DP Biology Guide Notes (First assessment 2025)
Diploma Programme Biology guide – Comprehensive study notes (First assessment 2025)
Purpose of the document
Guide for planning, teaching and assessment of Biology in the Diploma Programme (DP).
Primary audience: subject teachers; also informs students and parents about the subject.
Resources available via the IB Programme Resource Centre and IB Store.
IB mission and learner profile (context for DP)
IB mission: develop inquiring, knowledgeable and caring young people who help create a better, more peaceful world through intercultural understanding and respect.
Learner profile (10 attributes) – represented in practice across the DP:
Inquirer, Knowledgeable, Thinker, Communicator, Principled, Open-minded, Caring, Risk-taker, Balanced, Reflective.
The DP aims to cultivate internationally minded people who recognize shared humanity and guardianship of the planet.
Nature of Science (NOS) – overarching theme in DP sciences
Key ideas: purpose, features and impact of scientific knowledge; science as a communal, peer-reviewed enterprise.
Aspects of NOS (highlights):
Observations, Patterns, Hypotheses, Experiments, Measurement, Models, Evidence, Theories, Falsification, Shared endeavour, Global impact.
How NOS links to other IB elements:
Distinction from Theory of Knowledge (TOK): NOS informs knowledge questions; TOK questions reliability, objectivity, and knowledge claims.
Implications: science must acknowledge assumptions, exceptions and limitations; avoid over-certainty; ethical and societal connections.
The DP structure and aims for Biology
DP is a two-year, pre-university program with a broad, coherent science education.
Six academic areas plus a central core:
Two modern languages (or one modern + one classical), a humanities/social science, an experimental science (Biology here), mathematics, and one of the creative arts.
Core DP elements (compulsory):
Theory of Knowledge (TOK): critical thinking about knowledge claims and knowledge construction.
Creativity, Activity, Service (CAS): personal development through a range of activities; fosters intercultural understanding and service.
Extended Essay (EE): 4,000-word independent research project (world studies EE available to combine two subjects).
Approaches to Teaching and Learning (ATL) across the DP:
Five ATL categories: thinking, social, communication, self-management, research.
Six approaches to teaching: inquiry-based, conceptually focused, contextualized, collaborative, differentiated, assessment-informed.
Academic integrity and attribution are central; candidates must acknowledge all sources and avoid plagiarism.
Approaches to learning (ATL) and pedagogy in Biology
ATL aims to develop affective, cognitive and metacognitive skills to support lifelong learning.
Relationship with IB learner profile attributes; ATL skills are integral across the DP, not limited to a single course.
Five skill categories (with examples):
Thinking: questioning, designing procedures, evaluating results, linking ideas, etc.
Communication: presentation of ideas, interpreting data, appropriate use of terminology.
Social: collaboration, conflict resolution, considering others’ perspectives.
Research: evaluating sources, academic integrity, use of standard referencing.
Self-management: goal setting, time management, feedback uptake.
Tools and inquiry: experimental techniques, technology use, mathematics; two inquiry processes (Exploring/designing; Collecting/processing data; Concluding/evaluating).
Conceptual approach in DP sciences:
Four themes guiding the syllabus: Unity and diversity; Form and function; Interaction and interdependence; Continuity and change.
Four levels of biological organization as conceptual lenses: Molecules, Cells, Organisms, Ecosystems.
Teaching in context and sensitive topics: engage with topical issues; acknowledge diverse personal values; provide guidance for sensitive topics.
Linking questions encourage networked knowledge across topics; teachers and students may create their own linking questions.
Assessment framework (DP Biology)
AOs (Assessment Objectives) reflect aims and the conceptual approach; four main objectives:
AO1: Demonstrate knowledge (terminology, facts, concepts; skills/methodologies).
AO2: Understand and apply knowledge (terminology, concepts; skills/methodologies).
AO3: Analyse, evaluate, and synthesize (procedures, data, trends, predictions).
AO4: Demonstrate the application of skills for ethical investigations.
Assessment components and approximate weighting (typical DP structure):
External assessment: Paper 1 (MCQ + data-based questions) and Paper 2 (data-based and extended-response).
Internal assessment (IA): Scientific investigation (research project) – assessed by teachers and moderated by IB. Weighting: 20% IA; 80% external.
SL vs HL differentiation (hours and content breadth/depth):
SL: 150 teaching hours; HL: 240 teaching hours; HL content is deeper and broader.
External assessment specifics (as outlined in DP Biology guidance):
Paper 1: MCQ + data-based questions; Paper 2: data-based and extended-response questions; calculators allowed.
HL papers include both standard and higher-level content; greater depth across topics.
IA specifics:
Single scientific investigation per student; 10 hours of classroom time recommended; maximum word count ~3000 words (not including charts, data tables, equations, etc.).
