford University Press.
  • Damon, A. et al. (2023): Biology for the IB Diploma. Cambridge University Press.
  • Campbell, N.A. et al. (2021): Biology, 12th ed. Pearson. (reference text)
  • Linder, B. et al. (2023): Biologie heute entdecken — Oberstufe NRW. Schroedel.
  • biologyforlife.com; ib.bioninja.com.au; savemyexams.com/ib-biology (for IB subtopic reference)

Version: May 2026 · This document is a working curriculum framework. Cross-subject links (Biology ↔ Chemistry ↔ Physics) will be added when all three curricula are aligned. Formal IB World School authorisation requirements must be met separately.

90 Understandings SL = Standard Level  |  HL = Higher Level (AHL) Click any understanding to see module mapping
Theme A Unity and Diversity
A1 Molecules — Water & Nucleic Acids
A1.1.1 Water is a polar molecule that forms hydrogen bonds with other water molecules and with polar solutes.Cohesion, adhesion, surface tension, high specific heat capacity, solvent properties SLM2
A1.1.2 The properties of water that make it suitable for life include its thermal properties, solvent properties and cohesion.High specific heat, latent heat of vaporization, density of ice < liquid water SLM2
A1.2.1 Nucleotides consist of a pentose sugar, a phosphate group and a nitrogenous base; nucleotides join by phosphodiester bonds.Deoxyribose vs. ribose; purines (A,G) vs. pyrimidines (C,T,U); 3'–5' phosphodiester bonds SLM2
A1.2.2 DNA is a double helix of two antiparallel strands held together by hydrogen bonds between complementary base pairs.A–T (2 H-bonds), G–C (3 H-bonds); Watson-Crick model; X-ray crystallography evidence SLM2
A1.2.3 RNA is a single-stranded polynucleotide; different types (mRNA, tRNA, rRNA) have distinct roles.Uracil instead of thymine; ribose sugar; shorter and functional diversity SLM2
A1.1.3 Monomers are linked into polymers by condensation reactions and broken down by hydrolysis.Water released in condensation (–OH + H–); water used in hydrolysis; applies to carbohydrates, proteins, nucleic acids, lipids SLM2
A2 Cells — Structure, Origins & Viruses
A2.1.1 The origin of life required the formation of self-replicating molecules that could contain heritable information.RNA-world hypothesis; Miller-Urey experiment; protocells; conditions on early Earth HLM1
A2.1.2 The first eukaryotic cells may have evolved from prokaryotes by endosymbiosis.Evidence: own circular DNA, 70S ribosomes, double membrane, binary fission of organelles HLM1
A2.2.1 Cells can be prokaryotic or eukaryotic; all share certain features but differ in complexity.Prokaryote: no nucleus, 70S ribosomes, plasmids, cell wall (peptidoglycan); Eukaryote: nucleus, 80S ribosomes, membrane-bound organelles SLM1
A2.2.2 Eukaryotic cells contain membrane-bound organelles with specialized functions.Mitochondria (ATP), RER (protein secretion), Golgi (modification/packaging), lysosome (digestion), vacuoles SLM1
A2.2.3 Microscopy is used to observe cells; magnification and resolution determine what can be seen.Magnification = image size / actual size; resolution; light vs. TEM vs. SEM; scale bars SLM1
A2.3.1 Viruses are non-cellular entities that can only replicate inside living host cells.Capsid, nucleic acid (DNA or RNA), envelope; lytic vs. lysogenic cycles; retroviruses (reverse transcriptase) HLM10
A2.3.2 HIV is a retrovirus that uses reverse transcriptase to convert its RNA genome into DNA.HIV life cycle: binding → fusion → reverse transcription → integration → transcription → budding HLM10
A2.2.4 As cells increase in size, the surface area to volume ratio decreases, limiting the rate of exchange with the environment.Calculate SA:V; small cells exchange faster; reason cells are microscopic; model with cubes SLM1
A3 Organisms — Diversity & Classification
A3.1.1 Organisms are classified into a hierarchy of taxa based on shared characteristics.Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species; binomial nomenclature (italicised) SLM8
