Biology
Biology is the most layered of the disciplines — molecular machinery on chemistry, on thermodynamics, on statistical mechanics, on probability and dynamics. The point of the unified curriculum is that each layer's claims trace back to the layer below it.
Units
17.01.01— Biomolecules in cells — overview shipped17.01.02— Protein structure: primary through quaternary, the Ramachandran plot, alpha-helix and beta-sheet stub17.01.03— Carbohydrate chemistry: monosaccharides, glycosidic bonds, polysaccharides, and glycoconjugates stub17.01.04— Lipid chemistry: fatty acids, glycerophospholipids, sphingolipids, sterols, and their roles stub17.02.01— Cell membranes: structure shipped17.02.02— Membrane transport — passive and active shipped17.02.03— Membrane proteins: integral versus peripheral, topology, and lipid-protein interactions stub17.02.04— Vesicle trafficking: SNARE proteins, clathrin-coated vesicles, and the secretory pathway stub17.03.01— Cellular organization: organelles shipped17.03.02— Cytoskeleton and contractile proteins shipped17.03.03— Nucleus and nuclear transport: nuclear pore complex, importins, exportins, and chromatin organization stub17.03.04— Endoplasmic reticulum and Golgi: protein folding, glycosylation, and vesicle budding stub17.04.01— Cellular respiration: glycolysis and CAC shipped17.04.02— Oxidative phosphorylation and ATP synthesis shipped17.04.03— Photosynthesis: light and dark reactions shipped17.04.04— Fatty acid metabolism: beta-oxidation, fatty acid synthesis, and the acetyl-CoA hub stub17.04.05— Amino acid catabolism: transamination, the urea cycle, and amino acid biosynthesis overview stub17.04.06— Metabolic regulation: allosteric control, covalent modification, and the AMP kinase switch stub17.05.01— DNA replication shipped17.05.02— Transcription shipped17.05.03— Translation shipped17.05.04— RNA processing: 5-prime capping, splicing, 3-prime polyadenylation, and alternative splicing stub17.05.05— Ribosomes and the genetic code: codon-anticodon recognition and aminoacyl-tRNA synthetases stub17.06.01— Mutation and repair shipped17.06.02— DNA repair pathways: base excision, nucleotide excision, mismatch repair, and double-strand break repair stub17.06.03— Transposable elements: mechanisms of transposition, genome evolution, and epigenetic silencing stub17.06.04— Epigenetics: histone modification, DNA methylation, X-inactivation, and imprinting stub17.07.01— Cell signaling: receptors and GPCRs shipped17.07.02— Receptor tyrosine kinases and the MAPK signaling cascade shipped17.07.03— PI3K-Akt-mTOR pathway: growth factor response, nutrient sensing, and cancer connections stub17.07.04— NF-kB and JAK-STAT pathways: cytokine signaling and transcriptional responses stub17.08.01— Cell cycle and mitosis shipped17.08.02— Cyclin-CDK complexes: regulation of each cell cycle transition and checkpoint mechanisms stub17.08.03— Meiosis: recombination, crossing over, and the generation of genetic diversity stub17.08.04— Apoptosis: intrinsic and extrinsic pathways, the caspase cascade, and Bcl-2 family regulation stub17.09.01— Resting membrane potential and ion channels shipped17.09.02— The action potential — ionic basis shipped17.09.03— Synaptic transmission: neurotransmitter release, SNARE-dependent exocytosis, and receptor gating stub17.09.04— Ion channel pharmacology: channel types, blockers, and the molecular basis of excitability stub17.10.01— Innate immunity at the molecular level shipped17.10.02— Adaptive immunity overview: B cells, T cells, clonal selection, and the antibody response stub17.10.03— MHC and antigen presentation: class I and II pathways, and T cell activation stub17.10.04— Antibody structure and diversity: V(D)J recombination, affinity maturation, and isotype switching stub17.11.01— Cell and molecular biology methods — microscopy, PCR, sequencing, CRISPR shipped17.11.02— Optical tweezers and single-molecule force spectroscopy shipped17.11.03— CRISPR-Cas9 genome editing: PAM recognition, sgRNA guidance, and DSB repair outcomes shipped17.12.01— Cytoskeleton, molecular motors, and cell motility shipped17.12.02— Molecular motors: kinesin, dynein, and myosin mechanics shipped18.01.01— Body plans and organization shipped18.01.02— Body plan diversity: symmetry types, coelom origins, and the major animal phyla stub18.01.03— The