📞+65 8870 1152

Combined Physics + Biology (N(A)): Master Your N Level Combined Science

By Sarah Goh, Combined Physics–Biology Tutor

Updated August 26, 2025 • N(A) Integration Guide • 16 min read

🧬 The Life–in–Motion Bridge

Combined Physics–Biology (Sec 4 N(A)) connects how forces and energy shape living systems. Learn to explain biological processes with physics ideas like pressure, heat transfer, waves and electricity — the exact integration examiners love in Combined Science.

Singapore students studying biomechanics, diffusion and thermoregulation for N Level Combined Physics-Biology

🎯 Why Physics + Biology (N(A))

Among Combined Science options, Physics–Biology suits students interested in healthcare, sports science, environmental technology, and public health. You will learn to analyse living functions using physics — from blood pressure and ventilation to plant transport and light in photosynthesis (core ideas remain within the N(A) Combined Science scope).

Pathways This Builds:

Healthcare support & nursing diplomas
Sports & exercise science foundations
Environmental health & vector control
Biomedical engineering basics
Food science & nutrition
Urban farming & plant systems

📚 Syllabus-Aligned Topics (Sec 4 N(A))

Physics Topics

  • Physical Quantities, Units and Measurement
  • Kinematics
  • Force and Pressure
  • Dynamics
  • Energy
  • Kinetic Particle Model of Matter
  • Thermal Processes
  • General Wave Properties
  • Electromagnetic Spectrum
  • Electric Charge and Current of Electricity
  • D.C. Circuits
  • Practical Electricity
  • Radioactivity

Biology Topics

  • Cell Structure and Organisation
  • Movement of Substances
  • Biological Molecules
  • Nutrition in Humans
  • Transport in Humans
  • Respiration in Humans
  • Infectious Diseases in Humans
  • Nutrition and Transport in Flowering Plants

Note: This page is written specifically for Combined Science, Sec 4 N(A), not the Express syllabus.

🧪 Assessment Overview & Study Rhythm

Paper Structure (Combined Science)

  • • Each discipline has an MCQ paper and a Structured paper.
  • • MCQ assesses definitions, recall and quick applications across all topics.
  • • Structured questions test explanations, data handling and practical understanding.

Tip: Follow your school’s latest schedule for timings/marks; practise a split of ~40% time for MCQ, ~60% for Structured within each session.

⏱️ Session Management (Suggested)

Order: Start with your stronger subject’s MCQ → switch to its Structured → move to the other subject’s MCQ → finish with Structured.

Checkpoints: Mark uncertain MCQs, return only if time allows. For Structured, write formula/definition first, then substitute values or key terms.

Calculator hygiene: For physics calculations, show units; for biology, define processes (e.g., diffusion/osmosis) before applying.

⚡ The Integration Advantage: Physics ⟷ Biology

High-scoring answers often link physics mechanisms to biological function. Use these N(A)-friendly pairings when explaining.

🔗 Core Integration Patterns

Force & Pressure ↔ Human Circulation

  • • Blood pressure relates to force/area and vessel diameter.
  • • Valves create one-way flow (pressure differences).
  • • Pulse/heart rate changes with activity (work & energy demand).

Kinetic Particle Model & Thermal ↔ Diffusion/Osmosis

  • • Higher temperature → faster particle motion → faster diffusion.
  • • Concentration gradients drive net movement across membranes.
  • • Osmosis explains water uptake in cells and plant roots.

Waves & EM Spectrum ↔ Vision & Photosynthesis

  • • Visible light wavelengths enable human vision and plant photosynthesis.
  • • UV hazards and protection (skin, eyes; sunscreen/glasses).
  • • X-rays in medical imaging (safety awareness only).

Electricity & Practical Electricity ↔ Medical Devices & Safety

  • • Electrical safety when using equipment (fuses, earthing, insulation).
  • • Sensors in thermometers/pulse oximeters relate current/voltage to readings.
  • • Simple circuits model how devices monitor body conditions.

Energy & Work ↔ Respiration

  • • Respiration provides energy for muscular work (mechanical energy).
  • • During activity, higher energy demand → increased breathing/heart rate.
  • • Energy conversions: chemical (glucose) → thermal + mechanical.

Radioactivity ↔ Medicine

  • • Tracer isotopes in diagnostics (conceptual awareness).
  • • Safety: exposure minimisation, shielding, distance, time.
  • • Distinguish contamination vs irradiation in healthcare contexts.

