genetics and inheritance (.ppsx)

07-Genetice (Chapters 7 & 8)

Kahoot! Get out yoursmartphone/tablet.Establish Wi-FiOpen a browserURL: http://kahoot.itTWO-member teamsUse an organism as your team name

http://kahoot.ithttp://getkahoot.com

BIO156Paradise Valley Community College#


Todays TopicsChapter 7Condensing DNASexual ReproductionHaploid vs DiploidMeiosisVariety & DiversityGenetic TermsChapter 8 The Cellular Basis of Inheritance


23/5/2017Paradise Valley Community CollegeGenetics

DNA Supercoiling

DNA Wrapping

BIO156Paradise Valley Community College#DNA Condensing & De-condensing

Source: Modified from pbs.org/newshour/updates/history-of-epigenetics-asthma. 2016.GeneGeneHard-to-read DNAEasy-to-read DNAMethylationAcetylationPhosphorylationncRNAs

DNA & Histones

BIO156Paradise Valley Community College#Mitosis

Review of MitosisSource: Pearson Education, Inc. 2017.


Source: 3dscience.com. 2015.(n)sperm

Source: 3dscience.com. 2015.(n)eggSexual ReproductionMeiosis occursonly in germ cellsof eukaryotes, forming male and female haploid gametes.Haploid (n)Having one of each chromosome characteristic of the speciesGamete Mature, haploid reproductivecell (germ cell)

Diploid (2n)Haploid (n)


BIO156Paradise Valley Community College#6


Source: popsci.com. 2017.

Source: popsci.com. 2017.4623

23Restoring Diploid NumberDiploid number (2n) is restored at fertilization.Fertilization Fusion of a sperm nucleus and an egg nucleus, results in a single-celled zygote.Zygote Diploid (2n) cell formed bygamete fusionThe first cell of a new individual,with two sets of chromosomes,one from each parent46 chromosomes(diploid)

23 chromosomes(haploid)23 chromosomes(haploid)



Meiosis

MeiosisSource: Pearson Education, Inc. 2017.

BIO156Paradise Valley Community College#MeiosisSource: Modified from Cengage. 2015.Prophase IIDIPLOIDProphase IDIPLOID

Metaphase IDIPLOID

Anaphase IDIPLOID

Telophase IDIPLOID

Random AssortmentCrossing Over23DIPLOID

1

BIO156Paradise Valley Community College#MeiosisGametesHAPLOID

Telophase IIHAPLOID

Anaphase IIDIPLOID

Metaphase IIDIPLOID

Prophase IIDIPLOIDDIPLOIDHAPLOIDSource: Modified from Cengage. 2015.

BIO156Paradise Valley Community College#Only in MeiosisMeiosis OnlyDIPLOIDHAPLOID1Random AssortmentSource: Modified from Cengage. 2015.Prophase IMetaphase IAnaphase ITelophase IProphase IIMetaphase IIAnaphase IITelophase II

Crossing Over2Gametes HAPLOID3


MeioticProphase ICrossing-over in meiosisresults in genetic diversity.Genetic Terms: Crossing-Over

Enzymes

DuplicatedPaternalChromosome

Tetrad(meiosis)

DuplicatedMaternalChromosomeNon-sisterChromatidsSisterChromatids

Synapsis

BIO156Paradise Valley Community College#Source: Modified from blogs.ancestry.com. 2017.Elizabeth1/32NativeAmerican1/16NativeAmerican1/8NativeAmericanElizabeth was 1/4Native American

Crossing-Over creates diversity

AmandaLeeLeonElizabeth Reynolds25%18372nd Great GrandparentAmanda Savage12.5%1862Great GrandparentLee George6.250%1900GrandparentLeon George3.125%1921ParentStephan George1.5625%

Note: This analysis is based uponautosomal chromosomes only.


Source: dna-explained.com. 2017.