A3.1.2 The three-domain system (Bacteria, Archaea, Eukarya) is based on rRNA sequence comparisons.Woese and Fox (1977); Archaea more closely related to Eukarya; extremophiles in Archaea SLM8
A3.1.3 Species are groups of organisms that can interbreed and produce fertile offspring under natural conditions.Biological species concept; limitations (asexual organisms, ring species, fossils) SLM8
A3.2.1 Cladistics classifies organisms using shared derived characters (synapomorphies) to construct cladograms.Character matrix; parsimony principle; molecular clock; clade vs. grade HLM8
A3.2.2 Molecular data (DNA/protein sequences) can be used to determine phylogenetic relationships.Molecular clock; cytochrome c comparisons; rRNA as marker; overturning morphological classification HLM8
A3.2.3 Groups can be monophyletic (valid clade), paraphyletic or polyphyletic; only monophyletic groups are accepted in cladistics.Reptilia (traditional) = paraphyletic; birds excluded — example of reclassification HLM8
A4 Ecosystems — Evolution & Conservation
A4.1.1 Evidence for evolution comes from the fossil record, comparative anatomy, molecular biology and biogeography.Vestigial structures; homologous vs. analogous structures; cytochrome c data; continental drift SLM8
A4.1.2 Natural selection acts on heritable variation to change allele frequencies over time.Variation (mutation, sexual reproduction); heritability; differential survival/reproduction; adaptation SLM8
A4.1.3 Speciation is the formation of new species by accumulation of differences until reproductive isolation is complete.Allopatric (geographic barrier) vs. sympatric; prezygotic and postzygotic isolation mechanisms SLM8
A4.2.1 Biodiversity can be assessed at genetic, species and ecosystem levels; habitat loss is the primary threat.IUCN categories; hotspots; invasive species, overexploitation, pollution, climate change as threats SLM8
A4.2.2 Conservation strategies include in situ (protected areas) and ex situ (captive breeding, seed banks) approaches.Cost-benefit of conservation; ecosystem services; rewilding; CBD goals SLM8
A4.2.3 Simpson's diversity index (D) quantifies biodiversity by accounting for both species richness and evenness.D = 1 − Σ(n/N)²; higher D = more diverse; compare habitats; interpret changes over time HLM11
A4.1.4 Coevolution occurs when two or more species exert selection pressure on each other, driving reciprocal evolutionary change.Pollinator-flower matching; host-parasite arms race; mimicry; ant-acacia mutualism SLM8
Theme B Form and Function
B1Molecules — Carbohydrates, Lipids & Proteins
B1.1.1Carbohydrates serve as energy sources and structural components; their properties relate to their structure.Glucose isomers (α/β); glycosidic bonds; starch (energy), glycogen (storage), cellulose (structure)SLM2
B1.1.2Lipids include triglycerides (energy storage) and phospholipids (membrane structure); saturated vs. unsaturated.Ester bonds; high energy:mass ratio; phospholipid bilayer formation; sterols (cholesterol)SLM2
B1.2.1Proteins are polymers of amino acids linked by peptide bonds; their structure has four levels.R-group variation; primary (sequence), secondary (α-helix, β-sheet), tertiary (3D), quaternary (subunits)SLM2
B1.2.2Protein function is determined by 3D shape; denaturation disrupts function by altering shape.Heat, pH, heavy metals denature; enzyme active site; antibody specificity; haemoglobin quaternary structureSLM2
B1.1.3 Triglycerides are formed by condensation of glycerol with three fatty acids via ester bonds; hydrolysis by lipase reverses this.Emulsification by bile salts; lipase activity in digestion; fatty acid chain length and saturation affect properties SLM2
B2Cells — Membranes, Organelles & Specialization
