PROTEIN SYNTHESISPROTEIN SYNTHESISTRANSCRIPTION: DNATRANSCRIPTION: DNA m RNA m RNA TRANSLATION: m RNA TRANSLATION: m RNA ProteinProtein

Summary of Events in Protein SynthesisSummary of Events in Protein Synthesis

TRANSCRIPTIONTRANSCRIPTION

Transcription: A Deep lookTranscription: A Deep lookA. RNA is made from the DNA nucleotide

sequence during transcription.

1. __________________attaches to the beginning of one gene or a group of genes, called the ___________, on

the DNA molecule. 2. DNA separates at

the______________________ 3. half the DNA serves as a template to make RNA from nucleotides

a. base sequence in a. base sequence in DNADNA determines the base sequence in determines the base sequence in the the RNARNA molecule molecule 4. transcription ends at the 4. transcription ends at the

_______________________________________________________________________on the DNA molecule_____on the DNA molecule

a. indicates the end of a ___________or a. indicates the end of a ___________or a a

group of genes group of genes 5. m-RNA, t-RNA and r-RNA may be5. m-RNA, t-RNA and r-RNA may be mademade

Transcription Transcription

http://www.biostudio.com/d_%20Transcription.htmhttp://www.stolaf.edu/people/giannini/flashanimat/molgenetics/transcription.swf

FIND MORE WEBSITES…FIND MORE WEBSITES…

TRANSLATIONTRANSLATION

Translation- in ribosomesTranslation- in ribosomes_________makes proteins with the help of _________makes proteins with the help of _____________._____________.The ___________on the mRNA dictate the amino The ___________on the mRNA dictate the amino acids that the tRNA brings to the ribosome.acids that the tRNA brings to the ribosome.The ________________ on the tRNA hooks up The ________________ on the tRNA hooks up with the CODON and the a.a. is brought to the with the CODON and the a.a. is brought to the appropriate location.appropriate location.Translation starts at the start codon (AUG) and Translation starts at the start codon (AUG) and ends at the stop codon (UGA, UAG, UAA)ends at the stop codon (UGA, UAG, UAA)

Chain of amino acid= proteinChain of amino acid= protein

B. B.

B. How is the sequence of amino acids B. How is the sequence of amino acids determined in translation?determined in translation?1.1.codoncodon (3-base sequence on m-RNA(3-base sequence on m-RNA) ) a. 64 codons- code for amino acidsa. 64 codons- code for amino acids2. 2. start codonstart codon (AUG) starts translation (AUG) starts translation a. it codes for thea. it codes for the methioninemethionine3. codons on m-RNA pair with 3. codons on m-RNA pair with

anticodonsanticodons on t-RNA on t-RNA4. 4. stop codonsstop codons (UAA, UAG, UGA) stop (UAA, UAG, UGA) stop translationtranslation

Codon ChartCodon Chart

Start and Stop Codons on RNAStart and Stop Codons on RNA

Stop Codon AnimationStop Codon Animation

Peptide Bond FormationPeptide Bond Formation

PROTEIN SYNTHESIS SUMMARYPROTEIN SYNTHESIS SUMMARY

TranscriptionTranscription - DNA makes RNA - DNA makes RNATranslationTranslation – t-RNA anticodons line – t-RNA anticodons line up with m-RNA codons at the up with m-RNA codons at the ribosomeribosomepeptide bonds connect amino acids peptide bonds connect amino acids in in dehydration synthesisdehydration synthesisthe the GENETIC CODEGENETIC CODE is the correlation is the correlation between between DNA base sequenceDNA base sequence and and amino acid sequenceamino acid sequence in a in a polypeptidepolypeptide