BIO156Paradise Valley Community College#Creating diversityWilliam I of England100.0%102427th Great GrandparentGundred de Flandre50.00%106326th Great GrandparentWilliam de Warenne25.00%108725th Great GrandparentAdeline de Warenne12.50%112024th Great GrandparentWilliam mac Eanric6.25%114323rd Great GrandparentAlaxandair mac Uilliam3.13%119822nd Great GrandparentDernell Huntington1.56%121521st Great GrandparentRobert Hoo0.78%123820th Great GrandparentRosamund Hoo0.39%127819th Great GrandparentWarine Bassingbourne0.20%129818th Great GrandparentJoan Frauncis 0.10%131217th Great GrandparentWalter Reynell Sr0.05%136216th Great GrandparentWalter Reynell Jr0.02%140415th Great GrandparentRobert Reinolds0.0122%143914th Great GrandparentRobert Reynolds II0.0061%147513th Great GrandparentRobert Reynolds III0.00305%150512th Great GrandparentChristopher Reynolds Sr0.00153%153011th Great GrandparentGeorge Reynolds0.00076%155510th Great GrandparentChristopher Reynolds0.00038%16119th Great GrandparentRichard Reynolds Sr0.00019%16418th Great GrandparentRichard Reynolds Jr0.00010%16697th Great GrandparentThomas Reynolds Sr0.000048%17166th Great GrandparentThomas Reynolds Jr0.000024%17425th Great GrandparentEdward Reynolds0.000012%17784th Great GrandparentJohn Reynolds0.000006%18213rd Great GrandparentElizabeth Reynolds0.000003%18372nd Great GrandparentAmanda Jane Savage0.0000015%1862Great GrandparentLee Andrew George0.0000007%1900GrandparentLeon George0.0000004%1921ParentStephan George0.0000002%

Duke of NormandyWilliam the Bastard1066 The Battle of HastingsWilliam the ConquerorKing William I of England(1024-1087)

Do you recognize this guy?

BIO156Paradise Valley Community College#Genetic Terms

Homozygous genesHeterozygous genesHomologousChromosomesHomologousChromosomesAlleles

Genes

BIO156Paradise Valley Community College#Dominant and Recessive AllelesDominantRefers to an allele (written as upper case) that masks the effect of a recessive allele paired with it (written as lower case)Recessive Refers to an allele with an effect that is masked by a dominant allele paired with it

RecessiveDominant



GenotypeAn individuals alleles constitute genotype.Heterozygotes (hybrids) have two non-identical alleles. Hybrid The offspring of a crossbetween two individualsthat breed true for differentforms of a trait.

Homozygote(hybrid)AABB

Heterozygote(hybrid)bAaBDihybrid

Monohybrid



Random Segregation

GametesMetaphase IISource: Modified from Cengage. 2015.Anaphase II

Homologous chromosomes move apart during meiosis, separating the pairs of genes they carry.Each gamete carriesonly one of the twomembers of eachgene pair.All gametes of a homozygous parent have the same allelesfor a trait.




Gene Segregation (Homozygote)Zygote (2n)

Meiosis IIMeiosis IDNA replication (S phase)Germ cells (2n)Gametes (n)Gametes (n)spermatogonium oogonium


Variety & Diversity


Todays TopicsChapter 8Gregor MendelPunnett SquaresLaws of InheritanceExtensions of the Laws of InheritanceNon-Mendelian GeneticsGenetic Disorders

BIO156Paradise Valley Community College#Gregor Mendel

Source: climbers.lsa.umich.edu. 2017.Male (stamen) and female (pistil) germ cells are protected, preventing cross-pollination.

Why did Mendel use pea plants?

Source: The McGraw-Hill Companies, Inc. 2017.1822-1884

BIO156Paradise Valley Community College#Why Did Mendel Use Pea Plants?Source: Modified from biotechlearn.org.nz. 2017.

Pistol: ova (female)Enclosing petalStamen: pollen (male)

Manual Cross-PollinationRemoveStamenCollectPollenDeposit pollen from #1

Purple PeaPlantWhite PeaPlant #1

White Pea #2

BIO156Paradise Valley Community College#Mendelian Inheritance PatternsDominant/recessive relationships among the alleles can be reveled by a monohybrid cross between heterozygous individuals.Monohybrid cross Cross in which individualswith different alleles of asingle gene are crossed.Dominant : Recessive

Heterozygote(hybrid)AaMonohybridAaAaAaaaPunnett Square3:1



AAPunnett Squares: A Monohybrid CrossHeterozygousparentPurplePurplePurpleWhite

Heterozygousparent

AaAaPossibleOffspringphenotypesPossibleOffspringgenotypesAA3:1AaAaaameiosismeiosisgametesgameteszygotes

BIO156Paradise Valley Community College#26Figure 9.5: Animated!Example of a monohybrid cross. Figure It Out: How many genotypes are possible among the offspring of this cross?Answer: Three: AA, Aa, and aa.3/5/2017Paradise Valley Community CollegeGenetics

