FSc Biology Formulas
All FSc Biology formulas, chapter by chapter, with search and a printable layout.
This page covers both years of FSc/ICS. The formulas are listed by chapter and are not split into Part-I and Part-II.
Genetics (24)
| Formula | Expression |
|---|---|
| Hardy-Weinberg | p² + 2pq + q² = 1 |
| Allele Frequency | p + q = 1 |
| Dihybrid Ratio | 9:3:3:1 |
| Recombination Frequency | RF = recombinants/total × 100 |
| Monohybrid Ratio | 3:1 (phenotype) |
| Chi-Square Test (genetics) | χ² = Σ(O−E)²/E |
| Genetic Map Distance | 1 map unit = 1% recombination |
| Test Cross Ratio | 1:1 (heterozygous × homozygous recessive) |
| Trihybrid Ratio | 27:9:9:9:3:3:3:1 |
| Genetic Variance Components | Vp = Vg + Ve |
| Back Cross | offspring crossed with either parent genotype |
| Number of Gametes | 2ⁿ (n = number of heterozygous pairs) |
| Number of Genotype Combinations | 3ⁿ (n = number of gene pairs) |
| Linkage Group Number | linkage groups = haploid chromosome number |
| Multiple Alleles Genotypes | possible genotypes = C(n,2) + n, for n alleles |
| Epistasis Ratio (Dominant) | 12:3:1 |
| Epistasis Ratio (Recessive) | 9:3:4 |
| Complementary Gene Ratio | 9:7 |
| Lethal Gene Ratio | 2:1 |
| Polygenic Inheritance Classes | 2n+1 phenotype classes for n gene pairs |
| 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 |
Ecology (24)
| Formula | Expression |
|---|---|
| Exponential Growth | dN/dt = rN |
| Logistic Growth | dN/dt = rN(1 - N/K) |
| Growth Rate | r = (births - deaths)/N |
| Carrying Capacity Equation | dN/dt = rN(K−N)/K |
| Species Diversity (Shannon) | H' = −Σpᵢ ln(pᵢ) |
| Ecological Efficiency | EE = (energy at trophic n+1/energy at n) × 100 |
| Population Density | D = N/A |
| Birth Rate | b = births/(N × time) |
| Death Rate | d = deaths/(N × time) |
| Biomagnification (concept) | toxin concentration increases up trophic levels |
| Trophic Level Energy Loss | ~90% energy lost per trophic level |
| Net Primary Productivity | NPP = GPP − R |
| Trophic Level Efficiency | TLE = (production at n+1/production at n) × 100 |
| Simpson's Diversity Index | D = 1 − Σ(n/N)² |
| Species Richness | S = number of species in a community |
| Per Capita Growth Rate | r = b − d |
| Simpson's Index of Dominance | D = Σ(n/N)² |
| Species Evenness | E = H'/ln(S) |
| Biomass Pyramid (concept) | total biomass decreases at each higher trophic level |
| Gross Primary Productivity | GPP = NPP + R |
| 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 |
Physiology (24)
| Formula | Expression |
|---|---|
| Cardiac Output | CO = HR × SV |
| BMI | BMI = weight(kg)/height(m)² |
| Mean Arterial Pressure | MAP = DP + ⅓(SP - DP) |
| Osmosis Water Potential | Ψ = Ψs + Ψp |
| Vital Capacity | VC = TV + IRV + ERV |
| Glomerular Filtration Rate | GFR = Uᵢₙ × V / Pᵢₙ |
| Pulse Pressure | PP = SP − DP |
| Stroke Volume | SV = EDV − ESV |
| Respiratory Quotient | RQ = CO₂ produced/O₂ consumed |
| Renal Clearance | C = (U×V)/P |
| Blood Pressure Notation | BP = Systolic/Diastolic mmHg |
| Cardiac Cycle Duration | ≈0.8 s at 75 bpm |
| Total Peripheral Resistance | TPR = MAP/CO |
| Ejection Fraction | EF = (SV/EDV) × 100 |
| Tidal Volume Ventilation | Minute Ventilation = TV × RR |
| Alveolar Ventilation | VA = (TV − Dead Space) × RR |
| Body Surface Area (Du Bois) | BSA = 0.007184 × W^0.425 × H^0.725 |
| Oxygen Consumption | VO₂ = CO × (CaO₂ − CvO₂) |
| Poiseuille's Law (blood flow) | Q = πPr⁴/8ηL |
| Heart Rate Reserve | HRR = HRmax − HRrest |
| Maximum Heart Rate (estimate) | HRmax = 220 − age |
| Frank-Starling Law (concept) | stroke volume increases with venous return |
| Oxygen Saturation (concept) | percentage of hemoglobin bound with O₂ |
| Peak Expiratory Flow (concept) | maximum airflow rate during forced exhalation |
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 |
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 |