TRANSLATIONTRANSLATIONWork on the building of Protein at the following Work on the building of Protein at the following websitewebsitehttp://www.pbs.org/wgbh/aso/tryit/dna/

http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/animations/protein_synthesis/protein_synthesis.html

http://www.brooklyn.cuny.edu/bc/ahp/BioInfo/http://www.brooklyn.cuny.edu/bc/ahp/BioInfo/SD.TransTrans.HP.htmlSD.TransTrans.HP.html

http://learn.genetics.utah.edu/content/begin/dna/transcribe/http://www.biostudio.com/demo_freeman_protein_synthesis.htm  (w the ribosome subunits)  (w the ribosome subunits)  http://www.brookscole.com/chemistry_d/templates/http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/animations/student_resources/shared_resources/animations/protein_synthesis/protein_synthesis.htmlprotein_synthesis/protein_synthesis.html  http://learn.genetics.utah.edu/units/basics/http://learn.genetics.utah.edu/units/basics/transcribe/ (actual do it yourself protein)transcribe/ (actual do it yourself protein)  http://www.cst.cmich.edu/users/Benja1dw/BIO101/http://www.cst.cmich.edu/users/Benja1dw/BIO101/tools/quiz/dnarna.htm tools/quiz/dnarna.htm 

GENES ARE SEGMENTS OF DNATHAT CODE FOR A CHARACTERISTIC, LIKE DIMPLES. REALLY ITS _______________________________IN THE DNA DETERMINE THE CHARACTERISTIC. BUT SOMETIMES PROBLEMS ARISE….

MutationsMutationsA. Location of MutationsA. Location of Mutations 1. 1. __________________________(body cell)(body cell) 2. 2. _________cell_________cell (cells that form sperm (cells that form sperm and egg cells)and egg cells)B. CausesB. Causes 1. radiation 1. radiation a. x-rays, alpha, beta, gamma a. x-rays, alpha, beta, gamma radiation, u.v. lightradiation, u.v. light 2. chemicals (2. chemicals (mutagensmutagens)) 3. DNA sequence changes in replication 3. DNA sequence changes in replication

C. Effects of MutationsC. Effects of Mutations 1.__________(deadly) 1.__________(deadly)

2. may be beneficial2. may be beneficial 3. no effect3. no effect

Point MutationPoint Mutation

change in one nucleotide …or change in a change in one nucleotide …or change in a basebase (A,T,C,G) in the DNA molecule (A,T,C,G) in the DNA molecule

Types of mutations –

a. ___________ – one base is

substituted for another b. _____________– an extra base is added c. __________ or deletion of

a base

Point Mutation:Point Mutation:Substitution of One BaseSubstitution of One Base

BIGGER PROBLEMS…BIGGER PROBLEMS…WHEN ONE OR TWO BASES ARE WHEN ONE OR TWO BASES ARE ADDED/DELETED, EVEN BIGGER PROBLEMS ADDED/DELETED, EVEN BIGGER PROBLEMS ARISE BECAUSE DNA IS ARISE BECAUSE DNA IS “READ” “READ” IN________________SEQUENCES.IN________________SEQUENCES.

TRANSLATION? EVERY 3 DNA BASES CODE TRANSLATION? EVERY 3 DNA BASES CODE FOR AN AMINO ACID (REMEMBER THE FOR AN AMINO ACID (REMEMBER THE BUILDING BLOCK OF PROTIENS) AND YOU BUILDING BLOCK OF PROTIENS) AND YOU KNOW THAT PROTEINS ARE EVERYWHERE IN KNOW THAT PROTEINS ARE EVERYWHERE IN OUR BODIES! OUR BODIES!

TO UNDERSTAND WHY, WE NEED TO TO UNDERSTAND WHY, WE NEED TO UNDERSTAND HOW PROTEINS ARE FORMED.UNDERSTAND HOW PROTEINS ARE FORMED.

FrameshiftFrameshift – results when the number – results when the number of nucleotides inserted or deleted is of nucleotides inserted or deleted is not a multiple of threenot a multiple of three

1. addition or deletion can result1. addition or deletion can result in a in a ______________________________ 2. results in a completely different2. results in a completely different sequence of amino acids in thesequence of amino acids in the polypeptide chainpolypeptide chain

When things go wrong…When things go wrong…

FrameshiftFrameshift

Frameshift- InsertionFrameshift- Insertion

CELL CYCLE CONTROL BY CELL CYCLE CONTROL BY PROTEINSPROTEINS

What happens when the cell cycle proteins What happens when the cell cycle proteins are the ones being mutated?are the ones being mutated?