Tt

ttTMonohybrid CrossesF1 Zygotes (2n)Breeding True

TT

tt

Parentstttt

TtParentsF2 Gametes (n)TTttTTTtt

F2 Zygotes (2n)TTTT

F1 Gametes (n)tTtTtTtTtTTttTtTtbothhomozygous


Chromosome 4: Red Hair ColorJeannies genotype is bb. (Homozygous)Lees genotype is Bb. (Heterozygous)

BIO156Paradise Valley Community College#bbBbbbBb

A Monohybrid Cross for Red HairHomozygous parentHeterozygous parentOffspring phenotype

BbbbBbbb


A Monohybrid Cross for Red HairWhy did this not work out to 50-50?Definition of Prediction : The act of making an educated guess

Oops!But they did getsomething right...

XXXYXXXYX YXX


Monohybrid & Dihybrid Crosses

F2?Dihybrid Cross(Two traits studied)Monohybrid Cross(One trait studied)


Independent AssortmentInheritance of one trait does not affect inheritance of other traits. The Rule of Independent Assortment Genes for different traits can segregate independently duringthe formation of gametes.A dihybrid crossillustrates this rule.Experiment in whichindividuals with differentalleles of two genes arecrossed

Source: imgarcade.com. 2015.




ryryRYRyrYryRRYYRrYyrrYyRryyRrYyRrYYRRYyRrYyRrYYRrYyRRYyRRyyRryyrrYYrrYyrryy

RYRyrYryRYDihybrid CrosszygotesRYRYRyrYry

RRYY

rryyF2F19:3:3:1

Parentsgametes

Source: slideplayer.com. 2017.Pisum sativum, chromosome #116151413121110987654321

1, 2, 3, 4, 5, 7, 9, 10, 13 (9)

6, 8, 14 (3)

11, 12, 15 (3)

16 (1)

BIO156Paradise Valley Community College#Non-Mendelian GeneticsAn allele may befully dominant, co-dominant, or incompletely dominant.Co-dominanceTwo alleles that are both fullyexpressed in heterozygous individualsIncomplete dominanceOne allele is not fully dominant overanother, so the heterozygous phenotypeis between the two homozygousphenotypes.



Co-Dominance (Non-Mendelian)Genotypes:AABBO

Phenotypic blood types

BIO156Paradise Valley Community College#35Figure 9.9: Animated!Combinations of alleles that are the basis of blood type.3/5/2017Paradise Valley Community CollegeGenetics

Source: ghr.nlm.nih.gov. 2015.

ISCN Numbering begins at the centromere.The centromere defines a long (q) and a short (p) arm.Chromosome number appears first.Arm designator appears next.Bands and sub-bands are designated by morphological features, numbered from the centromere.How to Read an Chromosomal Ideogramcentromereshortarm (p)longarm (q)9q34.2Long arm of chromosome #9 at band three, sub-band four, sub-sub-band two


Source: Modified from classes.midlandstech.edu. 2015.Source: ghr.nlm.nih.gov. 2015.

ABO Blood TypingThe DNA of the alleles at 9q34.2 is translated equally into mRNA.The mRNA produces enzymes that create both A & B antigens.Antigens coat the surface of the red blood cell.

Both AntigensNo AntigensAntigen AAntigen BABABO

UniversalRecipientUniversalDonor


BIO156Paradise Valley Community College#37Figure 9.9: Animated!Combinations of alleles that are the basis of blood type.3/5/2017Paradise Valley Community CollegeGenetics

ABO Blood Typing & The Rhesus FactorEmbryo inherits fathers Rh+Rh+ enters mothers bloodstream.Pregnancy is nominal.Mother is sensitizedantibodies form.Second pregnancy: Mothers antibodies attack fetal blood cells.

Erythroblastosis fetalis can be prevented by antenatal injections of IgG anti-D antibodies.


BIO156Paradise Valley Community College#Incomplete Dominance

XSnapdragonAntirrhinum majusR Rr r

BIO156Paradise Valley Community College#39Figure 9.10Incomplete dominance of flower color alleles in snapdragon plants. Figure It Out: Is the experiment in (B) a monohybrid or dihybrid cross? Answer: A monohybrid cross.3/5/2017Paradise Valley Community CollegeGenetics

EpistasisSome traits are affected by multiple gene products, an effect called polygenic inheritance or epistasis.B = blackb = chocolateE = causes expressionof coat colore = prevents expressionof coat color

BBEE BbEEBBEe BbEebbEEbbEeBBeeBbee bbee



Polygenic PhenotypesEye Color VariationPigmentation of the iris varies from light brown to black, depending on the concentration of melanin.There may be16 genes involved.


