Genetics Yeah-ya! -You need an individual whiteboard for you and a big whiteboard for your group.

GeneticsGenetics

Yeah-ya!Yeah-ya!

-You need an individual -You need an individual whiteboard for you and a big whiteboard for you and a big

whiteboard for your groupwhiteboard for your group

PRACTICEPRACTICE

E = Free ear lobes E = Free ear lobes

e = attached ear lobese = attached ear lobes

Cross a heterozygous free-eared male with Cross a heterozygous free-eared male with a woman with attached ear lobesa woman with attached ear lobes

eeee

EeEe

e e

e

E

Genotypic Ratio : 2:2EE – 0

Ee – 2 (50%)Ee – 2 (50%)

Phenotypic Ratio : 2:2Free – 2 (50%)

Attached – 2 (50%)

ee

Ee

e

e

E

Draw the other possible crosses for Draw the other possible crosses for this genethis gene

Use other possible genotypesUse other possible genotypes

Punnett Square TrendsPunnett Square Trends

What process is a punnett square What process is a punnett square showing (predicting)?showing (predicting)?

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EeEe EeEe

EeEe EeEe

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Geno – 4:0Pheno – 4:0



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EeEe eeee

EeEe eeee

EeEe eeee

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Geno – 2:2Pheno – 4:0 Geno – 2:2

Pheno – 2:2

Geno – 1:2:1Pheno – 3:1

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EeEe

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EeEe eeee

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Geno – 1:1Pheno – 2:0 Geno – 1:1

Pheno – 1:1

Geno – 1:2:1Pheno – 3:1

Independent vs. Dependent Independent vs. Dependent AssortmentAssortment

It’s all about ProbabilityIt’s all about Probability

Old School ThinkingOld School Thinking

MendelMendel

Why Peas?Why Peas?

•Chosen for its 7 Chosen for its 7 easily easily distinguishable distinguishable characteristicscharacteristics•Short life spanShort life span•SmallSmall•Large number Large number of offspringof offspring•Easy to self or Easy to self or cross fertilizecross fertilize

Mendel’s ProcessMendel’s Process

4 Key Findings4 Key Findings

Characters (traits) are influenced by Characters (traits) are influenced by allelesalleles (different forms of the same gene) (different forms of the same gene)

Each organism inherits 2 “factors” (alleles) Each organism inherits 2 “factors” (alleles) for each trait – one from each parentfor each trait – one from each parent

One allele will dominate over the recessive One allele will dominate over the recessive oneone

Alleles segregate during gamete Alleles segregate during gamete productionproduction

SEED SHAPE

SEED COLOR

CHROMOSOMESCHROMOSOMES

LETTERS are ALLELES

THREE DIFFERENT POSSIBILITIES FOR A GENE

HOMOZYGOUS

DOMINANT

HOMOZYGOUS

RECESSIVE

HETEROZYGOUS

DOMINANT

MEIOSISMEIOSIS

4 CELLS WITH ‘R’ ALLELE FOR THIS GENE

How did Mendel find true-breeding How did Mendel find true-breeding plants?plants?

Any ideasAny ideas

TestcrossTestcross

What does it mean to be dominant?What does it mean to be dominant?

Different types of inheritanceDifferent types of inheritance

Complete DominanceComplete Dominance – 50 copies of the – 50 copies of the functional protein functional protein gives the same effect gives the same effect as 100 copies as 100 copies ((haplosufficiencyhaplosufficiency))– PKUPKU (genetic disorder (genetic disorder

where phenylalanine where phenylalanine cannot be broken cannot be broken down – missing down – missing enzyme)enzyme)

Can cause mental Can cause mental retardation if untreatedretardation if untreated

Incomplete Dominance – 50 copies is not Incomplete Dominance – 50 copies is not sufficient (Flower color in snapdragons)sufficient (Flower color in snapdragons)– FF – produces 100 red pigment molecules FF – produces 100 red pigment molecules

(very dense) – seen as red(very dense) – seen as red– Ff – produces 50 red pigment molecules (less Ff – produces 50 red pigment molecules (less

dense) – seen as pinkdense) – seen as pink– ff – produces no red pigment molecules – ff – produces no red pigment molecules –

seen as whiteseen as white

What you should knowWhat you should know

Homozygous/HeterozygousHomozygous/HeterozygousGenotype/PhenotypeGenotype/PhenotypeDominant/RecessiveDominant/RecessiveAlleleAllelePunnett SquarePunnett SquareComplete/Incomplete/CodominanceComplete/Incomplete/CodominanceBlood TypesBlood TypesSex-linked GenesSex-linked Genes

