🚨 Emergency Revision
Revise everything in 3 hours. All 32 chapters condensed into ultra-dense summaries — your night-before-exam lifeline.
📚 32 chapters⏱ ~65 min✅ 0/32 reviewed🧬 24 Biology⚗️ 4 Chemistry⚛️ 4 Physics
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Biology
24 chapters0/24 done🧬 Biology
Human Physiology
⏱ ~2 min
- •Cardiac output = Stroke volume × Heart rate (≈5 L/min at rest)
- •SA node is the pacemaker of the heart, located in right atrium
- •Tidal volume is ~500 mL; vital capacity = TV + IRV + ERV (~3.5–4.5 L)
- •Residual volume (~1.2 L) is the air remaining after forceful expiration
- •Oxygen is transported mainly as oxyhaemoglobin (97%) and dissolved in plasma (3%)
- •CO₂ is transported as bicarbonates (70%), carbaminohaemoglobin (23%), and dissolved (7%)
- •Bohr effect: ↑CO₂/↑H⁺ shifts O₂-dissociation curve right → more O₂ release
- •GFR (Glomerular Filtration Rate) is ~125 mL/min or 180 L/day
- +12 more key facts
💡 Mnemonics
RAAS order: Renin → Angiotensinogen → Angiotensin I → (ACE) → Angiotensin II → Aldosterone
Digestive enzyme pH: Salivary amylase (6.8), Pepsin (1.5–2), Trypsin (8), Lipase (8)
ECG waves: P = atrial depolarization, QRS = ventricular depolarization, T = ventricular repolarization
Respiratory volumes: TV + IRV + ERV = Vital Capacity; VC + RV = Total Lung Capacity
🧬 Biology
Genetics & Evolution
⏱ ~2 min
- •Mendel's Law of Segregation: alleles separate during gamete formation
- •Law of Independent Assortment applies only to genes on different chromosomes
- •Crossing over occurs in pachytene stage of Prophase I of meiosis
- •Linkage was discovered by T.H. Morgan in Drosophila
- •Sex determination in humans: XX = female, XY = male; SRY gene on Y triggers maleness
- •Colour blindness and haemophilia are X-linked recessive disorders
- •Sickle cell anaemia: autosomal recessive, Glu → Val substitution in β-globin (GAG → GUG)
- •Hardy-Weinberg equation: p² + 2pq + q² = 1, where p + q = 1
- +12 more key facts
💡 Mnemonics
Chromosomal disorders: 'Down = 21 (D=Down, 21st chromosome)', 'Kline-XXY = extra X makes him XXY'
Prophase I stages: Leptotene, Zygotene, Pachytene, Diplotene, Diakinesis — 'Lazy Zebras Play During Dawn'
Hardy-Weinberg disturbance factors: 'MANGS' — Mutation, Assortative mating, Natural selection, Gene flow, Small population (drift)
Blood groups: IA IB = codominance; IA/IB over i = dominance
🧬 Biology
Cell Biology & Cell Division
⏱ ~2 min
- •Mitochondria and chloroplasts have their own circular DNA and 70S ribosomes
- •Ribosomes: 70S (prokaryotes, organelles) and 80S (eukaryotic cytoplasm)
- •Rough ER has ribosomes → protein synthesis; Smooth ER → lipid synthesis, detox
- •Golgi apparatus: cis face (forming/receiving) → trans face (maturing/shipping)
- •Lysosomes contain hydrolytic enzymes (acid hydrolases, pH ~5); 'suicide bags'
- •Cell wall: plants = cellulose, fungi = chitin, bacteria = peptidoglycan
- •Fluid mosaic model (Singer & Nicolson, 1972): lipid bilayer with floating proteins
- •Active transport requires ATP; moves against concentration gradient (e.g., Na⁺/K⁺ pump)
- +12 more key facts
💡 Mnemonics
Mitosis stages: PMAT — Prophase, Metaphase, Anaphase, Telophase
Meiosis I stages: 'LZPDD' for Prophase I substages (Leptotene, Zygotene, Pachytene, Diplotene, Diakinesis)
Cell organelles with DNA: 'MiCh' — Mitochondria, Chloroplast
Endomembrane system: ER → Golgi → Lysosomes → Plasma membrane (flow of membranes)
🧬 Biology
Plant Physiology
⏱ ~2 min
- •Photosynthesis: 6CO₂ + 12H₂O → C₆H₁₂O₆ + 6O₂ + 6H₂O (light energy)
- •Light reactions occur in thylakoid membranes; Calvin cycle in stroma
- •PS II (P680) → water splitting (photolysis); PS I (P700) → NADPH formation
- •Cyclic photophosphorylation: only PS I, produces ATP only, no NADPH, no O₂
- •C3 plants: first product is 3-PGA (3C); enzyme is RuBisCO
- •C4 plants: first product is OAA (4C); enzyme is PEP carboxylase (mesophyll cells)
- •Photorespiration occurs in C3 plants; RuBisCO fixes O₂ instead of CO₂ — wasteful
- •Transpiration pull (cohesion-tension theory) is the main force for water ascent
- +12 more key facts
💡 Mnemonics
Plant hormones: 'AACGE' — Auxin, ABA, Cytokinin, Gibberellin, Ethylene
Krebs cycle products per turn: '3N-1F-1G-2C' = 3 NADH, 1 FADH₂, 1 GTP, 2 CO₂
C3 vs C4: 'C3 = RuBisCO first, C4 = PEPcase first'
Photorespiration mnemonic: 'C3 plants WASTE carbon when RuBisCO grabs O₂'
ETC complexes: 'I, II, III, IV + ATP synthase (Complex V)'
🧬 Biology
Ecology & Environment
⏱ ~2 min
- •Ecological succession: primary (bare rock) → pioneer species (lichens) → climax community
- •Secondary succession: starts on previously colonized but disturbed area (faster)
- •10% energy transfer law: only 10% energy passes from one trophic level to the next
- •Pyramid of energy is always upright; pyramid of biomass can be inverted (aquatic)
- •Pyramid of numbers can be inverted (e.g., tree ecosystem: 1 tree → many insects)
- •Biodiversity hotspots: high endemism + significant habitat loss (e.g., Western Ghats)
- •Species-area relationship: log S = log C + Z log A (Z = 0.1–0.2 within continent)
- •r-selected species: small, many offspring, short-lived; K-selected: large, few offspring
