Aice Biology Nuclear Division

11/9/2011 AICEBiology Ch6JonesCh10RavenContent Replicationandsectionalisationofnucleiand carrellular telephones Understandingofchromo roughlybehaviorinmitosis trainingOutcomes Candidatesshouldbeableto (a) explicatetheimportanceofmitosisintheproductionofgenetic ally identical mobile phones,growth, neuteringandasexual duplicate (b)PAdescribe,withtheaidofdiagrams,thebehaviorof ( ) chromosomesduringthemitoticcell oscillationandtheassociated behaviorofthenuclear envelope,cellmembrane,centrioles and spindle(namesofthemainstages beexpected) (c)explainhowuncontrolledcell fragmentcanresultin crabby personand identify grammatical constituentsthatcanincreasethechancesofcancerousgrowth (d)explainthemeaningsofthetermshaploidanddiploidandtheneedfor areduction subdivision( myosis)priortofertilizationinsexual reproduction (e)usethe familiaritygainedinthissectionin brand-newsituationsortosolve connectproblems. ? Multicellular organismsbeginasasinglecell ? Mitosis ? cadredivision ? Alsousedinrep air ? Asexualreproduction p Cell Size ? Bacteria ? E. Colidoublesevery30minutes ? Heart&nervoussystemcellsrarelydivide,ifatall ? Skincellsanddigestivetractcellsdividethroughoutlife ? several(prenominal)(prenominal)every6hours ? Growtoa indisputablesizeand immobilize ? Controlsareturnedonandoff ? Duringinjury,cellsarestimulatedand promptlydivideandgrow producesnewcells,. i. e. ealing ? Afterhealing,cellgrowthslowsandreturnsto approach pattern ? Uncontrolledcellgrowthresultsincancer Surface rural area (length x width x 6) Volume (length x width x height) Ratio of Surface Area to Volume ? Surfaceareaand mountaindonotincreaseatthesamerate ? biggercellshavedifficultyexchangingoxygenandwastein andoutofthecell ? Beforecellbecomestoolargeitundergoescellulardivision and homunculuss2 girlfriendcells 1 11/9/2011 Cell Cycle includes G1 kind 2Gphases andSphase makeup Interphase Interphase M phase (Mitosis) M phase Sphase is shared out into is divided into G1 phase S phase G2 phase Prophase MetaphaseAnaphase Telophase G2 phase Thecellhasseveralsystemsforinterruptingthecellcycle ifsomethinggoeswrong ? Checkpointat expiryofSphase ? MonitorforpresenceofOkazakifragmentsonlagging brink during restitution ? Cellisnotpermittedtoproceedinthecellcycleuntilfragments ? DNAOverload ? mustbeenoughDNA satisfyinginthenucleus ? Largerthecell=informationcrisis ? Materialsmustbeabletopassthroughthe aregone cytoplasm chop-chop ? Speedisdeterminedbysizeofcell ? Rateatwhichfoodandoxygenareusedis ? DNADamagecheckpoints ? mavenDNA abusebeforecellentersSphase(G1 checkpoint) ? DuringSphase ?Read also Lab 2 BiologyAfterDNA heel counteratG2 checkpoint ? SpindleCheckpoints ? get windanyfailureofspindlefibers ? Detectimproperalignmentofspindleitselfandblock cytokinesis ? Triggerapoptosisifdamageisirreparable determinedbyvolume ? Volumeincreasesfasterthan outareaas cellssizeincreases ? CellsDNAnolongerabletoservetheincreasing ineluctablyofthegrowingcell ? Cellsconstantly divide ? Deadcellsrepla ced bynewcells ? malignant neoplastic disease ? mistakeincell cycle ? cancerouscells formtumors (massesoftissue) ? tumorsdeprive normalcellsof nutrients 2 11/9/2011 ? Mutagen ? Afactorthatbringsaboutamutation ? Genetic ? Mutations ? Oncogene Carcinogen ? Any componentthatcausescancer ? Somefactorswhichcanincreasemutationrates,thus promotingcancer ? IonizingRadiationXrays,gammaraysparticlesfrom ? Environmental ? cigarettesmoke ? airand piddlepollution ? UVradiationfromthesun ? viralinfections ? Carcinogen ? Any center fieldthatcaninduceorpromotecancer ? Mostcarcinogensaremutagens(changeingenes) radioactivedecay? breakdownofDNAstrands ? Chemicalstobaccosmoke,certaindyes ? VirusInfectionLymphoma,Papilloma viruses ? Hereditarypredisposition genetic amour ? BenignTumors(tumours) ? Donotspreadfromtheirsiteoforigin thocancompress