Codominance – 2 different proteins can be Codominance – 2 different proteins can be made by a single gene (A&B blood types)made by a single gene (A&B blood types)– When the A allele is present – A antigens are When the A allele is present – A antigens are

made and seen on the RBC surfacemade and seen on the RBC surface– When the B allele is present – B antigens are When the B allele is present – B antigens are

made and seen on the RBC surfacemade and seen on the RBC surface– When neither are present – no antigens are When neither are present – no antigens are

presentpresent– When both alleles are present – both antigens When both alleles are present – both antigens

are seen on the surface of the RBC’sare seen on the surface of the RBC’s

Multiple Alleles – more than 2 Multiple Alleles – more than 2 possible alleles for a genepossible alleles for a gene

Rh Factor – normal autosomal Rh Factor – normal autosomal inheritanceinheritance

Blood Types and PersonalityBlood Types and PersonalityAccording to the Japanese...According to the Japanese...

Type OType OYou want to be a leader, and when you see You want to be a leader, and when you see something you want, you keep striving until you achieve something you want, you keep striving until you achieve your goal. You are a trendsetter, loyal, passionate, and your goal. You are a trendsetter, loyal, passionate, and self-confident. Your weaknesses include vanity and self-confident. Your weaknesses include vanity and jealously and a tendency to be too competitive.jealously and a tendency to be too competitive.Type AType AYou like harmony, peace and organization. You You like harmony, peace and organization. You work well with others, and are sensitive, patient and work well with others, and are sensitive, patient and affectionate. Among your weaknesses are stubbornness affectionate. Among your weaknesses are stubbornness and an inability to relax.and an inability to relax.Type BType BYou're a rugged individualist, who's straight You're a rugged individualist, who's straight forward and likes to do things your own way. Creative forward and likes to do things your own way. Creative and flexible, you adapt easily to any situation. But your and flexible, you adapt easily to any situation. But your insistence on being independent can sometimes go too insistence on being independent can sometimes go too far and become a weakness.far and become a weakness.Type ABType ABCool and controlled, you're generally well-liked Cool and controlled, you're generally well-liked and always put people at ease. You're a natural and always put people at ease. You're a natural entertainer who's tactful and fair. But you're standoffish, entertainer who's tactful and fair. But you're standoffish, blunt, and have difficulty making decisions.blunt, and have difficulty making decisions.

TodayToday

Have outHave out– ch. 14 reading guidech. 14 reading guide– Incomplete WSIncomplete WS– Blood Type WSBlood Type WS

Couple other thoughts on blood Couple other thoughts on blood typestypes

Rh+ can receive Rh- blood, but Rh- Rh+ can receive Rh- blood, but Rh- cannot receive Rh+ blood (negative cannot receive Rh+ blood (negative person’s immune system attacks the Rh person’s immune system attacks the Rh factor present in the + blood)factor present in the + blood)

When a person with A blood receives O When a person with A blood receives O blood, the anti-A and anti-B molecules that blood, the anti-A and anti-B molecules that are received from the O blood are not at a are received from the O blood are not at a high enough concentration to affect the high enough concentration to affect the person with A bloodperson with A blood

Other inheritance patternsOther inheritance patterns

Need to knowNeed to know– The definition of the wordsThe definition of the words– An example seen in natureAn example seen in nature

EpistasisEpistasis

When 2 or more genes control 1 When 2 or more genes control 1 phenotype (gene-gene interactions)phenotype (gene-gene interactions)

Remember – normal dihybrid cross of 2 Remember – normal dihybrid cross of 2 heterozygotes give you a 9:3:3:1 heterozygotes give you a 9:3:3:1 phenotypic ratiophenotypic ratio

If 2 genes show epistasis, this ratio can If 2 genes show epistasis, this ratio can changechange

ExamplesExamplesKernel Color in wheatKernel Color in wheatIf 1 allele of gene A or If 1 allele of gene A or gene B is dominant, the gene B is dominant, the wheat is coloredwheat is coloredThe only individual that is The only individual that is white is aabbwhite is aabbRatio 15:1 when 2 Ratio 15:1 when 2 dihybrids are crossed dihybrids are crossed (usually a 9:3:3:1 ratio)(usually a 9:3:3:1 ratio)This does not change This does not change how the Punnett square how the Punnett square is set-up but rather how it is set-up but rather how it is interpretedis interpreted