- +12 more key facts
💡 Mnemonics
Population interactions: 'MuCoPaPr' — Mutualism (+/+), Commensalism (+/0), Parasitism (+/−), Predation (+/−), Competition (−/−)
Ecological succession: 'LiMoGrSh-Trees' — Lichens → Mosses → Grasses → Shrubs → Trees
Greenhouse gases: 'COM-N' — CO₂, O₃ (indirect), Methane, N₂O
Biodiversity levels: 'GSE' — Genetic, Species, Ecosystem diversity
🧬 Biology
Human Reproduction
⏱ ~2 min
- •Spermatogenesis: spermatogonia (2n) → primary spermatocyte → secondary → spermatids → sperm
- •Oogenesis begins in foetal life; primary oocytes arrested in Prophase I (diplotene)
- •Ovulation releases secondary oocyte (arrested in Metaphase II); completes meiosis II only if fertilized
- •Sperm structure: acrosome (enzymes for penetration), middle piece (mitochondria for energy), tail (motility)
- •Fertilization occurs in the ampullary-isthmic junction of the fallopian tube
- •Implantation occurs ~7 days after fertilization in the endometrium; blastocyst implants
- •hCG (human Chorionic Gonadotropin) is produced by trophoblast; basis of pregnancy tests
- •Placenta produces hCG, hPL, estrogen, progesterone, and relaxin
- +12 more key facts
💡 Mnemonics
Spermatogenesis: 'Sg → Sc1 → Sc2 → St → Sz' (Spermatogonia → Primary spermatocyte → Secondary → Spermatid → Spermatozoa)
Menstrual phase order: 'MFO-S' — Menstrual, Follicular, Ovulation, Secretory
Placental hormones: 'HEP-HR' — hCG, Estrogen, Progesterone, hPL, Relaxin
Umbilical cord: 'AVA' — Artery, Vein, Artery (2 arteries + 1 vein)
🧬 Biology
Biotechnology
⏱ ~2 min
- •Restriction enzymes cut DNA at specific palindromic sequences; produce sticky or blunt ends
- •EcoRI recognizes GAATTC and cuts between G and A — first RE widely used
- •DNA ligase joins DNA fragments (Okazaki fragments in replication, recombinant DNA in cloning)
- •Vectors: pBR322 (plasmid), λ phage, BAC, YAC; must have ori, selectable marker, cloning site
- •pBR322 has ampicillin resistance (ampR) and tetracycline resistance (tetR) genes
- •Insertional inactivation: foreign DNA inserted in antibiotic resistance gene → gene disrupted
- •PCR steps: Denaturation (94°C) → Annealing (50–65°C) → Extension (72°C, Taq polymerase)
- •Taq polymerase from Thermus aquaticus is thermostable — key to PCR automation
- +12 more key facts
💡 Mnemonics
PCR steps: 'DAE' — Denaturation, Annealing, Extension (repeat 30–40 cycles)
pBR322 markers: 'AT' — Ampicillin resistance, Tetracycline resistance
Bt toxin pathway: 'Pro-cry → Cry protein → Crystal → Gut alkaline → Active toxin → Pores → Death'
Cloning vector requirements: 'ORC' — Origin of replication, Restriction site, Clone selection marker
🧬 Biology
Diversity in Living World
⏱ ~2 min
- •Taxonomy is the science of identification, nomenclature, and classification of organisms
- •Binomial nomenclature was given by Carolus Linnaeus — genus + species (e.g., Homo sapiens)
- •Taxonomic hierarchy: Kingdom → Phylum → Class → Order → Family → Genus → Species
- •ICBN governs plant nomenclature; ICZN governs animal nomenclature
- •Species is the basic unit of classification — a group of organisms that can interbreed
- •Whittaker's Five Kingdom classification: Monera, Protista, Fungi, Plantae, Animalia
- •Monera: prokaryotic, unicellular (bacteria, cyanobacteria, mycoplasma)
- •Protista: unicellular eukaryotic (Amoeba, Paramecium, Euglena, diatoms, dinoflagellates)
- +10 more key facts
💡 Mnemonics
Taxonomic hierarchy: 'King Philip Came Over For Good Spaghetti' → Kingdom, Phylum, Class, Order, Family, Genus, Species
Five Kingdoms: 'My Pretty Fungi Plants Animals' → Monera, Protista, Fungi, Plantae, Animalia
Virus discoverer: Ivanowsky (TMV); crystal: Stanley; virus coined by Pasteur
Lichens types: 'CCF' — Crustose (flat), Corticolous (on bark), Foliose (leaf-like), Fruticose (shrub-like)
🧬 Biology
Structural Organisation in Animals & Plants
⏱ ~2 min
- •Simple tissues in plants: parenchyma (storage), collenchyma (flexibility), sclerenchyma (strength)
- •Complex tissues: xylem (tracheids, vessels, fibres, parenchyma) and phloem (sieve tubes, companion cells, fibres, parenchyma)
- •Meristematic tissues: apical (tips), lateral (cambium), intercalary (base of internodes)
- •Epithelial tissue: squamous, cuboidal, columnar, ciliated; can be simple or stratified
- •Connective tissue types: areolar, adipose, tendons (bone to muscle), ligaments (bone to bone), cartilage, bone, blood
- •Muscle types: skeletal (striated, voluntary), smooth (non-striated, involuntary), cardiac (striated, involuntary)
- •Nervous tissue: neurons (structural/functional unit) + neuroglia (support cells)
- •Earthworm: clitellum secretes cocoon; typhlosole increases intestinal absorption
- +8 more key facts
💡 Mnemonics
Xylem elements: 'TV FP' — Tracheids, Vessels, Fibres, Parenchyma
Phloem elements: 'SCFP' — Sieve tubes, Companion cells, Fibres, Parenchyma
Connective tissues: 'AATL CBB' — Areolar, Adipose, Tendon, Ligament, Cartilage, Bone, Blood
Muscle types: 'SSC' — Skeletal (striated, voluntary), Smooth (unstriated, involuntary), Cardiac (striated, involuntary)
🧬 Biology
Biomolecules
⏱ ~2 min
- •Carbohydrates: monosaccharides (glucose, fructose), disaccharides (sucrose, maltose, lactose), polysaccharides (starch, glycogen, cellulose)