Ediacaran biota, the Cambrian explosion, and the origin of animals shipped18.02.01— Cardiovascular physiology — the heart shipped18.02.02— Cardiac action potentials, pacemaker physiology, and the ECG shipped18.02.03— Hemodynamics: Poiseuille's law, Laplace's law, and blood pressure regulation stub18.02.04— The cardiac cycle: systole and diastole, the Wiggers diagram, and cardiac output regulation stub18.02.05— Cardiac gap junctions: connexin architecture, intercellular coupling, and arrhythmia shipped18.03.01— Respiratory physiology — gas exchange and transport shipped18.03.02— Lung mechanics: compliance, surfactant, the work of breathing, and spirometry values stub18.03.03— Gas exchange and transport: the oxygen-hemoglobin dissociation curve and CO2 transport as bicarbonate stub18.03.04— Control of ventilation: medullary rhythmogenesis, central and peripheral chemoreceptors, and integrated ventilatory response shipped18.04.01— Skeletal muscle physiology shipped18.04.02— Muscle contraction — the actin-myosin cycle shipped18.04.03— Motor unit recruitment and fatigue: slow versus fast twitch, the size principle, and graded force stub18.04.04— Skeletal mechanics: bone remodeling, joint biomechanics, and the lever principles stub18.04.05— Bone remodeling and osteoporosis: RANKL-RANK-OPG signaling, bisphosphonates, and the Frost mechanostat shipped18.05.01— Nervous system — gross anatomy and systems shipped18.05.02— Spinal cord and reflex arcs: monosynaptic stretch reflex, reciprocal inhibition, and pain pathways stub18.05.03— Brain regions: cerebral cortex functional areas, basal ganglia, cerebellum, and limbic system stub18.05.04— The autonomic nervous system: sympathetic versus parasympathetic, neurotransmitters, and homeostasis stub18.06.01— Digestive physiology and nutrition shipped18.06.02— Gastrointestinal motility and secretion: peristalsis, gastric acid, enzymes, and absorption sites stub18.06.03— Nutrient absorption: monosaccharides, amino acids, lipid micelles, and the enterohepatic circulation stub18.06.04— The gut-brain axis: vagal signaling, the microbiome, and enteric neuroscience shipped18.07.01— Endocrine system — hormones and regulation shipped18.07.02— Hypothalamic-pituitary axis: releasing hormones, tropic hormones, and feedback regulation stub18.07.03— Glucose homeostasis: insulin and glucagon action, the fed versus fasted state, and diabetes mechanisms stub18.07.04— Thyroid hormones and metabolic regulation: HPT axis, iodine biochemistry, and autoimmune thyroid disease shipped18.08.01— Renal physiology — homeostasis and the nephron shipped18.08.02— Nephron function: filtration, tubular reabsorption, secretion, and the countercurrent multiplier stub18.08.03— Acid-base balance: the bicarbonate buffer system, respiratory and metabolic compensation stub18.08.04— The renin-angiotensin-aldosterone system: RAAS physiology, hypertension, and ACE-inhibitor therapy shipped18.09.01— Reproductive biology shipped18.09.02— Gametogenesis: spermatogenesis and oogenesis, and hormonal control by FSH and LH stub18.09.03— Fertilization and early development: implantation, HCG signaling, and placental formation stub18.09.04— The menstrual cycle: HPO axis, follicular and luteal phases, and Knobil's discovery of pulsatile GnRH shipped18.10.01— Immunology shipped18.10.02— Inflammation: innate recognition via TLRs and NLRs, cytokine storm, and resolution mechanisms stub18.10.04— Vaccines and immunological memory: antigen presentation, B-cell clonal selection, and the principle of herd immunity shipped18.11.01— Embryology and morphogenesis shipped18.11.02— Gastrulation and axis formation: organizer signaling and Hox gene patterning stub18.11.03— Organogenesis: inductive interactions, morphogen gradients, and stem cell niches stub18.11.04— Induced pluripotent stem cells: the Yamanaka factors, reprogramming, and the regenerative-medicine revolution shipped18.12.01— Plant physiology — transport, photosynthesis, hormones, and stress shipped18.12.02— Photosynthesis pathways (C3/C4/CAM) and plant water relations shipped18.12.03— Plant hormones: auxin, gibberellin, ethylene, abscisic acid, and the control of plant development shipped18.13.01— Sensory systems — vision, hearing, balance, taste, smell shipped18.13.02— Hair cell mechanotransduction and cochlear frequency tuning