BIO156Paradise Valley Community College#Source: uic.edu. 2015.Multifactorial InheritanceContinuous Variation A range of small differences in a shared traitHuman Height253,288 people434 gene regions697 bp variants

Not based on journal data. Illustration only.

505660Bell curvedistribution


BIO156Paradise Valley Community College#Pleiotropymore + waysPleiotropic genes influence two or more traits.Mutations in pleiotropicgenes are associatedwith PKUsickle cell anemiacystic fibrosisMarfan syndrome

Marfan syndromeSource: modified from nasagap.com. 2015




Environmental Effects on PhenotypeLepus americanus, the Snowshoe hareDuring summermonths the coatis brown.During winter months,the rabbits coat iswhite.What can affect and contribute to variation in phenotypes?MutationsInteractions among genesEnvironmental conditions

Source: modified from skolaiimages.com. 2015.

Source: skolaiimages.com. 2015.


BIO156Paradise Valley Community College#44Figure 9.13Environmental effects on animal phenotype. The color of the snowshoe hares fur varies by season: (A) summer, and (B) winter. Both forms offer seasonally appropriate camouflage from predators. (C) The body form of the Daphnia at the left develops in environments with few predators. A longer tail spine and a pointy head (right) develop in response to chemicals emitted by predatory insects.3/5/2017Paradise Valley Community CollegeGenetics

Human Genetic AnalysisInheritance patterns in humans are studied byfollowing inherited genetic disorders through generations.Graph results in a pedigree. Pedigree Chart showsthe pattern ofinheritanceof a genein a family

aaAaAaAaaaAaAaAaAaAaAaaaAaAaaffectedunaffectedaffectedaffected

BIO156Paradise Valley Community College#Genetic Abnormalities and DisordersGenetic abnormalityUncommon version of a heritable trait that does not result in medical problems Genetic disorderHeritable condition that results in a syndrome of mild to severe medical problemsSyndrome Set of symptoms characterizing a genetic disorder

BIO156Paradise Valley Community College#Human Genetic DisordersSome dominant or recessive alleles on autosomes or the X chromosome are associated with genetic abnormalities or disorders.An autosomal dominant allele is expressed in both homozygotes and heterozygotes.An autosomalrecessive alleleis expressed onlyin homozygotes.

Source: galleryhip.com. 2015.

BIO156Paradise Valley Community College#Some Autosomal Dominant DisordersDisorder/AbnormalityMain SymptomsProgeriaDrastic, premature aging *AchondroplasiaDwarfismCamptodactylyRigid, bent fingersHypercholestrolemiaHigh cholesterol levelsHuntingtons diseaseNeural system degenerationMarfan syndromeAbnormal connective tissuePolydactylyExtra fingers and/or toesNeurofibromatosisTumors of nerves and skin

BIO156Paradise Valley Community College#Some Autosomal Recessive DisordersDisorder/AbnormalityMain SymptomsAlbinismAbsence of pigmentation *MethemoglobinemiaBlue skin colorationCystic fibrosisAbnormal mucus secretionsEllis-van Creveld SyndromeDwarfism, heart defectsFanconi anemiaBone marrow failureGalactosemiaBrain, liver, and eye damagePhenylketonuria (PKU)Mental impairmentSickle-cell anemiaAdverse pleiotropic effects

BIO156Paradise Valley Community College#Autosomal InheritanceProgeria (dominant)Albinism (recessive)

Source: pennlive.com. 2015.

Source: thinglink.com. 2015.

BIO156Paradise Valley Community College#Some X-Linked Recessive DisordersDisorder/AbnormalityMain SymptomsAISMale with female traitsColor blindnessInability to distinguishFragile X SyndromeMental impairmentHemophiliaImpaired blood clotting *Muscular dystrophiesProgressive loss of functionHunter SyndromeJoint, retinal, & retardation

BIO156Paradise Valley Community College#X-Linked Recessive Disorders

Males cannot transmit a recessive X-linked allele to their sons.Females pass X-linked alleles to male offspring.XhYXhYXHYXHXhXHYXHXhXhYXHYXHYXHXhXHYXHXh

XYXXXH or Xh XhXH alleles

XHYXHXhAlleles on the X chromosome are inherited and expressed differently in males and females.