- •Glucose is an aldohexose (C₆H₁₂O₆); fructose is a ketohexose
- •Proteins are polymers of amino acids joined by peptide bonds (–CO–NH–)
- •Primary structure: linear sequence of amino acids; secondary: α-helix and β-pleated sheet (H-bonds)
- •Tertiary structure: 3D folding (all bonds); quaternary: multiple polypeptide subunits (e.g., haemoglobin)
- •Enzymes are biological catalysts that lower activation energy; mostly proteins
- •Enzyme activity depends on temperature, pH, substrate concentration, and inhibitors
- •Competitive inhibition: inhibitor competes with substrate for active site; overcome by ↑[S]
- +10 more key facts
💡 Mnemonics
Essential amino acids: 'PVT TIM HALL' — Phe, Val, Thr, Trp, Ile, Met, His, Arg, Leu, Lys
Disaccharides: 'Sucrose = G+F, Maltose = G+G, Lactose = G+Gal' (G=glucose, F=fructose, Gal=galactose)
Enzyme classification: 'OTHLIL' — Oxidoreductases, Transferases, Hydrolases, Lyases, Isomerases, Ligases
Protein structure levels: '1-2-3-4: Sequence-Helix/Sheet-3Dfold-Subunits'
🧬 Biology
Animal Kingdom
⏱ ~2 min
- •Porifera: pore-bearing, diploblastic-like, cellular level organization; choanocytes line spongocoel
- •Cnidaria (Coelenterata): diploblastic, tissue level; cnidoblasts for defense; examples: Hydra, Jellyfish, corals
- •Platyhelminthes: flatworms, triploblastic, acoelomate, bilateral symmetry; e.g., Planaria, Taenia (tapeworm), Fasciola (liver fluke)
- •Aschelminthes (Nematoda): roundworms, pseudocoelomate; e.g., Ascaris, Wuchereria (elephantiasis)
- •Annelida: segmented worms, true coelom (schizocoelous), closed circulation; e.g., earthworm, leech, Nereis
- •Arthropoda: largest phylum, jointed appendages, chitinous exoskeleton, open circulation; e.g., insects, crabs, spiders
- •Mollusca: soft-bodied, mantle secretes shell, open circulation (except Cephalopoda); e.g., snail, octopus, pearl oyster
- •Echinodermata: spiny-skinned, water vascular system, radial symmetry in adults, bilateral in larvae; e.g., starfish, sea urchin
- +9 more key facts
💡 Mnemonics
Phyla order: 'Poor Creatures Prefer Arrangements of Nice Artistic Majestic Elegant Houses' → Porifera, Cnidaria, Platyhelminthes, Aschelminthes, Annelida, Arthropoda, Mollusca, Echinodermata, Hemichordata
Coelom types: 'AAP' — Acoelomate (Platyhelminthes), Pseudocoelomate (Aschelminthes), Coelomate (Annelida onward)
Chordata features: 'NDGP' — Notochord, Dorsal nerve cord, Gill slits, Post-anal tail
Mammalia subclasses: 'PMP' — Prototheria (egg-laying), Metatheria (marsupial), Eutheria (placental)
🧬 Biology
Plant Kingdom
⏱ ~2 min
- •Algae: chlorophyll-bearing, thalloid, autotrophic, aquatic; 3 classes by pigment
- •Chlorophyceae (green algae): chlorophyll a + b, starch storage; e.g., Chlamydomonas, Spirogyra, Ulva
- •Phaeophyceae (brown algae): chlorophyll a + c, fucoxanthin, laminarin/mannitol; e.g., Fucus, Laminaria, Sargassum
- •Rhodophyceae (red algae): chlorophyll a + d, phycoerythrin (red pigment); e.g., Polysiphonia, Gelidium (agar source)
- •Bryophytes: amphibians of plant kingdom; no vascular tissue; dominant gametophyte
- •Liverworts (Marchantia): thalloid, gemma cups for asexual reproduction
- •Mosses (Funaria): leafy gametophyte, protonema stage, sporophyte depends on gametophyte
- •Pteridophytes: first vascular plants; dominant sporophyte; e.g., Selaginella, Equisetum, Pteris
- +8 more key facts
💡 Mnemonics
Algae pigments: 'Green = a+b, Brown = a+c, Red = a+d' — ABC order matches pigment addition
Bryophyte progression: 'LHM' — Liverworts, Hornworts, Mosses
Gymnosperm examples: 'PCGS' — Pinus, Cycas, Ginkgo, Sequoia
Life cycle types: 'Haplo(n) → Diplo(2n) → Haplo-Diplo(both)' in order of complexity
🧬 Biology
Morphology of Flowering Plants
⏱ ~2 min
- •Root types: tap root (dicots) and fibrous/adventitious root (monocots)
- •Root modifications: storage (carrot, radish), prop roots (banyan), pneumatophores (Rhizophora)
- •Stem modifications: tuber (potato), bulb (onion), rhizome (ginger), corm (colocasia), runner (grass)
- •Leaf parts: lamina, petiole, leaf base; venation: reticulate (dicots), parallel (monocots)
- •Compound leaves: pinnate (neem) and palmate (silk cotton); leaflets do NOT have axillary buds
- •Phyllotaxy: alternate (sunflower), opposite (Calotropis), whorled (Alstonia)
- •Inflorescence types: racemose (flowers acropetally) and cymose (flowers basipetally)
- •Flower parts: calyx (sepals), corolla (petals), androecium (stamens), gynoecium (carpels)
- +8 more key facts
💡 Mnemonics
Stem modifications: 'TBRRC' — Tuber (potato), Bulb (onion), Rhizome (ginger), Runner, Corm
Placentation: 'MAPBF' — Marginal, Axile, Parietal, Basal, Free central
Floral families for NEET: 'SFL' — Solanaceae, Fabaceae, Liliaceae (learn floral formulas)
Root modifications: 'CPP' — Carrot/Radish (storage), Prop (banyan), Pneumatophore (mangrove)
🧬 Biology
Reproductive Health
⏱ ~2 min
- •Reproductive health: total well-being in physical, emotional, behavioural, and social aspects of reproduction
- •India was the first country to initiate a national family planning programme (1951)
- •Natural contraception methods: periodic abstinence (rhythm method), coitus interruptus, lactational amenorrhoea