Immunology (2)
| Formula | Expression |
|---|---|
| Antibody Structure (concept) | Y-shaped protein with 2 heavy and 2 light chains |
| Primary vs Secondary Immune Response (concept) | secondary response is faster and stronger due to memory cells |
Microbiology (2)
| Formula | Expression |
|---|---|
| Binary Fission (concept) | asexual reproduction where a bacterial cell divides into two identical cells |
| Gram Staining (concept) | differentiates bacteria based on cell wall peptidoglycan content |
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 |
Human Anatomy & Physiology (12)
| Formula | Expression |
|---|---|
| Body Mass Index (BMI) | BMI = Weight (kg)/Height² (m²) |
| Basal Metabolic Rate (BMR) (concept) | the amount of energy the body needs at complete rest to maintain vital functions |
| Cardiac Output | CO = Heart Rate × Stroke Volume |
| Blood Pressure (concept) | expressed as Systolic/Diastolic pressure, e.g. 120/80 mmHg |
| Mean Arterial Pressure (MAP) | MAP = Diastolic Pressure + 1/3(Systolic − Diastolic) |
| Vital Capacity (Lungs) | VC = Tidal Volume + Inspiratory Reserve Volume + Expiratory Reserve Volume |
| Glomerular Filtration Rate (GFR) (concept) | the rate at which the kidneys filter blood, used to assess kidney function |
| Homeostasis (concept) | the body's ability to maintain a stable internal environment despite external changes |
| Reflex Arc Pathway (concept) | the neural pathway of a reflex: receptor → sensory neuron → spinal cord → motor neuron → effector |
| Action Potential (concept) | a rapid, temporary reversal of membrane potential that transmits a nerve impulse along an axon |
| Resting Membrane Potential | approximately −70 mV in most neurons, maintained by ion gradients across the membrane |
| Synapse (concept) | the junction where a neuron transmits an electrical or chemical signal to another cell |
Botany / Plant Physiology (12)
| Formula | Expression |
|---|---|
| Photosynthesis Overall Equation | 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂ |
| Cellular Respiration Overall Equation | C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (ATP) |
| Transpiration Rate (concept) | the rate of water vapor loss from a plant's leaves, mainly through stomata |
| Water Potential | Ψ = Ψs + Ψp, Ψs = solute potential, Ψp = pressure potential |
| Osmosis (concept) | movement of water across a semipermeable membrane from a region of high to low water potential |
| Stomatal Conductance (concept) | measures how easily gases (CO₂, water vapor) pass through the stomata |
| Photosynthetic Rate (concept) | the amount of CO₂ fixed or O₂ released by a plant per unit time |
| Compensation Point (concept) | the light intensity at which photosynthesis rate equals respiration rate, with no net gas exchange |
| Phototropism (concept) | directional growth of a plant in response to a light source, driven by auxin distribution |
| Geotropism / Gravitropism (concept) | directional growth response of a plant to gravity |
| Germination Percentage | Germination % = (Number of Seeds Germinated/Total Seeds Sown) × 100 |
| Leaf Area Index (LAI) | LAI = Total Leaf Area/Ground Area Covered |
Zoology / Animal Physiology (10)
| Formula | Expression |
|---|---|
| Metabolic Rate vs Body Size (concept) | larger animals generally have a lower metabolic rate per unit body mass than smaller animals |
| Kleiber's Law | Metabolic Rate ∝ Body Mass^(3/4) |
| Countercurrent Exchange (concept) | blood and water/air flow in opposite directions to maximize gas or heat exchange efficiency (e.g. fish gills) |
| Osmoregulation (concept) | the regulation of water and solute balance within an organism's body fluids |
| Ectotherm vs Endotherm (concept) | ectotherms rely on external heat sources to regulate body temperature; endotherms generate their own heat internally |