B2.1.1The fluid-mosaic model describes the plasma membrane as a dynamic phospholipid bilayer with embedded proteins.Integral vs. peripheral proteins; glycoproteins; cholesterol fluidity; Singer-Nicolson modelSLM2
B2.1.2Substances cross membranes by simple diffusion, facilitated diffusion, osmosis, active transport and vesicle transport.Concentration gradient; channel/carrier proteins; ATP-dependent active transport; bulk transportSLM2
B2.2.1Membrane-bound organelles allow compartmentalization of incompatible chemical reactions.Lysosomes (acid hydrolases); peroxisomes (H₂O₂); mitochondria (oxidative phosphorylation)SLM1
B2.2.2The endomembrane system (ER, Golgi, vesicles) processes and directs proteins and lipids.Rough ER → Golgi → secretory vesicle → exocytosis; signal peptide targetingSLM1
B2.3.1Cell specialization arises from differential gene expression, not differences in DNA sequence.Totipotent (zygote), pluripotent (ESC), multipotent (adult); transcription factor combinationsSLM4
B2.3.2Induced pluripotent stem cells (iPS) can be generated by reprogramming adult somatic cells with Yamanaka factors.Oct4, Sox2, Klf4, c-Myc; ethical advantage over embryonic stem cells; current clinical trialsHLM4
B2.2.3 The cytoskeleton of actin filaments and microtubules gives cells shape, enables movement and organises organelles.Actin → microfilaments (pseudopodia, cytokinesis); tubulin → microtubules (spindle, cilia, flagella); kinesin/dynein motors SLM1
B2.1.3 Membrane permeability depends on the polarity, size and lipid solubility of molecules; temperature affects fluidity.Non-polar / small molecules cross freely; larger polar molecules need protein channels; cholesterol buffers fluidity changes SLM2
B3Organisms — Gas Exchange, Transport & Motility
B3.1.1Gas exchange surfaces have large surface area, short diffusion distance, maintained concentration gradient and moist surface.Alveoli (mammals): surfactant, capillaries; Fish gills: counter-current exchange; insects: tracheaeSLM6
B3.2.1Haemoglobin's S-shaped oxygen dissociation curve reflects cooperative binding; the Bohr effect facilitates O₂ release in tissues.Partial pressure O₂; cooperative binding; CO₂/H⁺ shifts curve right (Bohr); fetal Hb higher affinitySLM6
B3.2.2Plants transport water through xylem (cohesion-tension) and assimilates through phloem (mass flow from source to sink).Transpiration pull; apoplast/symplast pathways; companion cells and sieve tubes; pressure flow hypothesisSLM6
B3.3.1Muscle contraction involves the sliding of actin and myosin filaments; myosin heads use ATP hydrolysis to generate force.Sarcomere structure; Z-disc, H-zone, A-band, I-band; power stroke; rigor mortis (no ATP)HLM6
B3.3.2The neuromuscular junction translates neural signals into muscle contraction via Ca²⁺ and troponin-tropomyosin regulation.ACh → EPSP → depolarization → Ca²⁺ release from SR → troponin shifts → active sites exposedHLM6
B3.2.3 Blood transports O₂ (in erythrocytes as oxyhaemoglobin), CO₂ (mainly as bicarbonate in plasma), nutrients, hormones and wastes.CO₂ transport: 70% as HCO₃⁻ (chloride shift), 23% carbaminohaemoglobin, 7% dissolved; plasma proteins SLM6
B3.1.2 Ventilation maintains concentration gradients across gas exchange surfaces by renewing the air or water in contact with them.Tidal volume, vital capacity, residual volume; diaphragm + intercostal muscles; fish operculum; insect spiracles SLM6
B4Ecosystems — Adaptation & Niches
B4.1.1Organisms show adaptations — inherited traits that increase fitness in their environment.Structural, physiological and behavioural adaptations; C4 plants, xerophytes, deep-sea organismsSLM5
B4.2.1An ecological niche is the role and position of a species in its ecosystem; competitive exclusion limits niche overlap.Fundamental vs. realised niche; Gause's experiment; character displacement; resource partitioningSLM11