- •Barrier methods: condoms (male/female), diaphragm, cervical cap, vaults — prevent sperm entry
- •IUDs: non-medicated (Lippes loop), Cu-releasing (CuT, Cu7, Multiload 375), hormone-releasing (LNG-20, Progestasert)
- •Oral contraceptive pills (OCPs): synthetic progesterone + estrogen; inhibit ovulation
- •Emergency contraception: within 72 hours of unprotected intercourse (e.g., levonorgestrel)
- •Surgical methods: vasectomy (male — vas deferens cut) and tubectomy (female — fallopian tube cut)
- +8 more key facts
💡 Mnemonics
IUD types: 'NCH' — Non-medicated, Copper, Hormonal
ART techniques: 'GIZ' — GIFT, IVF/ICSI, ZIFT — in order of where transfer happens
STD bacteria: 'GS' — Gonorrhoea (Neisseria gonorrhoeae), Syphilis (Treponema pallidum)
Contraceptive methods: 'Natural-Barrier-IUD-Oral-Injectable-Surgical' → least to most intervention
🧬 Biology
Human Health & Disease
⏱ ~2 min
- •Innate immunity: non-specific, present from birth; includes barriers (skin, mucus), phagocytes, NK cells, complement
- •Acquired immunity: specific, develops after exposure; humoral (B-cells, antibodies) and cell-mediated (T-cells)
- •Active immunity: body produces antibodies (natural — infection, artificial — vaccine)
- •Passive immunity: preformed antibodies given (natural — mother to fetus via placenta, artificial — antiserum)
- •Vaccination: based on immune system memory; attenuated or killed pathogens used
- •Malaria: caused by Plasmodium (P. vivax, P. falciparum), vector is female Anopheles mosquito
- •Plasmodium life cycle: sporozoites (infective) → liver → merozoites → RBCs → gametocytes → mosquito
- •Filariasis (elephantiasis): Wuchereria bancrofti, vector is Culex mosquito, affects lymphatic system
- +10 more key facts
💡 Mnemonics
Immunity types: 'APCM' — Active (self-made), Passive (received), Cell-mediated (T-cells), huMoral (B-cells/antibodies)
Malaria parasites in NEET: 'VF' — Vivax (benign tertian, 48h), Falciparum (malignant, most dangerous)
AIDS progression: 'HIV → CD4 T-cells ↓ → opportunistic infections → AIDS (CD4 < 200)'
Drug types: 'OCLC' — Opioids, Cannabinoids, LSD, Cocaine
🧬 Biology
Microbes in Human Welfare
⏱ ~2 min
- •Lactobacillus: converts milk to curd (lactic acid fermentation); increases vitamin B₁₂
- •Saccharomyces cerevisiae (brewer's yeast): alcoholic fermentation, bread making, ethanol production
- •Antibiotics: Penicillin from Penicillium notatum (Alexander Fleming); first antibiotic
- •Fermented foods: idli/dosa (Leuconostoc), cheese (Propionibacterium shermanii for Swiss cheese)
- •Roquefort cheese: ripened with Penicillium roqueforti for flavor
- •Biogas (gobar gas): mainly methane (CH₄); produced by methanogens (Methanobacterium) in anaerobic conditions
- •Biogas plant: slurry → digester (anaerobic) → biogas (CH₄ + CO₂ + H₂S) + spent slurry (fertilizer)
- •Sewage treatment: primary (sedimentation) → secondary (biological/aerobic — activated sludge, trickling filters) → tertiary
- +9 more key facts
💡 Mnemonics
Fermented products: 'CIVIC BW' — Curd (Lactobacillus), Idli (Leuconostoc), Vinegar (Acetobacter), Cheese, Bread/Wine (yeast)
Biofertilizers N₂-fixers: 'RAC' — Rhizobium (symbiotic), Azotobacter (free-living), Cyanobacteria (Anabaena/Nostoc)
Sewage treatment order: 'PST' — Primary, Secondary, Tertiary
Microbe products: 'PECS' — Penicillin, Ethanol, Cyclosporin, Statins
🧬 Biology
Biodiversity & Conservation
⏱ ~2 min
- •Biodiversity: variety of life at genetic, species, and ecological/ecosystem levels
- •Species-area relationship: log S = log C + Z log A (S = species richness, A = area)
- •Z value (regression coefficient): typically 0.1–0.3 for small areas; ~0.6–0.7 for large areas (continents/islands)
- •Estimated global species: ~8.1 million; India has ~8.1% of global species (mega-diversity nation)
- •Biodiversity hotspots: regions with high endemism and high habitat loss; 34 global hotspots
- •India has 4 biodiversity hotspots: Western Ghats, Himalayas, Indo-Burma, Sundaland
- •IUCN Red List categories: Extinct, Critically Endangered, Endangered, Vulnerable, Near Threatened, Least Concern
- •Red Data Book: records endangered species; maintained by IUCN
- +8 more key facts
💡 Mnemonics
India's hotspots: 'WISH' — Western Ghats, Indo-Burma, Sundaland, Himalayas
Evil Quartet: 'HOAC' — Habitat loss, Overexploitation, Alien species, Co-extinction
Conservation types: 'In situ = IN habitat; Ex situ = EXit habitat'
IUCN categories: 'ECEVNL' — Extinct, Critically Endangered, Endangered, Vulnerable, Near Threatened, Least Concern
🧬 Biology
Body Fluids and Circulation
⏱ ~2 min
- •Blood components: plasma (55%) and formed elements (45%) — RBCs, WBCs, platelets
- •Plasma proteins: albumins (osmotic balance), globulins (immunity), fibrinogen (clotting)
- •RBCs are biconcave, enucleated (in mammals), contain haemoglobin; lifespan ~120 days
- •WBC types: granulocytes (neutrophils, eosinophils, basophils) and agranulocytes (lymphocytes, monocytes)
- •Neutrophils: most abundant WBC (~60–65%); first responders in infection (phagocytosis)
- •Blood groups: ABO system (Landsteiner) and Rh factor; based on antigens on RBC surface