Four IA criteria: Research design, Data analysis, Conclusion, Evaluation; each criterion has level descriptors (0–6 for a total of 24 marks).
Best-fit approach for marking; emphasis on authenticity and independence; collaboration must be clearly delineated from collusion.
Syllabus architecture and connectivity
Four core themes (A–D) and four levels of organization (Molecules, Cells, Organisms, Ecosystems) structure the topics.
The syllabus contains detailed topic content (understandings) and guiding questions; includes NOS integration and the concept of linking questions between topics.
The syllabus roadmap provides a topic-by-topic outline with SL/HL content, recommended teaching hours, and examples of guiding questions, NOS links, and applications.
The guide emphasizes teaching biology in context: applications to real-world issues, global challenges, and ethical dimensions; connects to NOS and TOK ideas.
Syllabus content highlights by theme and topic (summary, paraphrased)
Theme A: Unity and diversity
A1.1 Water: water as the medium of life; hydrogen bonding; cohesion/adhesion; solvent properties; surface tension; buoyancy and heat properties.
A1.2 Nucleic acids: DNA/RNA structure, bases, backbone, replication, and gene expression basics; complementary base pairing; directionality (5'–3').
A2 Origins of cells: prebiotic conditions, origin of life hypotheses, evidence for LUCA, endosymbiosis; three domains; evolution of multicellularity; cell theory; viruses and their unique status.
A2.2 Cell structure: prokaryotes vs eukaryotes; organelles; microscopy; intracellular compartmentalization; cell division basics.
A2.3 Viruses: diversity and life cycles (lytic/lysogenic); origins of viruses; rapid evolution; role in biology.
A3 Diversity of organisms: variation within/between species; biological species concept; genome size variation; karyotyping; environmental DNA; whole-genome sequencing; extinction and speciation concepts.
A3.2 Classification and cladistics: taxonomy vs cladistics; molecular clocks; cladograms; phylogenetic relationships; domains vs kingdoms.
A4 Evolution and speciation: evidence for evolution; homologous/analogous structures; adaptive radiation; speciation mechanisms and reproductive isolation; conservation biology; EDGE prioritization; anthropogenic biodiversity crisis.
A4.2 Conservation of biodiversity: causes of biodiversity loss; conservation strategies (in situ, ex situ, rewilding, seed banks); human impact and ethical considerations.
Theme B: Form and function
B1 Carbohydrates and lipids: structure–function relationships; condensation/hydrolysis; monosaccharides; polysaccharides (starch/glycogen/cellulose); lipids (triglycerides, phospholipids); saturation and melting points; membrane lipids;
B1.2 Proteins: amino acids; peptide bonds; protein structure (primary, secondary, tertiary, quaternary); denaturation; protein–structure relationships; globular vs fibrous forms.
B2 Membranes and transport: phospholipid bilayer; membrane proteins; diffusion; osmosis; channels/pumps; membrane fluidity; cholesterol’s role; membrane trafficking; endo/exocytosis.
B2.1–B2.3 Organelles and compartmentalization; cell specialization: nucleus, mitochondria, chloroplasts, lysosomes, ER, Golgi; ribosomes; endosymbiotic origin; cell theory and organelle evolution; stem cells and differentiation.
B3 Gas exchange; B3.2 Transport; B3.3 Muscle and motility: gas exchange surfaces (lungs, leaves), circulatory transport, heart function, plant transport, muscle contraction models, neuromuscular junctions; energy and movement.
B4 Adaptation to environment; B4.2 Ecological niches: abiotic factors; biomes; adaptations to deserts, rainforests; predator–prey dynamics; competitive interactions; energy flow and nutrient cycling.
Theme C: Interaction and interdependence
C1 Enzymes and metabolism; C1.2 Cell respiration; C1.3 Photosynthesis: energy capture and currency (ATP); photophosphorylation; Calvin cycle; pigments and chromatography; photosystems; CO2 enrichment experiments.
C2 Chemical signaling; C2.2 Neural signaling: receptors, signal transduction, hormones, neurotransmitters; G-protein signaling; ion channels; synapses; action potentials; nociception and perception.
C3 Integration of body systems; C3.2 Defense against disease: pathogens, innate/adaptive immunity, B-lymphocytes, T-cells, antibodies, vaccination, herd immunity, HIV/AIDS, antibiotics and resistance.
C4 Populations and communities: ecological interactions (predation, herbivory, competition, mutualism); energy flow; ecological efficiency and production; keystone species; oceanic and terrestrial ecosystems; climate change implications.
Theme D: Continuity and change
D1 DNA replication; D1.3 Mutation and gene editing; D2 Cell and nuclear division (mitosis/meiosis, cancer risk); D2.2 Gene expression; D2.3 Water potential; D3 Reproduction, inheritance, homeostasis; D3.2 Inheritance; D3.3 Homeostasis; D4 Natural selection; D4.2 Stability and change; D4.3 Climate change.