B4.2.2 Character displacement reduces competition between species by driving divergence in resource use when species overlap in range.Darwin's finches beak sizes; anole lizard perch height; sympatric divergence greater than allopatric populations SLM11
B4.1.2 Xerophytes have structural and physiological adaptations to reduce water loss and maximise water uptake in arid environments.Thick cuticle; sunken stomata; rolled leaves; CAM metabolism; deep/extensive roots; small leaf area; succulent stems SLM5
Theme C Interaction and Interdependence
C1Molecules — Enzymes, Respiration & Photosynthesis
C1.1.1Enzymes are biological catalysts with a specific active site that binds substrates; they lower activation energy.Lock-and-key vs. induced-fit; enzyme-substrate complex; enzyme not consumed; globular proteinSLM3
C1.1.2Enzyme activity is affected by temperature, pH, substrate concentration and inhibitors.Optimum T and pH; denaturation; competitive vs. non-competitive inhibition; allosteric regulationSLM3
C1.1.3Michaelis-Menten kinetics describe the relationship between substrate concentration and reaction rate (Km and Vmax).Km = [S] at ½Vmax; low Km = high affinity; competitive inhibitor raises apparent Km; non-competitive lowers VmaxHLM3
C1.2.1Glycolysis converts glucose to pyruvate in the cytosol, producing a net gain of 2 ATP and 2 NADH.10-step pathway; investment phase (2 ATP); payoff phase (4 ATP); substrate-level phosphorylationSLM6
C1.2.2The Krebs cycle in the mitochondrial matrix oxidises acetyl-CoA, generating NADH, FADH₂, CO₂ and ATP.Pyruvate → acetyl-CoA (PDC); 2 turns per glucose; 6 NADH, 2 FADH₂, 2 ATP per glucose from TCASLM6
C1.2.3The electron transport chain generates a proton gradient that drives ATP synthesis via chemiosmosis.NADH/FADH₂ donate electrons; O₂ final acceptor → H₂O; ~32 ATP per glucose total; cristae increase surface areaSLM6
C1.2.4Anaerobic respiration regenerates NAD⁺ without O₂; products are lactate (animals) or ethanol + CO₂ (yeast).Only 2 ATP net; lactate in muscle → liver (Cori cycle); fermentation applications; RQ = CO₂/O₂ consumedSLM6
C1.3.1In the light-dependent reactions, chlorophyll absorbs light energy to split water, produce ATP and NADPH.Photosystem II (water splitting, O₂ released); electron transport; photosystem I (NADPH production)SLM5
C1.3.2The Calvin cycle in the stroma uses ATP and NADPH to fix CO₂ into G3P; RuBP is regenerated.RuBisCO enzyme; 3 CO₂ → 1 G3P (net); 9 ATP + 6 NADPH per G3P; G3P → glucose, starch, sucroseSLM5
C1.3.3Factors limiting photosynthesis include light intensity, CO₂ concentration and temperature.Blackman's law (most limiting factor); compensation point; saturation point; graphical analysisSLM5
C1.3.4Chemiosmosis in thylakoids produces ATP via a proton gradient across the thylakoid membrane.Cyclic vs. non-cyclic photophosphorylation; light-harvesting complexes (antenna pigments); CF₁-CF₀ ATP synthaseHLM5
C1.3.5C4 plants spatially separate initial CO₂ fixation from the Calvin cycle, reducing photorespiration in hot conditions.PEP carboxylase (high affinity for CO₂); bundle sheath + mesophyll cells; maize, sugarcaneHLM5
C1.2.5 The theoretical yield of aerobic respiration is approximately 30–32 ATP per glucose; actual yield is lower due to membrane leakage and transport costs.Glycolysis: 2 ATP; TCA: 2 ATP; ETC: ~26–28 ATP; efficiency ~40%; heat as byproduct; compare to combustion SLM6
C2Cells — Neural & Chemical Signalling
C2.1.1Chemical signals (hormones) bind to receptors to trigger cell responses; mechanisms differ for peptide vs. steroid hormones.Peptide hormones: membrane receptor, second messenger (cAMP, IP₃); steroid hormones: intracellular receptor, gene expressionHLM9
C2.1.2Signal transduction pathways amplify chemical signals through cascades of molecular interactions.G-protein coupled receptors; kinase cascades; signal amplification; cross-talk between pathwaysHLM9