- •Blood group O: universal donor (no antigens); AB: universal recipient (no antibodies)
- •Rh incompatibility: Rh⁻ mother with Rh⁺ fetus → erythroblastosis fetalis in 2nd pregnancy
- +8 more key facts
💡 Mnemonics
WBC order (most to least): 'Never Let Monkeys Eat Bananas' → Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils
Conduction pathway: 'SABP' → SA node, AV node, Bundle of His, Purkinje fibres
Blood group antigens: 'A has A antigen + b antibody; B has B antigen + a antibody; AB has both antigens, no antibodies; O has no antigens, both antibodies'
Cardiac cycle: '0.1 + 0.3 + 0.4 = 0.8 sec' → atrial systole, ventricular systole, joint diastole
🧬 Biology
Excretory Products & Their Elimination
⏱ ~2 min
- •Excretion: removal of metabolic waste products (urea, uric acid, ammonia, CO₂)
- •Ammonotelic: excrete ammonia (aquatic animals — fish, tadpoles); requires lots of water
- •Ureotelic: excrete urea (mammals, adult amphibians); less toxic, less water needed
- •Uricotelic: excrete uric acid (birds, reptiles, insects); least toxic, least water needed
- •Kidney structure: cortex (outer), medulla (inner, renal pyramids), hilum, renal pelvis
- •Nephron: functional unit of kidney; ~1 million per kidney in humans
- •Nephron parts: Bowman's capsule, PCT, Loop of Henle, DCT, collecting duct
- •Glomerular filtration: blood filtered in glomerulus → Bowman's capsule; GFR = 125 mL/min
- +10 more key facts
💡 Mnemonics
Excretion types: 'AUU' — Ammonotelic (aquatic), Ureotelic (mammals), Uricotelic (birds/reptiles)
Nephron segments: 'BPLDCC' → Bowman's capsule, PCT, Loop of Henle, DCT, Collecting duct
Hormones on kidney: 'AAA' — ADH (water reabsorption), Aldosterone (Na⁺ reabsorption), ANF (opposes both)
GFR math: '125 mL/min × 60 × 24 = 180 L/day filtered, but only ~1.5 L urine excreted (99% reabsorbed)'
🧬 Biology
Neural Control & Coordination
⏱ ~2 min
- •Neuron: structural and functional unit of nervous system; types — sensory, motor, interneuron
- •Neuron structure: cell body (soma), dendrites (receive signals), axon (transmit signals)
- •Myelinated nerve fibres: Schwann cells form myelin sheath; nodes of Ranvier between them
- •Resting potential: −70 mV (inside negative); maintained by Na⁺-K⁺ ATPase pump
- •Action potential: depolarization (Na⁺ influx) → repolarization (K⁺ efflux) → hyperpolarization
- •Saltatory conduction: impulse jumps between nodes of Ranvier in myelinated fibres — faster
- •Synapse: junction between two neurons; types — chemical (neurotransmitter) and electrical
- •Chemical synapse: presynaptic → neurotransmitter (acetylcholine) → postsynaptic receptor → signal
- +10 more key facts
💡 Mnemonics
Brain parts: 'CHM' — Cerebrum (thinking), Hypothalamus (homeostasis), Medulla (vital reflexes)
Ear ossicles: 'MIS' — Malleus, Incus, Stapes (hammer, anvil, stirrup) — smallest bones in body
Cranial nerves count: 12 pairs; Spinal nerves: 31 pairs
Reflex arc order: 'RACE' — Receptor, Afferent, Centre (CNS), Efferent → effector
🧬 Biology
Locomotion & Movement
⏱ ~2 min
- •Muscle types: skeletal (striated, voluntary), smooth (visceral, involuntary), cardiac (striated, involuntary)
- •Skeletal muscle structure: fascicle → muscle fibre → myofibril → sarcomere (functional unit)
- •Sarcomere: A band (dark, myosin), I band (light, actin), H zone (only myosin), Z line (boundary)
- •During contraction: I band and H zone decrease; A band remains constant; sarcomere shortens
- •Sliding filament theory: actin slides over myosin; needs ATP and Ca²⁺
- •Muscle contraction sequence: nerve impulse → Ca²⁺ release from sarcoplasmic reticulum → Ca²⁺ binds troponin → tropomyosin shifts → actin-myosin cross-bridge → power stroke
- •ATP role: needed for cross-bridge cycling (power stroke) and detachment of myosin head
- •Rigor mortis: after death, no ATP → myosin heads cannot detach → muscles stiffen
- +9 more key facts
💡 Mnemonics
Sarcomere bands during contraction: 'IH decrease, A stays' — I band, H zone shrink; A band constant
Contraction sequence: 'NICE CPC' — Nerve impulse, Ion (Ca²⁺) release, Cross-bridge, Power stroke, Cycle
Total bones: '80 + 126 = 206' — Axial (80) + Appendicular (126) = Total (206)
Joint types: 'SyCaFi' — Synovial (freely movable), Cartilaginous (slightly), Fibrous (immovable)
🧬 Biology
Chemical Coordination & Integration
⏱ ~2 min
- •Endocrine glands: ductless, secrete hormones directly into blood; exocrine glands have ducts
- •Hypothalamus: master of master gland; releases releasing/inhibiting hormones controlling pituitary
- •Anterior pituitary hormones: GH, TSH, ACTH, FSH, LH, Prolactin
- •Posterior pituitary: stores and releases oxytocin (milk ejection, uterine contractions) and ADH (water reabsorption)
- •Thyroid gland: T₃ (triiodothyronine) and T₄ (thyroxine) — regulate BMR; need iodine
- •Hypothyroidism: cretinism (children), myxoedema (adults); goitre from iodine deficiency
- •Hyperthyroidism: Graves' disease — exophthalmic goitre, increased BMR, weight loss
- •Parathyroid (PTH): increases blood Ca²⁺ (from bones); calcitonin (thyroid): decreases blood Ca²⁺
- +9 more key facts
💡 Mnemonics
Anterior pituitary: 'FLAT PG' — FSH, LH, ACTH, TSH, Prolactin, GH