shipped18.13.03— Chemosensation: taste, smell, and the Buck-Axel olfactory receptor revolution shipped18.13.04— Phototransduction: rod and cone physiology, the cGMP cascade, and the molecular basis of vision shipped19.01.01— Mendelian genetics — segregation and dominance shipped19.01.02— Linkage, crossing over, and genetic maps: LOD scores and recombination frequencies stub19.01.03— Sex-linked inheritance, dosage compensation, and X-inactivation stub19.02.01— Hardy-Weinberg equilibrium shipped19.02.02— Extensions of Hardy-Weinberg: multiple alleles, X-linked loci, and inbreeding stub19.02.03— Mutation-selection balance: the equilibrium frequency of deleterious alleles stub19.02.04— Migration and gene flow: the island model, FST, and genetic structure stub19.02.05— Wright-Fisher model and the diffusion approximation shipped19.03.01— Natural selection — directional, stabilizing, and disruptive shipped19.03.02— Sexual selection shipped19.03.03— Kin selection and Hamilton's rule shipped19.04.01— Genetic drift shipped19.04.02— Neutral theory: Kimura's neutral theory and synonymous versus nonsynonymous substitution rates stub19.04.03— Coalescent theory: the genealogy of a sample, TMRCA, and linkage disequilibrium stub19.05.01— Quantitative genetics — heritability and the breeder's equation shipped19.05.02— Twin studies and the estimation of heritability: additive versus dominance variance stub19.05.03— Polygenic adaptation and GWAS: quantitative trait loci and the infinitesimal model stub19.06.01— Speciation — allopatric and sympatric shipped19.06.02— Reinforcement, reproductive isolation, and alternatives to the biological species concept stub19.06.03— Hybrid zones and introgression: tension zones and the mosaic model stub19.06.04— Founder-effect and peripatric speciation: Mayr, genetic drift, and the founder-flush model shipped19.07.01— Phylogenetics — tree reconstruction shipped19.07.02— Molecular clock hypothesis: calibration, rate heterogeneity, and Bayesian divergence dating stub19.07.03— Character evolution: ancestral state reconstruction, Brownian motion, and Pagel's lambda stub19.08.01— Macroevolution shipped19.08.02— Mass extinctions: the Big Five, recovery dynamics, and the kill curve stub19.08.03— Trends in the fossil record: Cope's rule, the Red Queen hypothesis, and evolutionary stasis stub19.09.01— Population ecology — Lotka-Volterra shipped19.09.02— Metapopulation dynamics: the Levins model, rescue effect, and habitat fragmentation stub19.09.03— Age-structured populations: the Leslie matrix, stable age distribution, and reproductive value stub19.10.01— Community ecology — interactions and food webs shipped19.10.02— Succession: primary and secondary succession and the intermediate disturbance hypothesis stub19.10.03— Food webs, interaction strength, and trophic cascades shipped19.11.01— Ecosystem ecology shipped19.11.02— Ecosystem energy flow: trophic pyramids, primary productivity, and ecological efficiency stub19.11.03— Ecosystem stoichiometry: the Redfield ratio and nutrient limitation shipped19.12.01— Biogeography shipped19.12.02— Island biogeography and the species-area relationship shipped19.13.01— Coevolution shipped19.13.02— Coevolutionary arms races and the Red Queen hypothesis shipped19.13.02— Conservation strategies: population viability analysis, corridor design, and adaptive management stub19.14.01— Conservation biology shipped19.15.01— Origin of life — mechanistic scenarios shipped19.15.02— RNA world and prebiotic chemistry shipped19.16.01— Nutrient cycles: carbon, nitrogen, and phosphorus cycles and their anthropogenic disruption stub
Synthesis essays
Pan-bio questions that span sections — what life is, agency from chemotaxis up, information in biology. Lighter than tiered units; not graded for mastery.
- Essay 1. What life is — biology between physics and intentionality — Why the question won't take a single answer — and what the partial answers tell us about the kind of thing life is.
Coverage roadmap
Three top-level sections matching biology's three weakly-connected entry trees: §17 molecular & cellular biology (Alberts MBoC spine); §18 organismal & physiological biology (Campbell + Boron-Boulpaep spine); §19 ecology, evolution & population biology (Futuyma + Begon + Hartl-Clark spine). See the biology plan for tree-by-tree detail.