Flower color in sweet peaFlower color in sweet pea

Both genes need a Both genes need a dominant (functional) dominant (functional) allele to create allele to create anthocyanin (color)anthocyanin (color)

Ratio is 9:7Ratio is 9:7

Albinism in miceAlbinism in mice

B gene – determines if mice pigment color B gene – determines if mice pigment color is brown or blackis brown or black

C gene – determines if any pigment is C gene – determines if any pigment is present at allpresent at all

Creates a 9:3:4Creates a 9:3:4

PleiotropyPleiotropyWhen 1 gene has multiple phenotypic effectsWhen 1 gene has multiple phenotypic effects

ExamplesExamples– Vestigial wing gene also causes changes in the Vestigial wing gene also causes changes in the

balancers, the direction of bristles, and the number of balancers, the direction of bristles, and the number of eggs in the ovarieseggs in the ovaries

– GAPDH – 1GAPDH – 1stst known for the metabolism of glucose, known for the metabolism of glucose, also known for the regulation of protein translation, also known for the regulation of protein translation, aiding in the transport of RNA to cytoplasm, aiding in aiding in the transport of RNA to cytoplasm, aiding in DNA repair and DNA replicationDNA repair and DNA replication

– Diseases such as sickle-cell anemia are caused by a Diseases such as sickle-cell anemia are caused by a mutation at 1 gene yet have multiple phenotypic mutation at 1 gene yet have multiple phenotypic consequencesconsequences

Polygenic (quantitative) TraitsPolygenic (quantitative) Traits

When multiple genes aid in the expression When multiple genes aid in the expression of a single traitof a single trait

Examples – height, coloration (skin color, Examples – height, coloration (skin color, eye color)eye color)

AssumptionsAssumptions– Effects of each gene is additiveEffects of each gene is additive– No dominance (incomplete dominance)No dominance (incomplete dominance)– No linkageNo linkage

Plant Height in Tobacco PlantsPlant Height in Tobacco Plants

7 classes of height – 0 to 6 (depending on 7 classes of height – 0 to 6 (depending on number of dominant alleles the plant has number of dominant alleles the plant has at 3 separate genes (A, B, and C)at 3 separate genes (A, B, and C)AABBCC (6) x aabbcc (0) yields all AABBCC (6) x aabbcc (0) yields all intermediate (3) heterozygotes AaBbCcintermediate (3) heterozygotes AaBbCcLet’s look at the F1 crossLet’s look at the F1 cross– AaBbCc x AaBbCcAaBbCc x AaBbCc

ABCABC ABcABc AbCAbC aBCaBC AbcAbc abCabC aBcaBc abcabc

ABCABC AABBCCAABBCC AABBCcAABBCc AABbCCAABbCC AaBBCCAaBBCC AABbCcAABbCc AaBbCCAaBbCC AaBBCcAaBBCc AaBbCcAaBbCc

ABcABc AABBCcAABBCc AABBccAABBcc AABbCcAABbCc AaBBCcAaBBCc AABbccAABbcc AaBbCcAaBbCc AaBBccAaBBcc AaBbccAaBbcc

AbCAbC AABbCCAABbCC AABbCcAABbCc AAbbCCAAbbCC AaBbCCAaBbCC AAbbCcAAbbCc AabbCCAabbCC AaBbCcAaBbCc AabbCcAabbCc

aBCaBC AaBBCCAaBBCC AaBBCcAaBBCc AaBbCCAaBbCC aaBBCCaaBBCC AaBbCcAaBbCc aaBbCCaaBbCC aaBBCcaaBBCc aaBbCcaaBbCc

AbcAbc AABbCcAABbCc AABbccAABbcc AAbbCcAAbbCc AaBbCcAaBbCc AAbbccAAbbcc AabbCcAabbCc AaBbccAaBbcc AabbccAabbcc

abCabC AaBbCcAaBbCc AaBbCcAaBbCc AabbCCAabbCC aaBbCCaaBbCC AabbCcAabbCc aabbCCaabbCC aaBbCcaaBbCc aabbCcaabbCc

aBcaBc AaBBCcAaBBCc AaBBccAaBBcc AaBbCcAaBbCc aaBBCcaaBBCc AaBbccAaBbcc aaBbCcaaBbCc aaBBccaaBBcc aaBbccaaBbcc

abcabc AaBbCcAaBbCc AaBbccAaBbcc AabbCcAabbCc aaBbCcaaBbCc AabbccAabbcc aabbCcaabbCc aaBbccaaBbcc aabbccaabbcc