C2.2.1Neurons maintain a resting potential (−70 mV) using the Na⁺/K⁺ pump and selective ion permeability.3 Na⁺ out, 2 K⁺ in per cycle; K⁺ leak channels; polarization maintained at restSLM9
C2.2.2An action potential is an all-or-nothing depolarisation propagated along the axon membrane.Threshold (−50 mV); voltage-gated Na⁺ channels open; depolarisation; K⁺ channels open; refractory periodSLM9
C2.2.3At chemical synapses, neurotransmitters are released by exocytosis and bind to postsynaptic receptors.Ca²⁺ trigger; EPSP; ACh (excitatory), GABA (inhibitory); reuptake/enzymatic breakdown; drug effectsSLM9
C2.2.4Postsynaptic potentials summate (spatially and temporally); long-term potentiation underlies learning.Hebb's rule; LTP; AMPA/NMDA receptors; spatial summation (multiple synapses); temporal summationHLM9
C3Organisms — Body Systems & Defence
C3.1.1Body systems maintain homeostasis through negative feedback loops involving receptors, control centres and effectors.Blood glucose: insulin (β cells) ↑ uptake; glucagon (α cells) ↑ glycogen breakdown; thermoregulation: ecto- vs. endothermsSLM10
C3.2.1Innate immunity provides non-specific, rapid defences including physical barriers, phagocytosis and inflammation.Skin (keratin); mucus/cilia; phagocytes (neutrophils, macrophages); mast cells; natural killer cells; feverSLM10
C3.2.2Adaptive immunity produces antigen-specific responses via B and T lymphocytes; immunological memory enables rapid secondary responses.Clonal selection; plasma cells (antibodies); T helper (Th) and T cytotoxic (Tc) cells; memory B and T cellsSLM10
C3.2.3Vaccination stimulates adaptive immunity without causing disease; herd immunity protects vulnerable individuals.Types: live-attenuated, killed, subunit, mRNA; active vs. passive immunity; herd immunity thresholdSLM10
C3.2.4Antibodies are Y-shaped glycoproteins with variable antigen-binding sites; monoclonal antibodies have diagnostic and therapeutic uses.Heavy/light chains; disulfide bonds; Fab (antigen binding) and Fc (effector function); ELISA; HerceptinHLM10
C3.2.5Allergies involve inappropriate IgE-mediated responses to harmless antigens; autoimmune diseases involve self-antigen attack.IgE → mast cell sensitisation → histamine release; anaphylaxis; Type 1 diabetes, MS, lupus as autoimmuneHLM10
C3.1.2 The kidney regulates blood osmolarity and composition through filtration, selective reabsorption and secretion in the nephron.Glomerulus (ultrafiltration); proximal tubule, loop of Henle, DCT, collecting duct; ADH controls water reabsorption; aldosterone controls Na⁺ SLM10
C3.1.3 Endotherms regulate body temperature using metabolic heat and behavioural responses; ectotherms rely mainly on external sources.Hypothalamus as thermostat; shivering (heat generation); sweating/panting (cooling); vasoconstriction/dilation; countercurrent exchange SLM10
C4Ecosystems — Populations, Energy & Matter
C4.1.1Population growth follows exponential (J-shaped) or logistic (S-shaped) patterns depending on limiting factors.Biotic potential; carrying capacity K; density-dependent limiting factors; predator-prey oscillationsSLM11
C4.1.2Species interact through competition, predation, mutualism, parasitism and commensalism.Gause's competitive exclusion; apparent competition; cleaning stations; mycorrhizae; host specificity of parasitesSLM11
C4.1.3Mark-recapture (Lincoln-Petersen) method estimates population size; assumptions must be stated and evaluated.N = (M × n)/R; assumptions: closed population, random mixing, marks don't affect survival or behaviourHLM11
C4.2.1Energy flows through ecosystems as trophic levels, with ~10% transferred between levels; nutrients cycle continuously.Producers → primary → secondary consumers; heat loss at each level; NPP; carbon and nitrogen cyclesSLM11
