Notitiae Examen «Introductio ad Biologiam I»

Evolutio – Lux totius Biologiae

• Evolutio = mutatio sine directione præformata
• Idea unificans per omnes gradus: molecularis, organismicus, populationis
• Explicat simul unitatem et diversitatem vitæ
• Citatum Dobzhansky (1973): Nihil in biologia sensum habet nisi sub luce evolutionis

Darwin vs Lamarck

• Lamarck
  • Vita oritur generatione spontanea
  • Tendentia innata ad perfectionem
  • Via evolutionis linearis, progressiva
  • Hereditas characterum acquisitorum fundamentum adaptationis
• Darwin
  • Omnis diversitas e forma vita unica originaria
  • Descendentia cum modificatione, ramificatio plurima
  • Processus populationis : selectionis naturalis
  • Quaestiones post-Darwinianas
  • Origines variationis → Mutationes (Morgan)
  • Mechanismus hereditatis → Genetica (Mendel)
• Dictum modernum: Genes mutantur, organismi seliguntur, species evolvunt

Selectio naturalis

• Conditiones necessariæ & sufficientes
  1. Variatio phenotypica in populatione
  2. Variatio hereditaria est
  3. Correlatio inter caracterem & aptitudinem (supervivere/reproducere)
• Actio in individuis, effectus in frequentiis genicis
• Formula aptitudinis: $W = \dfrac{N<em>{desc}}{N</em>{max}}$
• Typi selectionis: directa, disruptiva, stabilis, sexualis

Origo Vitæ

• Evolutio chemica → Evolutio biologica
• Condiciones Terræ primitivæ (~$4.5\times10^9\,\text{annorum}$)
  • Atmosphæra reductrix (CO₂, CH₄, NH₃, H₂, H₂O etc.)
  • Nullus O₂ liber, nullum ozonum
• Experimentum Miller–Urey (1953)
  • Reproducit fulgura + gasos præ-bioticos → aminoacida, nucleotides, lipida
• Protocellula
  • Micellæ phospholipideæ + RNA autocatalyticum
  • Finis evolutionis abioticæ, initium evolutionis bioticæ
• RNA primus → sequentia naturalis $\text{DNA}\;\to\;\text{RNA}\;\to\;\text{Proteina}$

Bases Chemicæ Vitæ

• Macromoleculæ
  • Proteina (Aminoacida → peptida)
  • Acida nucleica (Nucleotida → polynucleotida)
  • Polisaccharida (Saccharida → glycani)
  • Lípida (structura heterogenea, insolubilia aqua)
• Interactiones
  • Covalentes: stabilitas skeletonis
  • Non covalentes (H-pontes, ionicæ, Van der Waals, effectus hydrophobus) → fundamentales structuris tertiary/quaternary
• Aqua: solvente biologicum, dipolum permanens, format pontes H

Bases Moleculares Hereditatis

• DNA duplex, antiparallelicus, helica dextrógira
• Complementaritas: $A=T,\;G=C$
• Replicatio semiconservativa; enzymata principalia
  • DNA-polymerasa (5′→3′), helicasa, primasa, ligasa, topoisomerasa
• Transcriptio (DNA → RNA)
  • Initiatio, elongatio, terminatio; in eucaryotis capping 5′, Splicing (intrones excisi), poly-A 3′
• Translatio (mRNA → polypeptidum)
  • Codex geneticus: 64 codones, redundantia non ambiguitas
  • tRNA anticodon + aminoacylatio (synthetasæ)

Mutationes & Reparatio

• Mutationes endogenæ (errores replicationis, deaminatio, ROS) & exogenæ (UV → dimeri timinæ, radiatio, chemica)
• Classificationes: punctualis, insertiones/deletiones, chromosomicae
• Systemata reparationis: photolyase, BER, NER, MMR

Bio-energetica & Metabolismus

• Metabolismus = Catabolismus + Anabolismus
• ATP = moneta energetica; hydrolysis $\Delta G^\circ \approx -30\,\text{kJ mol}^{-1}$
• Photosynthesis: complexus antenna + reactionis centrum, productio O₂, fundamentum aerobis
• Catena respiratoria & chemiosmosis (mitochondria): $\text{ADP}+P<em>i+H^+</em>{ex}\to ATP+H_2O$

