CBSE Class 12 Biology Formulas and Key Equations
Key formulas, equations, and numerical values for CBSE Class 12 Biology board exam 2026. Genetics ratios, ecological formulas, and important biological values.
Biology is concept-heavy, but there are key formulas, ratios, and numerical values you must know for the CBSE Class 12 board exam. Here is your complete reference.
Genetics Formulas and Ratios
- Monohybrid cross ratio — 3:1 (phenotypic), 1:2:1 (genotypic).
- Dihybrid cross ratio — 9:3:3:1 (phenotypic).
- Test cross ratio — 1:1 for heterozygous parent.
- Hardy-Weinberg equation — p² + 2pq + q² = 1.
Ecology Formulas
- Net Primary Productivity — NPP = GPP - Respiration.
- Energy flow — 10% law (Lindeman's efficiency).
- Population growth — dN/dt = rN (exponential) or dN/dt = rN(K-N)/K (logistic).
- Species-area relationship — log S = log C + Z log A.
Key Numerical Values
- Human genome — approximately 3.3 billion base pairs.
- Number of chromosomes — 46 (23 pairs) in humans.
- Blood groups — A, B, AB, O (ABO system) + Rh factor.
- Normal body temperature — 37°C / 98.6°F.
Practise Biology concepts
Super Tutor has chapter-wise Biology practice for CBSE Class 12 with visual explanations.
Start Biology Practice — FreeFormulas based on CBSE Class 12 Biology syllabus 2026. Last updated: February 2026.
Turn this into board-exam marks
Super Tutor gives you chapter summaries, previous-year questions, and full mock exams matched to your board syllabus — so you revise smarter, not longer.
Start preparing — freeFrequently Asked Questions
Does Biology have many formulas?
Biology has fewer formulas than Physics or Chemistry, but key genetic ratios, ecological equations, and physiological values are frequently tested.
How to remember Biology formulas?
Use visual aids — draw Punnett squares for genetics, flowcharts for ecology. Practice numerical problems to reinforce the formulas.