C4.2.2Nitrogen cycles through ecosystems via fixation, nitrification, assimilation, ammonification and denitrification.Rhizobium (root nodules); Nitrosomonas, Nitrobacter; Pseudomonas denitrifiers; industrial fixation (Haber)SLM11
C4.2.3 Ecological pyramids of energy, biomass and numbers quantify the structure of communities; energy pyramids are always pyramid-shaped.GPP vs. NPP; energy lost as heat at each level; detritivores and decomposers; inverted biomass pyramids (marine) SLM11
Theme D Continuity and Change
D1Molecules — Replication, Protein Synthesis & Gene Editing
D1.1.1DNA replication is semi-conservative; new strands are synthesised by DNA polymerase in the 5'→3' direction.Helicase unwinds; primase adds primer; leading strand continuous; lagging strand (Okazaki fragments); ligase joinsSLM7
D1.2.1Transcription produces mRNA from a DNA template; in eukaryotes, pre-mRNA is processed before translation.RNA polymerase; promoter binding; terminator; 5' cap, poly-A tail; splicing (introns removed, exons joined)SLM7
D1.2.2Translation converts mRNA codons into amino acid sequences at ribosomes using tRNA anticodons.Start codon AUG; A, P, E sites; peptide bond formation; stop codons; polyribosomes; signal peptideSLM7
D1.3.1Mutations are heritable changes in DNA sequence; their effects depend on type and location.Silent (same AA), missense (different AA), nonsense (stop codon); frameshift (insertion/deletion); sickle cell exampleSLM7
D1.3.2CRISPR-Cas9 is a gene-editing tool that uses a guide RNA to direct Cas9 to make precise DNA cuts.Guide RNA (gRNA) complementary to target; Cas9 nuclease; NHEJ (knockout) vs. HDR (replacement); applicationsSLM7
D1.3.3Somatic gene editing affects only the individual; germline editing has heritable consequences and raises ethical concerns.He Jiankui 2018; off-target effects; mosaic mutations; international moratorium on clinical germline editingHLM7
D1.2.3 The genetic code is a triplet, non-overlapping, degenerate and (almost) universal code; degeneracy reduces the effect of silent mutations.64 codons for 20 amino acids; 3 stop codons; AUG start; wobble position; near-universal evidence for common ancestry SLM7
D1.1.2 DNA polymerase has proofreading activity that corrects errors during replication, maintaining high fidelity.3'→5' exonuclease activity; error rate ~1 in 10⁹ after repair; mismatch repair; nucleotide excision repair; cancer connection SLM7
D2Cells — Division, Gene Expression & Water Potential
D2.1.1Mitosis produces two genetically identical daughter cells; the cell cycle is regulated by cyclins and CDKs.Interphase (G1, S, G2); PMAT phases (Prophase, Metaphase, Anaphase, Telophase); spindle fibres; cleavage furrow; cyclin-CDK checkpoints (G1, G2, M)SLM4
D2.1.2Meiosis produces four haploid cells; crossing over and independent assortment generate genetic variation.Meiosis I: homologous separation; Meiosis II: sister chromatid separation; chiasmata; 2ⁿ combinations (n=23 → 8 million)SLM4
D2.2.1Gene expression is regulated at transcriptional level by transcription factors binding to promoter and enhancer regions.Activators, repressors; hormone response elements; combinatorial control; TATA box; RNA polymerase IIHLM7
D2.2.2Epigenetic modifications (DNA methylation, histone modification) alter gene expression without changing DNA sequence; some are heritable.CpG methylation → gene silencing; histone acetylation → open chromatin (active); deacetylation → closed; cancer epigeneticsHLM7
D2.2.3RNA interference (RNAi) silences genes post-transcriptionally via siRNA or miRNA.DICER processes dsRNA → siRNA; RISC complex; mRNA cleavage or translational repression; therapeutic applicationsHLM7
D2.3.1Water potential (Ψ) is the tendency of water to move; Ψ = Ψ_s + Ψ_p; water moves from high to low Ψ.Solute potential Ψ_s (always negative); pressure potential Ψ_p; turgor (Ψ_p positive in turgid cells); osmometrySLM3