Adrenal cortex layers: 'GFR — Salt Sugar Sex' — Glomerulosa (mineralocorticoids), Fasciculata (glucocorticoids), Reticularis (sex hormones)
Ca²⁺ regulation: 'PTH ↑ Ca²⁺ (Parathyroid); Calcitonin ↓ Ca²⁺ (thyroid C-cells)' → PCT: Para-Cal-Thyroid
Pancreas hormones: 'Alpha = Glucagon (↑glucose); Beta = Insulin (↓glucose)' — Alphabetically, A before B, Glucagon before Insulin
🧬 Biology
Digestion and Absorption
⏱ ~2 min
- •Alimentary canal: mouth → pharynx → oesophagus → stomach → small intestine → large intestine → anus
- •Salivary glands: parotid, submandibular, sublingual; secrete salivary amylase (ptyalin) — starch → maltose (pH 6.8)
- •Stomach: fundic glands secrete HCl, pepsinogen, mucus; pH 1.5–2.0
- •HCl activates pepsinogen → pepsin (active protease); kills bacteria; provides acidic pH
- •Gastric lipase partially digests fats; rennin (infants) curdles milk protein casein
- •Pancreatic juice: trypsinogen (activated by enterokinase → trypsin), chymotrypsinogen, lipase, amylase, nucleases
- •Bile: produced by liver, stored in gallbladder; bile salts emulsify fats (no enzymes)
- •Small intestine: duodenum (receives bile + pancreatic juice), jejunum, ileum (max absorption)
- +8 more key facts
💡 Mnemonics
GI tract order: 'Mother Passes Eggs Straight, Small Lazy Children Are Rare' — Mouth, Pharynx, Esophagus, Stomach, Small intestine, Large intestine, Caecum, Appendix, Rectum
Pancreatic enzymes: 'TCA-LN' — Trypsin, Chymotrypsin, Amylase, Lipase, Nuclease
Fat digestion: 'Bile Emulsifies → Lipase Digests → Lacteals Absorb'
PEM: 'Marasmus = M (more deficiency — both protein + calories); Kwashiorkor = K (protein deficiency only)'
🧬 Biology
Breathing & Exchange of Gases
⏱ ~2 min
- •Respiratory system: nostrils → pharynx → larynx → trachea → bronchi → bronchioles → alveoli
- •Alveoli: thin-walled, highly vascularized, site of gas exchange; total surface area ~100 m²
- •Breathing mechanism: inspiration (active — diaphragm contracts, external intercostals contract) and expiration (passive — diaphragm relaxes)
- •Tidal volume (TV): ~500 mL — volume of air inspired/expired during normal breathing
- •Inspiratory reserve volume (IRV): ~2500–3000 mL (extra air that can be inhaled after normal inspiration)
- •Expiratory reserve volume (ERV): ~1000–1100 mL (extra air that can be exhaled after normal expiration)
- •Residual volume (RV): ~1200 mL — air remaining in lungs after forceful expiration
- •Vital capacity = TV + IRV + ERV (~3500–4500 mL)
- +10 more key facts
💡 Mnemonics
Lung volumes: 'TIER' — Tidal, IRV, ERV, Residual; VC = T + I + E; TLC = VC + R
O₂ transport percentages: '97-3' — 97% as HbO₂, 3% dissolved
CO₂ transport: '70-23-7' — 70% bicarbonate, 23% carbaminohaemoglobin, 7% dissolved
Bohr effect: 'Right shift = Release O₂' — high CO₂/H⁺ shifts curve right
⚗️
Chemistry
4 chapters0/4 done⚗️ Chemistry
Chemical Bonding
⏱ ~2 min
- •Octet rule: atoms tend to achieve 8 electrons in valence shell (exceptions: H, Li, Be, B, P, S)
- •Ionic bond: transfer of electrons; forms between metals and non-metals (high ΔEN)
- •Covalent bond: sharing of electrons; forms between non-metals (low ΔEN)
- •Bond order = (bonding electrons − antibonding electrons) / 2
- •VSEPR theory: molecular geometry depends on electron pairs around central atom
- •sp hybridization → linear (180°); sp² → trigonal planar (120°); sp³ → tetrahedral (109.5°)
- •sp³d → trigonal bipyramidal; sp³d² → octahedral
- •Sigma bonds: head-on overlap (stronger); Pi bonds: lateral overlap (weaker)
- +12 more key facts
📐 Formulas
Bond order = (Nb − Na) / 2
Dipole moment: μ = q × d (Debye units)
Formal charge = Valence electrons − (Lone pair electrons + Bonding electrons/2)
Lattice energy ∝ (q₊ × q₋) / (r₊ + r₋)
% ionic character = (observed μ / calculated μ for 100% ionic) × 100
💡 Mnemonics
Hybridization from electron pairs: '2=sp, 3=sp², 4=sp³, 5=sp³d, 6=sp³d²'
VSEPR shapes: 'Linear, Trigonal Planar, Tetrahedral, TBP, Octahedral' for 2-6 electron domains
H-bond strength: 'FoN' — F > O > N
MO order change: 'BON' (B₂, O₂ changes) — actually B₂, C₂, N₂ have π before σ
⚗️ Chemistry
Organic Chemistry Reactions
⏱ ~2 min
- •Markovnikov's rule: H adds to C with more H's; anti-Markovnikov with HBr + peroxide
- •SN1: 2 steps, carbocation intermediate, racemization, favoured by 3° substrate + polar protic solvent
- •SN2: 1 step, backside attack, Walden inversion, favoured by 1° substrate + polar aprotic solvent + strong nucleophile
- •E1: 2 steps, carbocation, Zaitsev product (more substituted alkene); competes with SN1
- •E2: 1 step, strong base, anti-periplanar geometry, Zaitsev product
- •Electrophilic aromatic substitution (EAS): halogenation, nitration, sulphonation, Friedel-Crafts
- •Activating groups (EDG): −OH, −NH₂, −OR are ortho/para directors
- •Deactivating groups (EWG): −NO₂, −COOH, −CHO are meta directors (except halogens → o/p)
- +12 more key facts
📐 Formulas
Degree of unsaturation = (2C + 2 + N − H − X) / 2
Grignard: R-MgX + R'CHO → R-R'CHOH (2° alcohol after hydrolysis)
Aldol: 2 CH₃CHO → CH₃CH(OH)CH₂CHO (β-hydroxy aldehyde)
Cannizzaro: 2 HCHO + NaOH → HCOONa + CH₃OH
💡 Mnemonics
SN1 vs SN2: '1 = unimolecular = 2 steps; 2 = bimolecular = 1 step (confusingly opposite!)'