Polygenic Polygenic Inheritance Inheritance

GraphGraph

What effect does environment What effect does environment have on genes?have on genes?–Environment can affect how an Environment can affect how an

allele is expressedallele is expressed

–Temperature controls hair color Temperature controls hair color in the arctic harein the arctic hare

Norm of reaction – the phenotypic Norm of reaction – the phenotypic range associated with a specific range associated with a specific genotypegenotype

–Some genes have no range (ABO Some genes have no range (ABO blood types)blood types)

So FarSo FarMendel’s experimentsMendel’s experiments

1 Trait Cross (TT x tt)1 Trait Cross (TT x tt)

2 Trait Cross (GGTT x ggtt)2 Trait Cross (GGTT x ggtt)

Incomplete DominanceIncomplete Dominance

CodominanceCodominance

Multiple Alleles (Blood types)Multiple Alleles (Blood types)

EpistasisEpistasis

PleiotropyPleiotropy

PolygenicPolygenic

Sex-linkedSex-linked

PedigreesPedigrees

Inheritance PatternsInheritance PatternsAutosomal inheritance – both male and Autosomal inheritance – both male and female have 2 copies of each genefemale have 2 copies of each gene– 1 from each parent1 from each parent

Sex linked (X-linked usually) – females have 2 Sex linked (X-linked usually) – females have 2 copies and males only have 1 copy of the copies and males only have 1 copy of the genegene– Females – get an X chromosome from each Females – get an X chromosome from each

parentparent– Males – get their X from their mom and their Y Males – get their X from their mom and their Y

from their dadfrom their dad

Genes on the Male Sex Chromosomes

DOMINANT RECESSIVE

XHXH XHXh

XHY XhY

XH

Y

XH Xh

IV.IV. Sex-linked InheritanceSex-linked InheritanceA.A. Color Blindness – recessive, linked to the X Color Blindness – recessive, linked to the X

chromosomechromosome1.1. Cannot distinguish between colors like red Cannot distinguish between colors like red

and greenand green2.2. Genotypes:Genotypes:

a.a. XXCCXXCC – normal female, non carrier – normal female, non carrierb.b. XXCCXXc’c’ – normal female, carrier – normal female, carrier (may pass (may pass

recessive allele on to sons and/or recessive allele on to sons and/or daughters)daughters)

c.c. XXc’c’XXc’c’ – colorblind female – colorblind female (will pass (will pass recessive allele to all childrenrecessive allele to all children

d.d. XXCCY – normal maleY – normal malee.e. XXc’c’Y – colorblind male Y – colorblind male (will pass recessive (will pass recessive

allele to daughters only)allele to daughters only)

Thought questionThought questionInformationInformation– Turn in Fly LabTurn in Fly Lab– Test – Tuesday 1/26Test – Tuesday 1/26– We will start new material Thursday/FridayWe will start new material Thursday/Friday

Parental cross – BBTT x bbttParental cross – BBTT x bbttF1 Cross resultsF1 Cross results– Brown, Tall plants – 47Brown, Tall plants – 47– Brown, short – 3Brown, short – 3– White, tall – 3White, tall – 3– White, short – 47White, short – 47

How far apart are these two genesHow far apart are these two genes

Pedigrees Illustrate InheritancePedigrees Illustrate Inheritance

A A pedigreepedigree is a graphic representation of is a graphic representation of genetic inheritance.genetic inheritance.

It is a diagram made up of a set of It is a diagram made up of a set of symbols that identify males and females, symbols that identify males and females, individuals affected by the trait being individuals affected by the trait being studied, and family relationships.studied, and family relationships.

14-1 Human Heredity

Male

Female

Affected male

Affected female

Mating

Parents

Siblings

Known heterozygotes for recessive allele

Death

Pedigrees Illustrate InheritancePedigrees Illustrate Inheritance14-1 Human Heredity

Female Male

?

I

II

III

IV

1 2

1

1

1

32

2

2

4

3

3

5

4

4 5


In a pedigree, a In a pedigree, a circle represents a circle represents a female; a square female; a square represents a male.represents a male.– Highlighted circles Highlighted circles

and squares and squares represent individuals represent individuals showing the trait showing the trait being studied.being studied.

