Required Biology Practicals
Goal: Use a light microscope to observe plant/animal cells.
Key Steps: Peel onion epidermis → stain with Iodine → place coverslip at angle (avoid bubbles).
Formula: $Magnification = \frac{Image Size}{Actual Size}$
Common Error: Fingerprints on lens; focusing too fast (cracking slide).
Goal: Investigate range of sugar concentrations on tissue mass.
Method: Cut potato cylinders (same cork borer) → weigh initial mass → leave in solutions → dry gently → weigh final mass.
Result: % Change = $\frac{End - Start}{Start} \times 100$. If mass stays same, that's the isotonic point.
Goal: Effect of pH on Amylase breakdown of starch.
Test: Iodine test (Blue-Black = Starch present; Orange = Starch gone).
Control: Temperature (use water bath at 35°C).
Result: Fastest time to turn orange = Optimum pH.
Goal: Effect of light intensity on rate of photosynthesis.
Method: Count bubbles per minute or measure volume of $O_2$ produced.
Law: Inverse Square Law ($Intensity \propto \frac{1}{d^2}$).
Control: Use LED bulb (less heat) or beaker of water as heat sink.
Required Chemistry Practicals
Goal: Determine concentration of acid/alkali.
Method: Pipette alkali into flask → add indicator (Phenolphthalein/Methyl Orange) → add acid from Burette drop-wise near end.
Key: Read meniscus at eye level. Repeat until concordant results (within 0.10 $cm^3$).
Goal: Electrolysis of aqueous solutions (e.g., Copper Sulfate).
Rules: Cathode (-): Metal forms (unless more reactive than H, then Hydrogen). Anode (+): Halogen forms (unless no halide, then Oxygen).
Test: $O_2$ relights glowing splint; $H_2$ squeaky pop; $Cl_2$ bleaches litmus paper.
Goal: Effect of concentration, surface area, or temp.
Methods: 1. Disappearing Cross (precipitate turbidity). 2. Gas Collection (inverted measuring cylinder).
Analysis: Gradient of tangent on curve = Rate at that time.
Goal: Separate dyes in ink.
Calculation: $R_f = \frac{Distance \ moved \ by \ substance}{Distance \ moved \ by \ solvent}$
Critical: Pencil line (ink runs); solvent below line.
Required Physics Practicals
Goal: Determine SHC of a metal block.
Formula: $\Delta E = m c \Delta \theta$
Setup: Heater, Voltmeter (parallel), Ammeter (series), Thermometer, Stopclock.
Error: Heat loss to surroundings (wrap block in insulation).
Goal: Plot I-V graphs for Resistor, Filament Lamp, Diode.
Resistor: Straight line through origin (Ohmic).
Lamp: S-curve (Resistance increases as temp increases).
Diode: Flat then sharp rise (allows current one way only).
Goal: Determine density of irregular object.
Method: Weigh object ($m$). Use Eureka can (displacement can) to find volume ($V$) of water displaced.
Formula: $\rho = \frac{m}{V}$
IB Internal Assessment (IA) Decoder
Biology: Microscopy, Osmosis, Enzymes, Separation of pigments, Mesocosms, Ventilation, Transpiration.
Chemistry: Molar Mass of Gas, Titration standard, Calorimetry (Hess Law), Rates, Voltametric cells, Organic models.
Physics: g (freefall), Refractive Index, Internal Resistance, Young's Modulus.
- Personal Engagement: Why do YOU care? Make it unique.
- Exploration: Research Question, Variables, Safety.
- Analysis: Error bars, Uncertainties, $R^2$ values.
- Evaluation: Systematic vs Random errors. Realistic improvements.
- Communication: Clear terminology, sig figs, formatting.