ANT 102 1st Edition Lecture 4Outline of Last Lecture I. Forces of evolutionII. VocabularyIII. Founder EffectOutline of Current Lecture I. Review of previous lecture II.DNAIII. Sexual and Asexual reproductionIV. Mendel’s Second PrincipleCurrent LectureForces of evolution was the last lecture, watched a documentaryNatural selection, mutation, gene flow and genetic drifThe four forces of evolution ^^ are they really forces?Natural selection is a result of being variable, reproducing organismsGeneric drif is a result of sampling error in allele production and successGene flow is a result of interbreedingMutation is a result of errors in DNA replicationEvolution is not so much a force, more like a result or consequenceBefore any force of evolution can take effect, mutation must occur first (it is afer all the grandfather of evolutionary forces)Natural election and genetic drif are mutually exclusive, never both, only one at a timeGenetics: DNA: a large molecule that is the ultimate source of genetic informationThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.DNA structure: DNA molecule is composed of two chains of nucleotidesNucleus: phosphate, sugar, nitrogenous baseChain is built with complimentary chain attachedA—TC—GWhat does DNA do?2 functions:Replicate itself: hydrogen bonds “unzip” and creates complimentary bondsMake proteins (protein synthesis)Protein: amino acid chains (if there is a job to be done in the molecular level, usually that job is done by a protein)Ex: hormones, enzymes, antibodies, structuralHormones: acting as messengers, regulate physiologyEnzymes: speeding up/catalyzing reactionsAntibodies: fighting foreign invadersStructural: in muscles, hair, ligaments, fingernails, lens of eyeAmino acid sequence determines protein structure and function: location specific RNA: single stranded moleculeContains a different sugar (ribose, not deoxyribonucleic acid…)Uses base URACIL instead of THYMINE A—U, not A—T intermediate between protein synthesis and DNATranscription: synthesis of mRNA for a DNA templateLook up lecture power pointTranslation: synthesis of an amino acid sequence for the mRNA templateEvery 3 mRNA bases (codon) is matched w its tRNA anti-codonGene: a sequence of DNA coding for a single trait ex. Single proteinAllele: a variation of a geneChromosomes: 23 pairs (46 total), 22 autosomes and 1 sex chromosome (XX, XY)Each gene is found is a particular location (or locus, loci plural) on a chromosomeYou have two copies of every geneEach chromosome pair called homologous pair as all the same genes, but not necessarily the dame alleleGene: same as above, plus a specific gene is found at a specific location on a chromosomeHuman body has two main cells:Somatic cellsGametes (sex)Eggs or spermReproduction of cells is accomplished through CELL DIVISION Mitosis: generating duplicate cells somanticCell division for somatic cellsResults in two identical daughter cellsDaughter cells are DIPLOID (full set of 48 chromosomes)Mitosis for gametesResults in four daughter cells which are haploid (only one of each pair of homologous chromosome (23) instead of both copies)Only one chromosome from each parent is passed to offspringMeiosis: AsexualMendelian Genetics: revisiting from a few days agoFirst principle, short and long pea crossbreedingDominant: trait expressed in a heterozygote Recessive: trait not expressed in heterozygote Codominance: expression of both in a heterozygote (HH, hh, both present in phenotype)Example:3 alleles A dominant B dominant O recessive4 phenotypes type A, B, AB, O6 genotypes AA, Ao, BB, Bo, AB(codominant), ooAre dominant alleles or recessive alleles….More frequent in a population? Better adapted to the environment? More important for individual survival?Normal?Mendel’s Second Principle:Based on his experiment breeding for two diff traits at onceDiscovered that the presence/absence of one characteristic doesn’t affect the presence of another characterIndependent assort distribution of one pair of alleles doesn’t influenceCrossing over: exchange of genetic material between homologous chromosomesImportant because recombination (production of new comb of DNA sequences caused by exchange of DNA during meiosis)Monogenic trait: trait affected by a single locus, traits are discontinuous (variations of the traits are phenomenally discrete), are actually relatively uncommonPolygenic traits: a trait affected by more than one gene—multi loci, traits are continuous (variations of trait show a range or continuum), skin color, height**vast majority of genes are polygenic Pleiotropy: a single gene affects more than one trait, ofen seen as a series of otherwise unrelated traits always appear together, the “white cat” phenomenon (cats born with all white fur, blue eyes and generally deaf)Errors in DNA replication (as long as not fatal) can be passed on to future generations—becomes a mutationMitosis: a sexual reproductionOffspring are genetically identical to parentUsually undertaken by single cell organisms, very rarely multicellular