– Circles and squares Circles and squares that are not that are not highlighted highlighted designate designate individuals that do individuals that do not show the trait.not show the trait.

14-1 Human Heredity


A half-shaded circle A half-shaded circle or square represents or square represents a carrier, a a carrier, a heterozygous heterozygous individual.individual.

14-1 Human Heredity


A horizontal line connecting a A horizontal line connecting a circle and a square indicates circle and a square indicates that the individuals are that the individuals are parents, and a vertical line parents, and a vertical line connects parents with their connects parents with their offspring.offspring.Each horizontal row of circles Each horizontal row of circles and squares in a pedigree and squares in a pedigree designates a generation, with designates a generation, with the most recent generation the most recent generation shown at the bottom.shown at the bottom.The generations are identified The generations are identified in sequence by Roman in sequence by Roman numerals, and each individual numerals, and each individual is given an Arabic number.is given an Arabic number.

1 2

1

1

1

32

2

2

4

3

3

5

4

4 5

?

I

II

III

IV

14-1 Human Heredity

dd dd

dd dd dd

dd

Dd

Dd

Dd Dd

Dd

DdDd

DD

DDDDDD

DDDDDD

Dd

DdDdDdDd

DD

DdDdDdDd

DdDd

dddddd

dddddddd

dddd

Hemophilia pedigree beginning with Hemophilia pedigree beginning with Queen VictoriaQueen Victoria

PedigreesPedigrees

Square – maleSquare – male

Circle – femaleCircle – female

Shaded – has the trait you are studyingShaded – has the trait you are studying

Unshaded – has the other form of the Unshaded – has the other form of the genegene

Partial shading – carrier (sex-linked), could Partial shading – carrier (sex-linked), could be heterozygous for autosomalbe heterozygous for autosomal

Warm-upWarm-up

Have out the pedigree sheet, ch. 14 Have out the pedigree sheet, ch. 14 reading guide, and the genetics review reading guide, and the genetics review sheetsheet

Turn in ch. 15 reading guide to the front Turn in ch. 15 reading guide to the front traytray

Pick up a disease chart and an AP Lab 3 Pick up a disease chart and an AP Lab 3 handout from the fronthandout from the front

RemindersRemindersTEST – next WednesdayTEST – next Wednesday

AP Lab 3 starting tomorrowAP Lab 3 starting tomorrow– Read through the background info tonightRead through the background info tonight– Go through the lab bench tutorialGo through the lab bench tutorial

Quiz on Monday coveringQuiz on Monday covering– Crosses – 1 trait, 2 trait, sex-linked, blood Crosses – 1 trait, 2 trait, sex-linked, blood

types, incomplete/codominant, linked genes, types, incomplete/codominant, linked genes, recombination frequency, gene mappingrecombination frequency, gene mapping

Science fair judges – get 5Science fair judges – get 5thth period teacher period teacher to sign the permission slipto sign the permission slip

For AP Lab 3For AP Lab 3

Have to determine inheritance patterns for Have to determine inheritance patterns for 4 traits4 traits

Could beCould be– Linked/unlinkedLinked/unlinked– Sex-linkedSex-linked– Lethal (HH offspring do not develop)Lethal (HH offspring do not develop)

So FarSo FarMendel’s experimentsMendel’s experiments

1 Trait Cross (TT x tt)1 Trait Cross (TT x tt)

2 Trait Cross (GGTT x ggtt)2 Trait Cross (GGTT x ggtt)

Incomplete DominanceIncomplete Dominance

CodominanceCodominance

Multiple Alleles (Blood types)Multiple Alleles (Blood types)

EpistasisEpistasis

PleiotropyPleiotropy

PolygenicPolygenic

Sex-linkedSex-linked

PedigreesPedigrees

Add these words to your reviewAdd these words to your reviewHuntington’s diseaseHuntington’s disease

Tay sach’s diseaseTay sach’s disease

Cystic fibrosisCystic fibrosis

Down’s syndromeDown’s syndrome

Turner’s syndromeTurner’s syndrome

Klinefelter’s syndromeKlinefelter’s syndrome

HemophiliaHemophilia

ColorblindnessColorblindness

Complete dominanceComplete dominance

GametesGametes

Rh +/- factor – autosomalRh +/- factor – autosomal

Genomic ImprintingGenomic Imprinting

Go over pedigree sheetGo over pedigree sheet

TodayToday

We will look at:We will look at:– Linked vs unlinked genesLinked vs unlinked genes– Types of mutations and the diseases that Types of mutations and the diseases that

arise from themarise from them

Genetic recombinationGenetic recombination

Crossing overCrossing over Genes that DO NOT Genes that DO NOT

assort independently of each otherassort independently of each other

Genetic mapsGenetic mapsThe further apart 2 genes The further apart 2 genes

are, the higher the probability that are, the higher the probability that a crossover will occur between a crossover will occur between them and therefore the higher the them and therefore the higher the recombination frequencyrecombination frequency

