9th & 10th Class Biology Formulas
All 9th & 10th Class Biology formulas, chapter by chapter, with search and a printable layout.
Cell Biology (5)
| Formula | Expression |
|---|---|
| Magnification | M = Image size / Actual size |
| Surface Area of Sphere (cell) | SA = 4πr² |
| Volume of Sphere (cell) | V = (4/3)πr³ |
| Osmolarity | Osm = molarity × number of particles |
| Cell Cycle Duration (typical) | ~24 hours for a mammalian somatic cell |
Bioenergetics (4)
| Formula | Expression |
|---|---|
| Photosynthesis (word eq.) | 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ |
| Cellular Respiration | C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP |
| ATP Hydrolysis Energy | ATP → ADP + Pi + energy (~30.5 kJ/mol) |
| ATP Yield (Fermentation) | net 2 ATP per glucose |
Taxonomy (5)
| Formula | Expression |
|---|---|
| Binomial Nomenclature | Genus species (italicized) |
| Taxonomic Hierarchy | Kingdom>Phylum>Class>Order>Family>Genus>Species |
| Five Kingdom Classification | Monera, Protista, Fungi, Plantae, Animalia |
| Three Domain Classification | Bacteria, Archaea, Eukarya |
| Binomial Name Format | Genus (capitalized) + species (lowercase), italicized |
Basic Biology (27)
| Formula | Expression |
|---|---|
| Magnification Formula | M = size of image/size of object |
| Diffusion Rate | proportional to surface area, inversely to distance |
| Pulse Rate | beats per minute (bpm) |
| Vital Capacity (approx) | VC ≈ 4.8 L (average adult) |
| Water Potential (simplified) | Ψw = Ψs (solute potential, closed system) |
| Transpiration Rate | water loss (g) per unit time per unit leaf area |
| Turgor Pressure | Ψp = Ψw − Ψs |
| Resting Heart Rate (average) | ~72 beats per minute |
| Resting Breathing Rate (average) | ~12–16 breaths per minute |
| Blood Volume (approx) | ~7% of body weight |
| Red Blood Cell Lifespan | ~120 days |
| Cell Theory (concept) | all living things are made of cells, the basic unit of life |
| Homeostasis (concept) | maintenance of stable internal conditions despite external change |
| Photosynthesis Balanced Equation | 6CO2 + 6H2O + light -> C6H12O6 + 6O2 |
| Aerobic Respiration Balanced Equation | C6H12O6 + 6O2 -> 6CO2 + 6H2O + Energy |
| Anaerobic Respiration (Yeast) | C6H12O6 -> 2C2H5OH + 2CO2 + Energy |
| Lactic Acid Fermentation | C6H12O6 -> 2C3H6O3 + Energy |
| Osmosis (concept) | movement of water from high to low water potential across a semi-permeable membrane |
| Diffusion (concept) | net movement of particles from high to low concentration |
| Active Transport (concept) | movement of particles against a concentration gradient using ATP |
| Food Chain Energy Transfer Rule | about 10% of energy passes to the next trophic level |
| Enzyme Classification (concept) | oxidoreductases, transferases, hydrolases, lyases, isomerases, ligases |
| pH of Human Blood (normal range) | 7.35 - 7.45 |
| Normal Body Temperature | 37 degrees C (98.6 degrees F) |
| Menstrual Cycle Length (average) | 28 days |
| Human Chromosome Number | 46 (23 pairs) |
| Gestation Period (human, average) | ~280 days (40 weeks) |
Nutrition (7)
| Formula | Expression |
|---|---|
| Basal Metabolic Rate (approx) | BMR = 66 + 13.7W + 5H − 6.8A (men) |
| Caloric Value | Energy = mass × caloric value per g |
| Energy from Macronutrients | 4 kcal/g (carbs/protein), 9 kcal/g (fat) |
| Water Requirement (approx) | ≈35 mL/kg body weight/day |
| Protein Requirement (approx) | ~0.8 g/kg body weight/day |
| Body Water Content (approx) | ~60% of body weight |
| Glycemic Index (concept) | ranks carbohydrates by their effect on blood glucose |
Genetics (6)
| Formula | Expression |
|---|---|
| Monohybrid Ratio | 3:1 (phenotype) |
| Back Cross | offspring crossed with either parent genotype |
| Punnett Square Probability (Monohybrid) | 3:1 phenotypic ratio for heterozygous cross |
| Sex Determination (Humans) | XX = female, XY = male |
| Codominance (concept) | both alleles are fully and simultaneously expressed in heterozygote |
| Incomplete Dominance (concept) | heterozygote phenotype is a blend of both alleles |
Plant Biology (6)
| Formula | Expression |
|---|---|
| Transpiration Pull (concept) | water is pulled up the xylem due to evaporation from leaves |
| Translocation (concept) | movement of sugars through phloem from source to sink |
| Stomatal Opening (concept) | guard cells swell with turgor pressure to open the stomatal pore |
| Light Reaction (concept) | converts light energy to ATP and NADPH in the thylakoid membrane |
| Calvin Cycle (Dark Reaction, concept) | fixes CO2 into glucose using ATP and NADPH |
| Compensation Point (concept) | light intensity at which photosynthesis rate equals respiration rate |
Human Anatomy (4)
| Formula | Expression |
|---|---|
| Number of Bones (Adult Human) | 206 bones |
| Number of Vertebrae | 33 (in a child), 26 fused in an adult |
| Heart Chambers | 4 (2 atria, 2 ventricles) |
| Normal Resting Blood Pressure | ~120/80 mmHg |
Evolution (2)
| Formula | Expression |
|---|---|
| Natural Selection (concept) | organisms best adapted to their environment survive and reproduce more |
| Survival of the Fittest (concept) | individuals with favorable traits have a reproductive advantage |
Ecology (4)
| Formula | Expression |
|---|---|
| Food Web (concept) | interconnected network of multiple food chains in an ecosystem |
| Ecological Pyramid (concept) | graphical representation of energy, numbers, or biomass across trophic levels |
| Carbon Cycle (concept) | carbon moves between atmosphere, organisms, and geosphere via respiration, photosynthesis, decomposition |
| Nitrogen Fixation (concept) | conversion of atmospheric N2 into usable nitrogen compounds by bacteria |
More class-wise formulas
Formulas are for revision. Always follow the notation and rounding used in your own textbook and board papers.
FAQ
How many 9th & 10th Class Biology formulas are on this page?
70 formulas in 10 chapters.
Can I print the 9th & 10th Class Biology formulas?
Yes. Press Print / Save as PDF. The page switches to a clean black-on-white layout without menus.
How do I find one formula quickly?
Type a word such as velocity, area or mole in the search box. Only matching formulas stay visible.
Do the formulas follow my board syllabus?
They follow the usual school and intermediate syllabus, but chapter lists differ between boards. Check your own syllabus for what is included in your exam.