Skills in the study of biology (key tools and processes)
Tools:
Tool 1: Experimental techniques (safety, measurement of mass/volume/time/temperature/length; observations).
Tool 2: Technology (sensors, data extraction from databases, modelling, image analysis).
Tool 3: Mathematics (arithmetic, algebra, units, significant figures, SI units, data interpretation, correlations, chi-squared, t-tests).
Inquiry processes (three inquiries):
Inquiry 1: Exploring and designing — formulating questions, hypotheses; designing valid methodologies; variable control.
Inquiry 2: Collecting and processing data — qualitative/quantitative data collection; data processing; identifying patterns.
Inquiry 3: Concluding and evaluating — interpreting data; drawing justified conclusions; evaluating uncertainties and proposing improvements.
Conceptual learning and linking questions:
Concept-based teaching; connections across topics; linking questions to build networked knowledge.
Teaching in local/global contexts; sensitivity to topical issues; integration with TOK and real-world applications.
Academic integrity and referencing
Candidates must acknowledge all sources; use a standard, consistent referencing style; audiovisuals cited as needed.
The IB does not prescribe a single reference style; minimum information includes author, date, title, and page numbers as applicable.
Plagiarism and collaboration rules governed by DP Academic integrity guidelines; checks include draft submissions and comparison of writing styles.
Assessment details (in more concrete terms)
External assessment (75–80% total; SL/HL differences):
Paper 1: MCQ and data-based questions; Paper 2: data-based and extended-response questions.
Calculators permitted; emphasis on AO1–AO3 objectives.
Internal assessment (IA) – Scientific Investigation (20%):
One individual investigation (or group with clearly defined individual component); up to 3000 words.
Four IA criteria with level descriptors: Research design, Data analysis, Conclusion, Evaluation (total 24 marks).
Best-fit marking, independent work, authenticity checks, and clear differentiation from collaboration.
HL vs SL: HL includes additional depth and breadth; SL has a standard set of core topics with fewer hours.
Command terms (brief reference): Define, Draw, List, Measure, State, Annotate, Calculate, etc. (used in exam questions and criterion descriptors).
Pedagogical connections: MYP and CP links
Biology at DP maintains continuity with MYP science education and the Career-related Programme (CP).
Emphasis on inquiry-based, contextualized learning; development of ATL skills supports transitions to tertiary education and future careers.
Practical implications for teachers and students
Plan for a global, collaborative learning environment; incorporate technologies, datasets, and simulations.
Use real-world contexts to illustrate NOS aspects; assess using the DP assessment criteria and ensure alignment with the aims.
Encourage students to build networked knowledge via linking questions across topics and to reflect on learning strategies.
Quick-reference equations and concepts (selected examples)
Population genetics (illustrative; not all content listed in detail here):
Hardy–Weinberg principle: if applicable, allele frequencies p and q satisfy p + q = 1 and genotype frequencies p^2 + 2pq + q^2 = 1.
Water potential in plant cells (D2.3):
Water potential is the sum of solute potential and pressure potential: ext{ψ}w = ext{ψ}s + ext{ψ}_p
NOS-related considerations include the role of falsifiability, peer review and the societal impact of scientific knowledge.
Final notes for exam preparation
Understand the four DP themes and how NOS runs through Biology content.
Be able to explain linking concepts across topics into networked knowledge.
Practice with Paper 1 and Paper 2 styles, including data-based questions and extended-response items.
Prepare for the IA by planning a robust, authentic experimental investigation with clear data analysis and reflection.
Remember to cite sources properly and discuss ethical considerations and limitations of methods.
Useful cross-cutting connections
NOS informs how we evaluate evidence in biology (e.g., data quality, peer review, limitations).
TOK connections: linking knowledge questions to biological content (e.g., role of technology in evidence generation, ethics in genetics).
Real-world relevance: climate change, biodiversity loss, food security, public health (vaccination, antibiotic resistance), and biotechnology applications.
Appendices and resources (as per guide)
Glossary of command terms; bibliography; references to Programme Resource Centre and IB Store.
The guide also includes recommended topics for the Collaborative Sciences Project and guidance on ethical considerations.
Quick reminders for study sessions
Keep a conceptual map of themes A–D and levels of organization; link related topics with linking questions.
Reinforce understanding of core biology concepts (cell structure, gene expression, metabolism, respiration, photosynthesis).
Practice interpreting graphs, data tables, and experimental results; emphasize uncertainties and error analyses.
Build fluency in scientific vocabulary and standard notation (LaTeX-friendly for equations): use … for mathematical expressions.
If you want, I can reorganize these notes into a topic-by-topic cheat-sheet or tailor a condensed revision checklist for your upcoming exam. You can also specify which sections you’d like expanded with more details or worked examples (e.g., extended essays topics, IA planning templates, or sample data-sets for practice questions).