BIO156Paradise Valley Community College#Types of Color Blindness

Monochromancy (total color blindness)

Tritanopia (blue-yellow blindness)

Deuteranopia (red-green blindness)

NormalSource: Q-lieb-in, commons.wikimedia.org. 2017.

BIO156Paradise Valley Community College#Red-Green Color BlindnessNormal orFemale carrierAbnormalSource: huffingtonpost.com. 2015.

Source: huffingtonpost.com. 2015.

Source: huffingtonpost.com. 2015.XBXbCarrier FemaleXbXbColor-blind FemaleXBYNormal MaleXbYColor-blind MaleBoth male & female are susceptible.

BIO156Paradise Valley Community College#54Figure 9.18: Animated!X-linked recessive inheritance. Above, in this example, the mother carries a recessive allele on one of her X chromosomes (red). Right, color blindness in inherited in an X-linked recessive pattern. (A) View with redgreen color blindness. The perception of blues and yellows is normal, but red and green appear similar. (B) Compare what a person with normal vision sees. Far right, two Ishihara plates, which are standardized tests for color blindness. (C) You may have one form of redgreen color blindness if you see the number 7 instead of 29 in this circle. (D) You may have another form if you see a 3 instead of an 8.3/5/2017Paradise Valley Community CollegeGenetics

Color BlindnessSource: www.glaucoma-surgery.info. 2015.Ready

Ishihara Color Test PlateWrite down the numbers you see.Actual numbers: 74, 7, 4274 21 .........red/green color blindness7 no # .....color blind42 faint 2 protanopiafaint 4 deuteranopia


BIO156Paradise Valley Community College#55Figure 9.18: Animated!X-linked recessive inheritance. Above, in this example, the mother carries a recessive allele on one of her X chromosomes (red). Right, color blindness in inherited in an X-linked recessive pattern. (A) View with redgreen color blindness. The perception of blues and yellows is normal, but red and green appear similar. (B) Compare what a person with normal vision sees. Far right, two Ishihara plates, which are standardized tests for color blindness. (C) You may have one form of redgreen color blindness if you see the number 7 instead of 29 in this circle. (D) You may have another form if you see a 3 instead of an 8.3/5/2017Paradise Valley Community CollegeGenetics

Changes in Chromosome NumberChromosome number can change permanently, usually resulting from non-disjunction from which arises aneuploidy.Non-disjunction Failure of chromosomes toseparate during meiosisAneuploidy Cell has too many or too fewcopies of a particularchromosome(trisomy, monosomy)

Source: Modified from Cengage. 2015.


BIO156Paradise Valley Community College#Aneuploidy: Trisomy 13 & Trisomy 18

Source: ourmed.org. 2015.

19876543210X1817162215142120191211Y13

19876543210X1716221514212019131211Y18Source; medgen.genetics.utah.edu. 2015.

AN = Greek, notEU = Greek, trueploidy = set of chromosomes

Trisomy 13 Patau SyndromeMental retardation & motor disorderMicrocephalyPolydactylyLife expectancy: 1 yearTrisomy 18Edwards SyndromeMicrocephalyCleft lip/cleft palateLife expectancy: 5-15 days

BIO156Paradise Valley Community College#Aneuploidy: Monosomy XMonsomy X (Turner Syndrome)Only non-fatal monosomyShort stature, swellingBroad chest, low hairlineLow-set ears, webbed necksAmenorrhea & sterilityCongenital heart diseaseHypothyroidism Diabetes, vision & hearing concerns

18765432X171622151421201913Y189101211

Source: en.wikipedia.org. 2017.

Source: en.wikipedia.org. 2017.



Autosomal Change & Down SyndromeTrisomy 21 (Down syndrome)The only autosomal trisomy that allows humans to survive to adulthoodAffected individuals tendto have certain physicalfeatures and impairments.Non-disjunction leading totrisomy 21 increases withage of the mother.

YX22212019181716151413121110987654321


BIO156Paradise Valley Community College#Aneuploidy: Tetrasomy 18pTetrasomy 18p1 in 140,000 live birthsPatent ductus arteriosus most commonCardiac anomalies Cryptorchidism (testicles absent)Hip dysplasia (hip dislocation)Horseshoe kidney

X22212019Y187654321716151413189101211




genetics and inheritance (.ppsx)

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