D2.3.2Plant cells respond to changes in external solute concentration through turgor changes; plasmolysis occurs in hypertonic solutions.Incipient plasmolysis: Ψ_p = 0; fully turgid: Ψ = 0 (if in pure water); osmotic concentration of tissue from graphSLM3
D3Organisms — Reproduction, Inheritance & Homeostasis
D3.1.1Sexual reproduction involves gametogenesis and fertilisation; the menstrual cycle is regulated by hormones.Oogenesis vs. spermatogenesis; FSH (follicle) → oestrogen → LH surge → ovulation → progesterone; IVFSLM10
D3.2.1Inheritance follows Mendel's laws of segregation and independent assortment; deviations occur through linkage and crossing over.Monohybrid and dihybrid crosses; test cross; codominance; sex-linkage; chi-squared test to test ratiosSLM7
D3.2.2Hardy-Weinberg equilibrium describes stable allele frequencies in large, non-evolving populations.p + q = 1; p² + 2pq + q² = 1; five conditions; deviation indicates evolution; calculate from phenotype frequencySLM8
D3.3.1Homeostasis maintains internal conditions within narrow limits through negative feedback involving sensors, control centres and effectors.Temperature (hypothalamus); blood glucose (pancreas); kidney (ADH, aldosterone); osmoregulation in marine/freshwater fishSLM10
D3.3.2 Diabetes mellitus results from failure of blood glucose homeostasis; Type 1 (no insulin) differs from Type 2 (insulin resistance).Type 1: autoimmune destruction of β-cells; Type 2: lifestyle-associated receptor desensitisation; glucose tolerance test; treatments SLM10
D3.2.3 Sex-linked genes are located on the X chromosome; males (XY) are hemizygous and express recessive alleles more often.Colour blindness, haemophilia, Duchenne muscular dystrophy; pedigree analysis; carrier females; X-inactivation (Lyon hypothesis) SLM7
D3.1.2 Plants reproduce sexually via pollination and fertilisation, producing seeds dispersed by various mechanisms.Stamen (pollen), pistil (ovule); self- vs. cross-pollination; double fertilisation in angiosperms; seed and fruit dispersal adaptations SLM4
D4Ecosystems — Selection, Stability & Climate
D4.1.1Natural selection can be directional, stabilising or disruptive depending on the fitness landscape.Directional: antibiotic resistance; stabilising: human birth weight; disruptive: beak size (character displacement)SLM8
D4.1.2 Genetic drift causes random changes in allele frequencies, especially in small populations (bottleneck, founder effect).Cheetah bottleneck; Amish Ellis-van Creveld; drift vs. selection; effective population sizeSLM8
D4.2.1Ecosystem stability depends on species diversity, food web complexity and keystone species.Resistance (withstand disturbance); resilience (recover); keystone species (wolves in Yellowstone); trophic cascadesSLM11
D4.3.1Enhanced greenhouse effect caused by increased CO₂, CH₄ and N₂O is driving global temperature rise.IPCC evidence; ice cores; 1.1°C rise since 1850; feedback loops (permafrost, albedo); attribution scienceSLM11
D4.3.2Ocean acidification results from CO₂ dissolving in seawater, threatening calcifying organisms.CO₂ + H₂O → H₂CO₃ → H⁺ + HCO₃⁻; pH has fallen 0.1 units (30% more acidic); coral bleaching; pteropodsSLM11
D4.3.3Climate change drives phenological shifts, range shifts and increased extinction risk for many species.Cherry blossom dates; poleward/upslope migration; mismatch between species interdependencies; IUCN projectionsSLM11
D4.2.2 Ecological succession is the directional change in community composition over time, from pioneer species to a climax community.Primary (bare rock/sand) vs. secondary (after disturbance); facilitation model; inhibition model; disclimax; fire ecology SLM11
D4.1.3 Sexual selection is driven by competition for mates and mate choice; it can produce traits that reduce survival fitness.Intersexual (female choice: peacock tail); intrasexual (male-male competition: deer antlers); runaway selection; honest signalling SLM8