| Hemoglobin Oxygen Saturation (concept) | the percentage of hemoglobin binding sites occupied by oxygen, shown by the oxygen dissociation curve |
| Molting / Ecdysis (concept) | the periodic shedding of an exoskeleton to allow growth in arthropods |
| Metamorphosis (concept) | a biological transformation from a larval to an adult form, e.g. tadpole to frog |
| Peristalsis (concept) | wave-like muscle contractions that move food through the digestive tract |
| Digestive Efficiency | Digestive Efficiency = (Food Consumed − Feces Produced)/Food Consumed × 100 |
Reproductive Biology (8)
| Formula | Expression |
|---|---|
| Menstrual Cycle Length (concept) | typically about 28 days, divided into follicular, ovulation, and luteal phases |
| Gestation Period (concept) | the duration of pregnancy from fertilization to birth, about 38–40 weeks in humans |
| Fertilization (concept) | the fusion of a sperm cell and an egg cell to form a diploid zygote |
| Spermatogenesis vs Oogenesis (concept) | spermatogenesis produces four sperm cells; oogenesis produces one egg and polar bodies from one parent cell |
| Fecundity (concept) | the potential reproductive capacity of an organism, measured by the number of offspring produced |
| Sexual vs Asexual Reproduction (concept) | sexual reproduction combines genetic material from two parents; asexual reproduction produces genetically identical offspring from one parent |
| Hormonal Control of Ovulation (concept) | a surge in Luteinizing Hormone (LH) triggers the release of an egg from the ovary |
| Placenta Function (concept) | exchanges nutrients, gases, and waste between mother and fetus during pregnancy |
Histology (8)
| Formula | Expression |
|---|---|
| Types of Epithelial Tissue (concept) | squamous, cuboidal, and columnar, each occurring as simple (single layer) or stratified (multiple layers) |
| Connective Tissue (concept) | tissue that supports, binds, and protects other tissues and organs, e.g. bone, cartilage, blood |
| Muscle Tissue Types (concept) | skeletal (voluntary, striated), smooth (involuntary, non-striated), cardiac (involuntary, striated) |
| Nervous Tissue (concept) | tissue made of neurons and glial cells that generates and transmits electrical signals |
| Basement Membrane (concept) | a thin extracellular layer that separates epithelial tissue from the underlying connective tissue |
| H&E Staining (concept) | Hematoxylin stains cell nuclei blue/purple; Eosin stains cytoplasm and extracellular matrix pink |
| Tissue Section Thickness (Microtome) | typically 4–10 micrometers (µm) for standard light microscopy |
| Cell Density in Tissue | Cell Density = Number of Cells/Area or Volume of Tissue |
Embryology (8)
| Formula | Expression |
|---|---|
| Fertilization (concept) | the fusion of sperm and egg nuclei to form a diploid zygote |
| Cleavage (concept) | rapid mitotic division of the zygote into smaller cells without an overall increase in size |
| Blastula Stage (concept) | a hollow ball of cells formed after cleavage, enclosing a fluid-filled cavity called the blastocoel |
| Gastrulation (concept) | the process that forms the three germ layers: ectoderm, mesoderm, and endoderm |
| Germ Layer Derivatives (concept) | ectoderm → skin/nervous system, mesoderm → muscle/bone, endoderm → gut lining and associated organs |
| Neurulation (concept) | the formation of the neural tube from ectoderm, which later develops into the brain and spinal cord |
| Gestation Period (concept) | the time between fertilization and birth, which varies widely between species |
| Apgar Score (concept) | a quick newborn health assessment based on Appearance, Pulse, Grimace, Activity, and Respiration |
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 FSc Biology formulas are on this page?
155 formulas in 16 chapters.
Can I print the FSc Biology formulas?
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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.