Chapter Introduction How are traits passed from parents to offspring?
Heredity is the passing of traits from parent to offspring. You ......How are traits passed? •When...
Transcript of Heredity is the passing of traits from parent to offspring. You ......How are traits passed? •When...
Whatisheredity?
• Heredityisthepassingoftraitsfromparenttooffspring.
• Youinherittraitsfromyourparents
Howaretraitspassed?• Whenorganismsreproduce,traitsarepassedfromparenttooffspring.
• ThesetraitsarecarriedinDNA,thegeneticmaterial
• DNAactslikeablueprint.
publications.nigms.nih.gov
http://www.healthsystem.virginia.edu/internet/huntdisease/images/DNA.gif
Figure10.11
• ThisisaphysicalmapofthehumanXchromosome.(credit:modificationofworkbyNCBI,NIH)
• Avisibletraitormetabolicfunctionisthefinalproductofmanymolecularandbiochemicalprocesses:
• Inmostcases,informationstartswithDNAtravelingtoRNAandfinallytoprotein(ultimatelyaffectingorganismstructureandfunction).RemembertheCentralDogma?
Figure9.14
• ThecentraldogmastatesthatDNAencodesRNA,whichinturnencodesprotein.
Geneprediction
Getting to the right class…def class(animal):
""" classifies animal order by characteristics"""if hasVertebrae(animals):
if bornWithGills(animal):if developLungs(animal):
return "Amphibian"else:
return "Fish"elif warmBlooded(animal):
if hasFeathers(animal):return "Bird"
else:return "Mammal"
else:return "Reptile"
Ok.NowweidentifiedORFs.Whatisthisgoodfor?
A. DeterminetheevolutionaryoriginofgenesB. ConnectgenotypetophenotypeC. DeterminethefunctionofgenesD. LearnaboutmetabolismE. Alloftheabove
Ok.NowweidentifiedORFs.Whatisthisgoodfor?
A. DeterminetheevolutionaryoriginofgenesB. Connectgenotype tophenotypeC. Determinethefunction ofgenesD. LearnaboutmetabolismE. Alloftheabove
Wheredidanorganismcomefrom?Whatdoesanorganismlooklike?Whatdoesanorganismdo?Howdoesanorganismdoit?
Homology
AsequencedatabasesuchasGenbank couldbeusedtodoallofthefollowingEXCEPT
A)Comparecowandhumaninsulinproteinsequences.B)Predictthefunctionofanunidentifiedgenebasedonsimilargenesequences.C)Searchforgenesinafruitflythataresimilartoahumangene.D)Comparepatternsofgeneexpressionincancerousandnon-cancerouscells.
Genesà Proteins
• Proteinsà traits– Examples?
• Proteins=enzymesàmetabolism– Examples?
Figure4.11
• Metabolicpathwaysareaseriesofreactionscatalyzedbymultipleenzymes.Feedbackinhibition,wheretheendproductofthepathwayinhibitsanupstreamprocess,isanimportantregulatorymechanismincells.
Figure4.4
Genecharacteristics(GCcontent,length,codonusage,etc.)canalsotellusaboutwheregenescamefrom
Sp 1,47%GC Sp 2,38%GC
Horizontal transfer of a pathogenicity island
GC:~38%
GC:~47%
Genomic“islands”andGCcontentDue to historical horizontal transfer events, the %GC inside pathogenicity islands sometimes strongly differs from the rest of the genome.
WhichofthefollowingisanexampleofHorizontalGeneTransfer?A. Thetransmissionofaneyecolorgenefromfathertodaughter
B. Thetransmissionofageneconferringpathogenicity(theabilitytocausedisease)fromonebacterialspeciestoanother
C. Thetransmissionofageneconferringantibioticresistancefromamothercelltoitstwodaughtercells
D.Thetransmissionofatheflufromoneofyourclassmatestoyou
E. Thetransmissionofadisease-causinggenemutationfromfathertodaughter
Project1:WhatdidyoulearnabouttheSalmonellapathogenicityislandthatislinkedtoTyphoidFever?
Salmonella pathogenicity island 1
Alleles?Analleleis:
A. anotherwordforageneB. ahomozygousgenotypeC. aparticularphenotypeD. oneoftwoormorepossiblealternativeforms
ofagene
Alleles?A gene in a particular place on a particular chromosome will
express a particular trait….like flower color
Chromosome from MOM
Chromosome from DAD
Each gamete has how many alleles for a specific gene?
a. 0b. 1c. 2d. 3
DominantandRecessiveAlleles:OnetraitcanhideormaskanothertraitDominanttrait – thetraitthatalwaysshowsupwhenthealleleispresent,hidingtheothertrait
Recessivetrait – thetraitthatishiddenormaskedwheneveradominatealleleispresent
Sometraitsaredominant,somearerecessive
Mendeldiscoveredthatwhetherhispeaswereyelloworgreenisdeterminedbyasinglegeneinwhichyellow(Y)isdominantovergreen(y).Thegenotypeofyellowplantsis
A) YB) YYC) eitherYYorYyD) Yy
Figure8.12Thesepinkflowersofaheterozygotesnapdragonresultfromincompletedominance.
(credit:“storebukkebruse”/Flickr)
Bloodtypes:codominanceFigure8.13
• Ifyouwoulddescribeyourselfaswhiteorblack,yourearwaxisprobablyyellowandsticky.IfyouareEastAsianorNativeAmerican,it’slikelytobedryandwhite.
• Andforthosewiththeyellowkind,Ihatetobreakittoyou,butyourearwaxstinks.
• Don’ttakeitpersonally.Smellyearwaxisjustanotherofthegeneticquirksweinheritaspartofoneethnicgrouporanother.InnewtestsofearwaxinCaucasianandEastAsianmen,yellowearwaxfromCaucasiansgaveoffstrongerodorsthanthedry,whitekind.
• Thesamegenecontrolsbothaperson’sunderarmodorandthetypeofearwaxtheymake
AB
O
HumanABOBloodGroups
Evolutionandpopulationgenetics
• Evolutionisachangeinthecharacteristicsofapopulationoforganisms
• Behindthatphenotypicchangeisgeneticchange.
• Inpopulationgeneticterms,evolutionisdefinedasachangeinthefrequencyofanalleleinapopulation
• Allelessegregaterandomly,justlikeacoinflip,sowecanuseprobabilitytopredicttheoutcomesofgeneticcrosses(Project2)
Irisversicolor Irisvirginica Irissetosa
Traitsà species,evolutionaryrelationships