NEET Biology Key Facts & Formulas 2026
All 70+ important NEET Biology facts, values, and formulas organized chapter-wise — Human Physiology, Genetics, Ecology, Biotechnology. Each tagged by exam frequency.
Human Physiology — Circulation & Respiration
12 formulasCardiac Output
Must KnowCO = SV × HR ≈ 5 L/min
SV ≈ 70mL, HR ≈ 72/min
Vital Capacity
Must KnowVC = ERV + TV + IRV ≈ 4500 mL
Tidal Volume
Must KnowTV ≈ 500 mL per breath
Residual Volume
High FreqRV ≈ 1100–1200 mL
Total Lung Capacity
High FreqTLC = VC + RV ≈ 5700–6000 mL
Blood Composition
Must KnowPlasma 55% + Formed Elements 45%
RBC Count
Must KnowMales: 5–5.5 million/mm³; Females: 4.5–5 million/mm³
WBC Count
High Freq6000–8000/mm³
Platelet Count
High Freq1.5–3.5 lakhs/mm³
BP Normal
Must Know120/80 mmHg (systolic/diastolic)
Heart Sounds
High FreqLub (AV valves close); Dub (semilunar valves close)
Bohr Effect
Must KnowHigher CO₂/H⁺ → lower O₂ affinity of Hb
Human Physiology — Excretion & Digestion
8 formulasGFR
Must Know125 mL/min = 180 L/day
Urine Volume
Must Know≈ 1.5 L/day (99% reabsorbed)
pH of Blood
Must Know7.35–7.45
pH of Stomach
Must Know1.5–3.5 (HCl)
pH of Saliva
High Freq6.5–7.5
Dental Formula (Adult)
Must Know2123/2123 = 32 teeth
Small Intestine Length
High Freq≈ 6 meters (duodenum + jejunum + ileum)
Large Intestine Length
Medium≈ 1.5 meters
Genetics & Molecular Biology
12 formulasMonohybrid F2 Ratio
Must Know3:1 phenotypic, 1:2:1 genotypic
Dihybrid F2 Ratio
Must Know9:3:3:1 phenotypic
Test Cross
Must KnowDominant phenotype × homozygous recessive
Incomplete Dominance
Must Know1:2:1 phenotypic in F2
Codominance
Must Know1:2:1 with all 3 phenotypes expressed
e.g., ABO blood group
Hardy-Weinberg
Must Knowp² + 2pq + q² = 1; p + q = 1
Chargaff's Rule
Must KnowA = T, G = C; A+G = T+C (purines = pyrimidines)
Central Dogma
Must KnowDNA → RNA → Protein
Genetic Code
Must Know64 codons: 61 sense + 3 stop (UAA, UAG, UGA)
Start Codon
Must KnowAUG (Methionine)
DNA Replication
Must KnowSemi-conservative, 5' → 3' direction
Map Distance
High Freq1 cM = 1% recombination frequency
Ecology
10 formulas10% Energy Rule
Must KnowEach trophic level = 10% of previous
Logistic Growth
Must KnowdN/dt = rN(K−N)/K
K = carrying capacity
Exponential Growth
Must KnowdN/dt = rN → Nt = N₀eʳᵗ
Species-Area Relationship
Must Knowlog S = log C + Z·log A
Z = 0.1–0.2 (mainland), Z ≈ 0.6 (islands)
Shannon Diversity Index
Must KnowH' = −Σ(pᵢ × ln pᵢ)
Higher = more diverse
Net Primary Productivity
Must KnowNPP = GPP − Respiration
Birth Rate
High Freqb = B/N per capita
Death Rate
High Freqd = D/N per capita
Growth Rate
High Freqr = (b − d)
Species Richness
High FreqNumber of species in a community
Cell Biology
10 formulasCell Cycle Duration
Must KnowG1 + S + G2 + M ≈ 24 hrs (typical)
S Phase
Must KnowDNA replication: 2n → 4n DNA content
Mitosis Result
Must Know2n → 2n (2 identical cells)
Meiosis Result
Must Know2n → n (4 haploid cells)
ATP per Glucose (Aerobic)
Must Know36–38 ATP (theoretical max)
Glycolysis ATP
Must KnowNet 2 ATP + 2 NADH per glucose
In cytoplasm
Krebs Cycle
Must Know2 ATP + 6 NADH + 2 FADH₂ per glucose
In mitochondria
RQ (Carbohydrate)
High FreqRQ = CO₂/O₂ = 1.0
RQ (Fat)
High FreqRQ ≈ 0.7
Photosynthesis Equation
Must Know6CO₂ + 12H₂O → C₆H₁₂O₆ + 6O₂ + 6H₂O
Plant Physiology
6 formulasWater Potential
Must KnowΨ = Ψs + Ψp
Ψs = solute potential (always −ve)
Transpiration Pull
Must KnowMain force for water ascent in xylem
Photosynthesis (Light Reaction)
High Freq12H₂O + 12NADP⁺ → 12NADPH + 6O₂
In thylakoids
Calvin Cycle
Must Know3CO₂ → 1 G3P; 6 turns → 1 glucose
In stroma
C4 Pathway
Must KnowSpatial separation: mesophyll (PEP) + bundle sheath (RuBisCO)
Photorespiration
High FreqRuBisCO fixes O₂ instead of CO₂ → no ATP gain
Reproduction
6 formulasMenstrual Cycle
Must Know28 days: Follicular (1-13) + Ovulation (14) + Luteal (15-28)
Sperm Count (Normal)
High Freq≈ 200–300 million per ejaculate
Gestation Period
Must Know≈ 9 months (266 days / 38 weeks)
Embryo Implantation
High FreqDay 6-7 after fertilization (blastocyst stage)
hCG Detection
High FreqDetectable in urine by 2 weeks post-conception
Megasporogenesis
High Freq1 MMC → 4 megaspores → 1 functional
Biotechnology & Evolution
6 formulasPCR Steps
Must KnowDenaturation (94°C) → Annealing (55-65°C) → Extension (72°C)
Restriction Enzyme Cut
Must KnowPalindromic sequences (e.g., EcoRI: GAATTC)
Gel Electrophoresis
Must KnowSmaller fragments migrate faster → towards anode (+)
Age of Earth
High Freq≈ 4.5 billion years
Miller-Urey (Gases)
High FreqCH₄ + NH₃ + H₂ + H₂O → amino acids
Natural Selection Types
Must KnowStabilizing, Directional, Disruptive
Pro Tips from Top Scorers
Human Physiology carries ~20% marks — memorize all numerical values (CO, GFR, blood counts, pH values).
Genetics ratios (3:1, 9:3:3:1, 1:2:1) appear in almost every NEET paper — practice 50+ ratio problems.
Ecology formulas (logistic growth, Shannon index, species-area) are easy marks if you know them.
Create "NCERT sentence flashcards" — many NEET questions are direct NCERT sentences rephrased.
Practice labeling 20 key diagrams without looking: heart, nephron, neuron, flower, DNA, mitosis.
Formula Priority Breakdown
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