Linkage mapsLinkage mapsGenetic map based on Genetic map based on

recombination frequenciesrecombination frequencies

Unlinked Autosomal GenesUnlinked Autosomal Genes

R r

Y y

Linked GenesLinked Genes

R r

Y y

RYRY ryry

RYRY RRYYRRYY RrYyRrYy

ryry RrYyRrYy rryyrryy

3 round, yellow : 1 wrinkled, green

Crossing over can Crossing over can create create

recombinantsrecombinants

Hypothetical Linked Gene DataHypothetical Linked Gene Data

Round, Yellow – 93Round, Yellow – 93

Round, Green – 7 (recombinants)Round, Green – 7 (recombinants)

Wrinkled, Yellow – 7 (recombinants)Wrinkled, Yellow – 7 (recombinants)

Wrinkled, Green – 93Wrinkled, Green – 93

Recombination Frequency = recombinant Recombination Frequency = recombinant total / total offspringtotal / total offspring

14/200 = 7%14/200 = 7%

Gene mappingGene mapping

Each % pt of recombinants = 1 map unit Each % pt of recombinants = 1 map unit on the chromosomeon the chromosome

R is 7 map units away from YR is 7 map units away from Y

R Y

7 map units

Linked genesLinked genes

Genes on the same chromosome that are 50 m.u.’s apart behave like unlinked genes – They are said to be genetically unlinked

Gene mapping worksheetGene mapping worksheet

After you are done, research the disease I After you are done, research the disease I assign you (using the book and/or assign you (using the book and/or smartphones)smartphones)– Fill out the appropriate row on the disease Fill out the appropriate row on the disease

chart – try to condense each box into a short chart – try to condense each box into a short phrase that you think is the essential infophrase that you think is the essential info

Add “prenatal testing” to the treatment boxAdd “prenatal testing” to the treatment box

– You will present your findings (1-2 min) to the You will present your findings (1-2 min) to the classclass

Become an expert at 1 of the diseases assignedBecome an expert at 1 of the diseases assigned

MutationsMutations

MutationsMutations

Mutations are defined as “a sudden Mutations are defined as “a sudden genetic change in the DNA genetic change in the DNA sequence that affects genetic sequence that affects genetic information”. information”.

They can occur at the molecular They can occur at the molecular level (genes) and change a single level (genes) and change a single gene, or at the chromosome level gene, or at the chromosome level and affect many genes.and affect many genes.

Most mutations are “spontaneous” Most mutations are “spontaneous” and have no known cause.and have no known cause.

Most are “Most are “silentsilent” and have no ” and have no effect on the organism.effect on the organism.

Things that can cause mutations Things that can cause mutations are called “are called “mutagensmutagens”. ”.

Known mutagens are ultraviolet Known mutagens are ultraviolet light, cigarette smoking, certain light, cigarette smoking, certain chemicals like PCB’s.chemicals like PCB’s.

Types of Mutations – mistakesTypes of Mutations – mistakes

a)a) Gene (point) MutationsGene (point) Mutations – occur at a – occur at a single genesingle gene

i.i. Germ mutationsGerm mutations – occur in gametes. – occur in gametes. Inheritable (colorblindness, hemophilia)Inheritable (colorblindness, hemophilia)

ii.ii. Somatic mutationsSomatic mutations – affect body cell, not – affect body cell, not inheritable (environmental factor of inheritable (environmental factor of cancer)cancer)

b)b) Chromosomal mutationsChromosomal mutations – most – most drastic, change in structure or # of drastic, change in structure or # of chromosomes (Downs’ syndrome)chromosomes (Downs’ syndrome)