Structura Cellulæ

Procaryotæ

• Paries celularis peptidoglycanicus; DNA circulare, haploide
• Fissio binaria (nulla mitosis)
• Variabilitas genetica: mutationes + transferentia horizontalis (transductio, coniugatio, transformatio)

Eucaryotæ

• Nucleus cum membrana duplici & poris
• Organella membranosa (mitochondria, reticulum endoplasmaticum, Golgi, lysosoma)
• Cytosceletum: microtubuli (tubulina), microfilamenta (actina), filamenta intermediaria
• Divisiones: mitosis (profase → telophase + cytokinesis), meiosis I & II (crossing-over, segregatio independentis)

Mors & Differentiatio Cellularis

• Apoptosis programmata (caspasæ, cytochromus c)
• Cellulæ matres: totipotentes, pluripotentes, multipotentes → regenerationes tissulorum

Hereditas Mendeliana

• Leges

1. Segregatio allelorum
2. Segregatio independens locorum non ligatorum

• Vocabula: genotypus, phenotypus, homozygosis, heterozygosis, dominans/recessivus
• Experimenta Pisum sativum: ratio 3:1 (F₂) pro caractere simplici

Structura – Functio Animalis

• Accommodatio structuræ ad functionem: restrictio, compromissa, proprietates emergentes
• Systemata respiratoria, digestiva, circulatoria; superficie-volumen & diffusio $J\propto A\,\Delta P$

Systemata Regulativa

Endocrinum

• Hormonae: peptidæ, steroidæ, aminæ
• Exempli: axis hypothalamo-hypophysarius-thyroideus (TRH → TSH → T₃/T₄, feedback negativus)

Nervosum

• Neuronæ, synapsis electricæ & chemicæ, potensialia actionis $V_m$; integrationes, plasticitas

Reproductio & Plantae

• Meristemata apicalia (radicis, caulis) + cambium → crescitudo primaria & secundaria
• Hormona vegetalia: auxina (elongatio), cytokinina (divisio), gibberellina (elongatio caulis, germinatio), acidum abscisicum (dormantia, stomata), ethylenum (maturatio fructuum)
• Alternantia generationum: gametophytus n (musci) vs sporophytus 2n (pteridophyta, gymnospermæ, angiospermæ)

Sexus & Evolutio

• Isogamia vs anisogamia (ovum magnum, spermium parvum)
• Dimorphismus sexualis: selectio sexualis (intra‐masculina, inter-sexus)
• Costus sexus: $50\%$ transmissionis geneticæ, dispendium energeticum

Diversitas Microbica & Virorum

• Bacteria vs Archea (pseudo-peptidoglycanum, æther-lipida)
• Virus: particulæ subcellulares (DNA vel RNA), capsida, replicationes intracellulares; mutationes altæ in virus RNA

Ecologia

Populationes

• Crescitudo exponentialis: $N(t)=N_0e^{rt}$
• Logisticum cum capacitate portandi $K$: $\frac{dN}{dt}=rN\left(1-\frac{N}{K}\right)$
• Metapopulationes: fluxus migrationis, effectus rescus, dynamica insula-continens

Communitates & Ecosystemata

• Diversitas (richness + evenness); indices Shannon $H=-\sum p<em>i\log p</em>i$
• Sucessio primaria/secondaria; disturbia, climax
• Fluxus energiæ: pyramidis trophicæ, regula $10\%$ (Lindeman)
• Cyclus aquæ, C, N, P; Gaia hypothesis (biosphæra autorregulans)

Mutatio Globalis & Crisis Biodiversitatis

• Gasorum seræ effectus: CO₂, CH₄, N₂O, CFC; incrementum >400\,ppm CO₂
• Stratum ozonis: decrementum $4\%$ per decennium
• Extinctiones: velocitas hodierna $\sim 50\,000\,species/annum$ (vs naturalis $\sim4$)
• Principia conservationis: identitas, monitio, restauratio, usus sustenabilis