Ortho/para directors: electron donors — 'NORTH Para' (NH₂, OH, R, halogens push o/p)
Named reactions: 'CRACK' — Cannizzaro, Reimer-Tiemann, Aldol, Clemmensen, Kolbe
Lucas test timing: '3-2-1 Go!' — 3° instant, 2° slow, 1° no reaction
⚗️ Chemistry
Thermodynamics & Equilibrium
⏱ ~2 min
- •First law: ΔU = q + w (IUPAC sign convention); energy is conserved
- •Enthalpy: H = U + PV; at constant pressure, ΔH = qₚ
- •Exothermic: ΔH < 0 (heat released); Endothermic: ΔH > 0 (heat absorbed)
- •Hess's law: total ΔH is path-independent; depends only on initial and final states
- •Bond dissociation energy: ΔH_rxn = Σ(BDE reactants) − Σ(BDE products)
- •Entropy (S): measure of disorder; ΔS_universe > 0 for spontaneous process
- •Gibbs free energy: ΔG = ΔH − TΔS; spontaneous if ΔG < 0
- •At equilibrium: ΔG = 0 and ΔG° = −RT ln K
- +12 more key facts
📐 Formulas
ΔG = ΔH − TΔS
ΔG° = −RT ln K = −2.303 RT log K
Kp = Kc(RT)^Δn
pH = pKa + log([A⁻]/[HA]) (Henderson-Hasselbalch)
w = −nRT ln(V₂/V₁) for isothermal reversible expansion
Cp − Cv = R (for 1 mol of ideal gas)
ΔH = ΔU + ΔnₘRT (relation between ΔH and ΔU)
Ksp = [cation]ᵐ[anion]ⁿ for AₘBₙ type salt
💡 Mnemonics
Spontaneity check: 'GHoST' — G = H − TS (Gibbs = entHalpy − Temperature × entropy)
Exo vs Endo: 'EXit = energy EXits (exothermic, ΔH < 0)'
Le Chatelier: 'System opposes the stress' — increase conc → shifts away from it
Buffer: 'WASSaB' — Weak Acid + Salt of its conjugate base = Acidic Buffer
⚗️ Chemistry
Coordination Compounds
⏱ ~2 min
- •Coordination number = number of ligand donor atoms directly bonded to central metal ion
- •IUPAC naming: cation first, then anion; ligands in alphabetical order before metal name
- •Anionic complex: metal ends in '-ate' (e.g., ferrate, cuprate, aluminate)
- •Werner's theory: primary valence = oxidation state; secondary valence = coordination number
- •Chelation: polydentate ligands form ring structures → extra stability (chelate effect)
- •EDTA is a hexadentate ligand (6 donor atoms: 4 O + 2 N)
- •Spectrochemical series: I⁻ < Br⁻ < Cl⁻ < F⁻ < OH⁻ < H₂O < NH₃ < en < NO₂⁻ < CN⁻ < CO
- •Weak field ligands (left of series) → high spin; Strong field ligands (right) → low spin
- +12 more key facts
📐 Formulas
Magnetic moment: μ = √(n(n+2)) BM
Δₜ = (4/9) Δₒ
CFSE (octahedral) = (−0.4x + 0.6y)Δₒ + pairing energy; x = t₂g electrons, y = eg electrons
EAN = Z − oxidation state + 2 × (coordination number)
💡 Mnemonics
Spectrochemical series: 'I Bring Cl For Our House Neatly Everyday, NO Cyanide, CO!' (I⁻ < Br⁻ < Cl⁻ < F⁻ < OH⁻ < H₂O < NH₃ < en < NO₂⁻ < CN⁻ < CO)
Octahedral d-orbital splitting: 't₂g = dxy, dyz, dxz (lower); eg = dx²−y², dz² (upper)'
Naming order: 'Alphabetical Ligands + Metal(oxidation state)' for cation; add '-ate' for anion
Common denticity: 'EDTA=6, en=2, oxalate=2, DMGN=2'
⚛️
Physics
4 chapters0/4 done⚛️ Physics
Mechanics (Newton's Laws + WEP)
⏱ ~2 min
- •Newton's First Law (inertia): body continues in uniform motion unless acted on by external force
- •Newton's Second Law: F = dp/dt = ma (for constant mass); defines force quantitatively
- •Newton's Third Law: every action has equal and opposite reaction; forces act on DIFFERENT bodies
- •Friction: static friction ≥ kinetic friction; fs(max) = μsN, fk = μkN
- •Free body diagrams: isolate body, draw all external forces, apply F = ma for each axis
- •Pseudo force: −ma₀ applied in non-inertial frame (a₀ = acceleration of frame)
- •Work done: W = F·d·cos θ; positive if force and displacement in same direction
- •Work-Energy theorem: net work done = change in kinetic energy (Wnet = ΔKE)
- +12 more key facts
📐 Formulas
F = ma (Newton's 2nd law)
W = Fd cos θ
KE = ½mv², PE = mgh, Spring PE = ½kx²
P = Fv = dW/dt
Impulse J = FΔt = Δp
Centripetal acceleration: ac = v²/r = ω²r
Banking angle: tan θ = v²/rg
Coefficient of restitution: e = (v₂ − v₁)/(u₁ − u₂)
💡 Mnemonics
Newton's laws: '1st = LAZY (inertia), 2nd = F=ma (quantitative), 3rd = REACTION (equal opposite)'
Energy conservation: 'KEPE = constant when only gravity/spring forces act'
Collision types: 'Elastic = Everything conserved; Inelastic = only Impulse (momentum) conserved'
Power units: 'Watt = Joule per second; 1 HP = 746 W'
⚛️ Physics
Optics (Ray + Wave)
⏱ ~2 min
- •Snell's law: n₁ sin θ₁ = n₂ sin θ₂; defines refraction at interface
- •Total internal reflection: when angle of incidence > critical angle (sin θc = n₂/n₁, n₁ > n₂)
- •Mirror formula: 1/v + 1/u = 1/f; lens formula: 1/v − 1/u = 1/f (sign convention matters!)