III.III. Point MutationsPoint Mutations

a)a) SubstitutionSubstitution – one base exchanges – one base exchanges for another, affects 1 amino acidfor another, affects 1 amino acid(Ex. GC(Ex. GCAA-TCA -TCA GC GCTT-TCA-TCA

b)b) InsertionInsertion (frame shift) – 1 base is (frame shift) – 1 base is inserted, affects several amino acidsinserted, affects several amino acidsEx. (GCA-TCA Ex. (GCA-TCA GCA- GCA-GGTC-ATC-A

c)c) DeletionDeletion (frameshift)– base is (frameshift)– base is removed, affects several amino acidsremoved, affects several amino acidsEx. (GCEx. (GCA-A-TCA TCA GCT-CA GCT-CA

Point MutationPoint Mutation

Chromosomal errors, IChromosomal errors, INondisjunctionNondisjunction::members of a pair of members of a pair of homologous chromosomes do homologous chromosomes do not separate properly during not separate properly during meiosis I or sister chromatids meiosis I or sister chromatids fail to separate during meiosis fail to separate during meiosis IIII

Aneuploidy: chromosome Aneuploidy: chromosome number is abnormalnumber is abnormal

• Monosomy~ • Monosomy~ missing missing chromosomechromosome

• Trisomy~ extra • Trisomy~ extra chromosome (Down chromosome (Down syndrome)syndrome)• Polyploidy~ extra • Polyploidy~ extra

sets sets of chromosomesof chromosomes

AneuploidyPolyploidy

Other chromosomal errorsOther chromosomal errorsAlterations of chromosomal structure:Alterations of chromosomal structure:

Deletion: removal of a chromosomal segmentDeletion: removal of a chromosomal segment

Duplication: repeats a chromosomal segmentDuplication: repeats a chromosomal segment

Inversion: segment reversal in a chromosomeInversion: segment reversal in a chromosome

Translocation: movement of a chromosomal segment to Translocation: movement of a chromosomal segment to anotheranother

Disease ChartDisease Chart

We need to know what type of mutation We need to know what type of mutation causes certain diseasescauses certain diseases– Is the mutation dominant or recessiveIs the mutation dominant or recessive

Dominant – new protein created overshadows the Dominant – new protein created overshadows the original proteinoriginal protein

TodayTodayHave out:Have out:– AP Lab 3 – due on ThursdayAP Lab 3 – due on Thursday– Scratch paperScratch paper

RemindersReminders– Quiz on Monday coveringQuiz on Monday covering

Crosses – 1 trait, 2 trait, sex-linked, blood types, Crosses – 1 trait, 2 trait, sex-linked, blood types, incomplete/codominant, linked genes, incomplete/codominant, linked genes, recombination frequency, gene mappingrecombination frequency, gene mapping

– Ch. 14 reading guide – due Monday for 4pts Ch. 14 reading guide – due Monday for 4pts extra credit on last testextra credit on last test

Practice – Step 1Practice – Step 1Two plants (RRtt and rrTT) mate and have Two plants (RRtt and rrTT) mate and have offspringoffspring– R = roundR = round r = wrinkledr = wrinkled– T = tallT = tall t = shortt = short

2 of the F1 offspring then were mated together2 of the F1 offspring then were mated together

Draw 2 punnett squaresDraw 2 punnett squares– 1 if the R and T genes were on different 1 if the R and T genes were on different

chromosomes (unlinked)chromosomes (unlinked)– 1 if the R and T genes were on the same 1 if the R and T genes were on the same

chromosome (linked)chromosome (linked)

Predict the phenotypic ratios for each situationPredict the phenotypic ratios for each situation

Phenotypic ratiosPhenotypic ratios

UnlinkedUnlinked– Round, tall – 9/16Round, tall – 9/16– Round, short – 3/16Round, short – 3/16– Wrinkled, tall – 3/16Wrinkled, tall – 3/16– Wrinkled, short – 1/16Wrinkled, short – 1/16

LinkedLinked– Round, tall – 2/4Round, tall – 2/4– Round, short – 1/4Round, short – 1/4– Wrinkled, tall – 1/4Wrinkled, tall – 1/4– Wrinkled, short – 0/4Wrinkled, short – 0/4

Actual ResultsActual Results

Round, tall – 96Round, tall – 96

Round, short – 47Round, short – 47

Wrinkled, tall – 53Wrinkled, tall – 53

Wrinkled, short – 4Wrinkled, short – 4

Calculate the recombinant (crossover) Calculate the recombinant (crossover) frequency %frequency %

Recombination Frequency = recombinant Recombination Frequency = recombinant total / total offspringtotal / total offspring