🇸🇬 Singapore Applications

Use local contexts to anchor explanations and raise evaluation marks.

🏥 Health & Public Safety

Hospital Imaging (SGH/NUH)

EM spectrum in X-ray/CT usage (concept level) + radiation safety protocols.

Heat & Hydration in PE Lessons

Thermal processes, evaporation and body temperature regulation.

Dengue Prevention (NEA)

Movement of substances in water storage, mosquito life cycle; community measures.

🌿 Environment & Food

Vertical Farms (e.g., Lim Chu Kang)

Light wavelength impacts on plant growth; transpiration and water transport.

MRT Ventilation & Crowd Heat

Airflow, convection and diffusion in enclosed spaces.

Food Labels & Nutrition

Biological molecules (carbs, fats, proteins) and energy values.

📈 Topic Mastery Map (N(A) Focus)

🧪 Biology Mastery Priorities

Foundation

  • • Cell structure & organelles
  • • Diffusion & osmosis definitions
  • • Biological molecules basics

Core Human

  • • Nutrition & enzymes
  • • Blood, heart & circulation
  • • Aerobic/anaerobic respiration

Plants & Health

  • • Plant transport & leaf adaptations
  • • Infectious disease transmission & control

⚙️ Physics Mastery Priorities

Mechanics

  • • Kinematics graphs & units
  • • Force, pressure & moments (concept)
  • • Work, power & energy

Matter & Thermal

  • • Kinetic particle model
  • • Conduction, convection, radiation

Waves & Electricity

  • • General wave properties & sound/light
  • • EM spectrum uses & hazards
  • • Current, voltage, resistance; simple DC circuits
  • • Practical electricity & safety
  • • Radioactivity (basic ideas & safety)

🎯 A1 Strategies for N(A) Combined Physics–Biology

🥇 Integration Method

  • Define → Link → Apply: Define the biology process (e.g., osmosis), link the physics driver (e.g., kinetic motion/pressure), then apply to the scenario.
  • Energy Flow Lens: Track energy form changes: chemical → mechanical/thermal in activities, or light → chemical in plants.
  • Diagram Discipline: For circuits and anatomy, label arrows/units; marks are awarded for accuracy.

🥈 Problem-Solving Framework (BIO-PHY)

Biology process first (name it clearly)

Identify the physics driver (force/pressure/heat/light/electricity)

Outline key variables (concentration, area, temperature, voltage)

Plan the steps (equation or sequence)

Hone the answer with units/keywords

Yield a final integrated conclusion

🥉 Exam Technique

  • • Aim ~1–1.5 min per MCQ; move on and revisit flagged items.
  • • For calculations: write formula, substitute numbers with units, show working.
  • • For biology explanations: use 2–3 linked sentences with the exact keyword (e.g., “net movement”, “partially permeable membrane”).
  • • Practicals: state sources of error and improvements tied to the correct physics or biology principle.

❓ Combined Physics–Biology (N(A)) FAQs

Q: Is this page meant for Sec 4 N(A) or Express?

Sec 4 N(A). Topic lists and strategies here are aligned to the N(A) Combined Science scope.

Q: How do I revise both subjects efficiently?

Do 70% single-subject practice to secure fundamentals, 30% integrated questions where you must link physics to biological function.

Q: What are common mistakes?

Missing units in physics, not naming the biology process, and vague keywords (e.g., saying 'movement' instead of 'diffusion' or 'osmosis').

Q: Do I need advanced formulas not on the sheet?

No. Stick to formulae provided/learned in class; show working and keep units consistent.

🚀 Your Physics–Biology Mastery Journey

By linking forces, energy and waves to living systems, you’ll write stronger, clearer answers. Practise with Singapore contexts and the BIO-PHY framework to consolidate both subjects together.

Next Steps

Build

  • • Secure definitions & units
  • • Master diffusion/osmosis vs active transport
  • • Practise circuits & graph questions
  • • Collect 10 local examples

Measure

  • • 80%+ on MCQ across topics
  • • Full working with correct units
  • • Biology answers with exact keywords
  • • Integrated explanations in 3–5 lines

🔬 Check out similar N-Level resources

Explore our curated guides to deepen your understanding and excel in your studies.

Ready to Excel in Combined Physics/Biology?

Connect with our specialized combined physics/biology tutors who make complex concepts clear and help you achieve your academic goals.

Request a Combined Physics/Biology Tutor

Free matching service • Combined Physics/Biology specialists • Proven grade improvements

WhatsApp Us