- •Power of lens: P = 1/f (in metres); SI unit: dioptre (D); convex (+), concave (−)
- •Magnification: m = −v/u (mirror) = v/u (lens); m < 0 means inverted image
- •Lensmaker's equation: 1/f = (μ − 1)(1/R₁ − 1/R₂)
- •Combination of thin lenses in contact: 1/f = 1/f₁ + 1/f₂; P = P₁ + P₂
- •Dispersion: splitting of white light; violet bends most (highest μ), red bends least
- +12 more key facts
📐 Formulas
Snell's law: n₁ sin θ₁ = n₂ sin θ₂
Mirror: 1/v + 1/u = 1/f
Lens: 1/v − 1/u = 1/f
Lensmaker: 1/f = (μ − 1)(1/R₁ − 1/R₂)
Power: P = 1/f (in metres) [unit: Dioptre]
Fringe width: β = λD/d
Brewster's angle: tan θB = μ
Malus's law: I = I₀ cos² θ
💡 Mnemonics
Sign convention: 'Real is Negative for mirrors (incident light direction is +ve)'
Myopia-Hypermetropia: 'MY = Minus (concave lens), HY = Hypermetropia = Plus (convex)'
VIBGYOR: Violet has highest frequency and refractive index; Red has lowest
TIR conditions: 'Denser to Rarer + angle > critical angle'
⚛️ Physics
Electrostatics & Current Electricity
⏱ ~2 min
- •Coulomb's law: F = kq₁q₂/r² (k = 9 × 10⁹ Nm²/C²); inverse square law
- •Electric field: E = F/q₀ = kQ/r² (point charge); direction: away from +, toward −
- •Electric potential: V = kQ/r; potential is scalar, adds algebraically
- •Gauss's law: Φ = q_enclosed/ε₀; useful for symmetric charge distributions
- •Field inside a conductor = 0; field just outside = σ/ε₀ (perpendicular to surface)
- •Capacitance: C = Q/V; parallel plate: C = ε₀A/d; with dielectric: C = Kε₀A/d
- •Capacitors in series: 1/C = 1/C₁ + 1/C₂; in parallel: C = C₁ + C₂
- •Energy stored in capacitor: U = ½CV² = ½QV = Q²/2C
- +12 more key facts
📐 Formulas
F = kq₁q₂/r² (k = 1/4πε₀ = 9 × 10⁹ Nm²/C²)
E = kQ/r², V = kQ/r
C = ε₀A/d (parallel plate), C = Kε₀A/d (with dielectric)
U = ½CV² = Q²/2C
V = IR, R = ρL/A
P = VI = I²R = V²/R
vd = I/(nAe)
Wheatstone balance: P/Q = R/S
💡 Mnemonics
Capacitor combos: 'Series = reciprocal sum (like parallel resistors); Parallel = direct sum (like series resistors)' — OPPOSITE of resistors!
Kirchhoff's laws: 'KCL = Current conservation at Junction; KVL = Voltage sum around Loop = 0'
Electric field direction: 'Positive charge pushes field lines OUT; Negative pulls IN'
Power formulas: 'VIR-PIV: P=VI, V=IR (triangle method)'
⚛️ Physics
Modern Physics
⏱ ~3 min
- •Photoelectric effect: E = hν − φ (KE_max = hν − work function); threshold frequency ν₀ = φ/h
- •Stopping potential: eV₀ = hν − φ; V₀ is independent of intensity
- •Photon energy: E = hν = hc/λ; momentum of photon: p = h/λ = E/c
- •de Broglie wavelength: λ = h/mv = h/p; matter waves for all particles
- •Bohr model: angular momentum L = nh/2π; radius rₙ = n²a₀/Z (a₀ = 0.529 Å)
- •Energy of H-atom: Eₙ = −13.6 Z²/n² eV; ground state (n=1): E₁ = −13.6 eV
- •Spectral series: Lyman (UV, to n=1), Balmer (visible, to n=2), Paschen (IR, to n=3)
- •Radioactive decay: N = N₀e^(−λt); half-life T½ = 0.693/λ; activity A = λN
- +12 more key facts
📐 Formulas
E = hν = hc/λ (photon energy)
KE_max = hν − φ (photoelectric effect)
λ = h/mv = h/p (de Broglie wavelength)
Eₙ = −13.6 Z²/n² eV (Bohr energy levels)
rₙ = 0.529 × n²/Z Å (Bohr radius)
N = N₀e^(−λt), T½ = 0.693/λ (radioactive decay)
BE = Δm × c² = Δm × 931.5 MeV (binding energy)
1/λ = R(1/n₁² − 1/n₂²) (hydrogen spectrum)
Δx · Δp ≥ h/4π (uncertainty principle)
R = R₀A^(1/3) (nuclear radius)
💡 Mnemonics
Spectral series: 'Lyman-Balmer-Paschen-Brackett-Pfund' → 'Lazy Boys Play Basketball Poorly' (n=1,2,3,4,5)
Photoelectric: 'KEmax depends on frequency NOT intensity; photocurrent depends on intensity NOT frequency'
Decay changes: 'Alpha: Z−2, A−4; Beta⁻: Z+1, A same; Gamma: nothing changes'
Bohr model: 'radius ∝ n², energy ∝ −1/n², velocity ∝ 1/n'
1 amu = 931.5 MeV/c² for mass-energy conversion