nddisplacesurroundingtissues ? Warts,ovariancysts,somebraintumors ? Malignant ? Cancerous ? Dangerousandspreadthroughoutthe organic structure ? Invadeformer(a)tis suesanddestroythem ? Healthy ? Cancer yellow espy ? Stagingisimportanttodetermineifthepatientis potentiallyinacurableearlystageorotherwise ? compass point0? CancerinSitu ? formatI? Cancerislessthan2cm. ? StageII? Cancerisbetween2to5cmwithorwithout involvementoftheglandsinthearmpit i l f h l d i h i ? StageIII? Cancerislargerthan5cmor thereisextensive involvementoftheglandsinthearmpit ? StageIV? Cancerhasspreadoutsidethebreastand nvolvesotherorgansinthe system Causeof1outof17deathsinBritainin1990 1in13deathsinmen1in27deathsinwomen ? StageI&IIareconsideredearlyandcurable. ? StageIVdiseaseisnotcurable. 3 11/9/2011 ? Chromosome ? bothidenticalhalves connectedtogetherbya centromere ? Ch Chromatid tid ? halfofonechromosome ? Containsonecompleteset ofinformation ? Copiesitselftomakethe otherchromatid Centromere Twochromatids,eachmadeof identicalDNAmolecules ? Thekaryotype ofanormal humanfemale contains23 pairsofhomologous chromosomes ? 22pairsofautosomes ? 1pairofXchromosomes ? The karyotype ofanormal umanmale contains ? thesame22pairsofautosomes ? UncoiledDNAcalledchromatin? betweencelldivisions ? Happensduringcelldivision ? DNAwrapstightlyaroundproteinscalledhistones ? oneXchromosome ? oneYchromosome 4 11/9/2011 Sex chromosomes Spindle forming Centrioles Nuclear envelope Chromatin Centromere Chromosomes (paired chromatids) Centriole Interphase Cytokinesis Telophase Nuclear envelope reforming Prophase p Spindle Centriole soulfulness chromosomes Metaphase Anaphase ? girlfriendcellsgeneticallyidenticaltoparentnucleus ? Replacement/repairoftissues ? Skin ? Liningofgut A sample of cytoplasm is remote from a cell in mitosis.The sample is injected into a consequence cell in G2 of interphase. ? Basisofasexual reproduction As a result, the second cell enters mitosis. Cyclinsregulatethetimingofthecellcyclein eucaryoticcells 5 11/9/2011 Golgi apparatus produces vesicles ? haploid(n)anddiploid(2n)chromosomes Twochromatids,eachmadeof identicalDNAmolecules Centromere ? reductiondivision(meiosis)priortofertilizationinsexual reproduction Chapter17Meiosis, geneticsandgenecontrolgoesinto moredetail Geneticvariation trackoverin ProphaseI 6 11/9/2011 maternalistic set of chromosomes Possibility 1 Paternal set of chromosomes Possibility 2Two evenly probable arrangements of chromosomes at metaphase I Metaphase II Prophase II Metaphase II Anaphase II Telophase II Meiosis II results in four haploid (N) daughter cells. Meiosis I results in two The chromosomes line up in a The sister chromatids haploid (N) daughter cells, similar way to the metaphase crystallize and move toward each with half the number of stage of mitosis. opposite ends of the cell. chromosomes as the original. Daughter cells Combination 1 Combination 2 Combination 3 Combination 4 Prophase I of meiosis Nonsister chromatids MITOSIS Parent cell (before chromosome replication) reduction division Chiasma (site of crossing over) MEIOSIS I ProphaseProphase I Chromosome replication Chromosom e replication 2n = 6 Tetrad Duplicated chromosome (two sister chromatids) Chiasma, site of crossing over Metaphase I Tetrad formed by synapsis of homologous chromosomes Metaphase Chromosomes positioned at the metaphase plate Tetrads positioned at the metaphase plate Metaphase I Metaphase II Anaphase Telophase Sister chromatids separate during anaphase Homologues separate during anaphase I sister chromatids remain together Anaphase I Telophase I Haploid n=3 Daughter cells of meiosis I MEIOSIS II Daughter cells 2n Daughter cells of mitosis 2n n n n n Daughter cells of meiosis II Recombinant chromosomes Sister chromatids separate during anaphase IIGeneral Biology Ii Study fly the coop (Online Class)