4/ (96+47+53+4) = 4/200 = 2%4/ (96+47+53+4) = 4/200 = 2%

These genes are 2 map units away from These genes are 2 map units away from each other on the same chromosomeeach other on the same chromosome

Let’s say that we studied other genes as Let’s say that we studied other genes as well and found these recombination well and found these recombination frequenciesfrequencies

R/T – 4%R/T – 4%

R/G – 23 %R/G – 23 %

R/Q – 11%R/Q – 11%

G/Q – 12%G/Q – 12%

G/T – 19%G/T – 19%

4 mu 7 mu 12 mu

R T Q G

TodayToday

Turn in Ch. 14 to the front tray if you did it Turn in Ch. 14 to the front tray if you did it (optional)(optional)

Have out disease chart (diseases not on Have out disease chart (diseases not on quiz, but will be on test)quiz, but will be on test)

Have out AP Lab 3Have out AP Lab 3

RemindersReminders

Test is on WednesdayTest is on Wednesday

Lab due on ThursdayLab due on Thursday

AP Lab 3AP Lab 3

Cross a ++ male with BlBl mutant femaleCross a ++ male with BlBl mutant female– Which ever phenotype is displayed is Which ever phenotype is displayed is

dominantdominant

Do the reverse cross (++ female X BlBl Do the reverse cross (++ female X BlBl male)male)– If male and female have the same If male and female have the same

phenotypes, most-likely it is not sex-linkedphenotypes, most-likely it is not sex-linked

For 2 trait crossesFor 2 trait crosses

DiseasesDiseases

Chi-squaredChi-squared

Genetics ProblemsGenetics Problems

TodayToday

1.1. Create 2 parents of whatever organism Create 2 parents of whatever organism you choose (from the natural world or you choose (from the natural world or something made up)something made up)

2.2. Draw, label, and color 5 traits (1 is sex-Draw, label, and color 5 traits (1 is sex-linked) for each parent (one parent is linked) for each parent (one parent is going to be heterozygous for each trait)going to be heterozygous for each trait)

3.3. 2 parents with 5 traits (1 sex-linked)2 parents with 5 traits (1 sex-linked)-1 parent has to be pure heterozygous (dominant for each trait)-1 parent has to be pure heterozygous (dominant for each trait)- The other parent can be up to you- The other parent can be up to you

4.4. Make 5 crosses Make 5 crosses a)a)Monohybrid – 1trait cross, non sex-linkedMonohybrid – 1trait cross, non sex-linkedb)b)Dihybrid – unlinkedDihybrid – unlinkedc)c)Dihybrid - linkedDihybrid - linkedd)d)TrihybridTrihybride)e)Sex-linkedSex-linked

5.5. For each crossFor each crossa)a)Assign letters for traitAssign letters for traitb)b)Write parental cross (genotypes)Write parental cross (genotypes)c)c)Write the gametes each parent can possibly give their childrenWrite the gametes each parent can possibly give their childrend)d)Work the punnett square using those gametesWork the punnett square using those gametese)e)Give me genotypic ratios and percentagesGive me genotypic ratios and percentagesf)f)Give me phenotypic ratios and percentagesGive me phenotypic ratios and percentages

6.6. Due on TuesdayDue on Tuesday

Genomic imprintingGenomic imprinting

Def: a parental effect on Def: a parental effect on gene expressiongene expression

Identical alleles may have Identical alleles may have different effects on different effects on offspring, depending on offspring, depending on whether they arrive in the whether they arrive in the zygote via the ovum or zygote via the ovum or via the sperm.via the sperm.

Fragile X syndrome: Fragile X syndrome: higher prevalence of higher prevalence of disorder and retardation disorder and retardation in malesin males

Bonus – answer after essaysBonus – answer after essays1.1. What molecules do CDK’s need to bind with What molecules do CDK’s need to bind with

in order to be activated?in order to be activated?2.2. What checkpoint on the cell cycle does MPF What checkpoint on the cell cycle does MPF

allow a cell to go past?allow a cell to go past?3.3. What are the proteins that are released from What are the proteins that are released from

cells to cause other cells to divide?cells to cause other cells to divide?4.4. What is the phenomenon called when cells What is the phenomenon called when cells

that are crowded stop dividing?that are crowded stop dividing?5.5. The spread of cancer cells to locations The spread of cancer cells to locations

distant from their origin is called distant from their origin is called ________________.________________.

Genetics Yeah-ya! -You need an individual whiteboard for you and a big whiteboard for your group.

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