Loss of Control of the Cell Cycle if checkpoints are not working properly, the

cell cycle can cause the cell to grow uncontrollably

leads to _________

http://outreach.mcb.harvard.edu/animations_S03.htm

How does variation get passed on?How does variation get passed on?REPRODUCTION!!!!REPRODUCTION!!!!

Knowing DNA stores the message for all Knowing DNA stores the message for all characteristics, how does it get passed on? characteristics, how does it get passed on? ____________________________________________Types of reproductionTypes of reproduction– Asexual (Mitosis)- which produces identical Asexual (Mitosis)- which produces identical

offspring (e.g. budding, binary fission)offspring (e.g. budding, binary fission)– Sexual (Meiosis)- which produces egg and Sexual (Meiosis)- which produces egg and

sperm.sperm.

Heredity- How genetic traits are passed from Heredity- How genetic traits are passed from one generation to another one generation to another

ASEXUAL REPRODUCTION (MITOSIS) IS ONLY 1 WAY

ORGANISMS (SIMPLE) REPRODUCE! THERE ARE

SOME ADVANTAGES (____________), BUT A HUGE DISADVANTAGE-

NO ___________IN OFFSPRING!!!

Sexual vs Asexual ReproductionSexual vs Asexual Reproduction

Asexual Asexual

One parentOne parent__________geneti__________genetic materialc materialMitosis, budding, Mitosis, budding, binary fissionbinary fission

Sexual Sexual

Two parentsTwo parentsDifferent genetic Different genetic materialmaterialMeiosis + Meiosis + ____________________________

What is Meiosis Exactly?What is Meiosis Exactly?

Meiosis is a form of cell division that halves Meiosis is a form of cell division that halves the number of chromosomes when forming the number of chromosomes when forming specialized reproductive cells such as specialized reproductive cells such as gametes or sporesgametes or spores

2 CELL DIVISIONS: Meiosis 1 and meiosis 22 CELL DIVISIONS: Meiosis 1 and meiosis 2

CREATE 4__________cells (1N) only 1 copy CREATE 4__________cells (1N) only 1 copy of the chromosomes.of the chromosomes.

MITOSIS VS. MEIOSISMITOSIS VS. MEIOSISMitosis- process that happens during 1) growth 2) Mitosis- process that happens during 1) growth 2) asexual reproduction 3) repair of cells 4)regenerationasexual reproduction 3) repair of cells 4)regenerationAFTER 4 STAGES (P-M-A-T) and 1 cell division IT AFTER 4 STAGES (P-M-A-T) and 1 cell division IT PRODUCES 2 CELLS IDENTICAL (_____________) TO PRODUCES 2 CELLS IDENTICAL (_____________) TO THE PARENT CELL- SAME DNATHE PARENT CELL- SAME DNA

VS.VS.Meiosis- process that happens to make sex cells (egg Meiosis- process that happens to make sex cells (egg and sperm)and sperm)AFTER ____ STAGES (PMAT-P2M2A2T2) and 2 cell AFTER ____ STAGES (PMAT-P2M2A2T2) and 2 cell divisions, IT PRODUCES_____CELLS WITH divisions, IT PRODUCES_____CELLS WITH DIFFERENT GENETIC INFO FROM PARENTDIFFERENT GENETIC INFO FROM PARENT

REMEMBER CHROMOSOMESREMEMBER CHROMOSOMES

THEY ARE DNA STRANDS WRAPPED AROUND THEY ARE DNA STRANDS WRAPPED AROUND HISTONE PROTEINS.HISTONE PROTEINS.IN ALL _______________THEY COME IN PAIRS IN ALL _______________THEY COME IN PAIRS (2N) CALLED THE ______________ NUMBER. (2N) CALLED THE ______________ NUMBER. ONE OF THE PAIR IS FROM MOM/DAD. ONE OF THE PAIR IS FROM MOM/DAD. – We have 46 chromosomes in body cells- 23 pairs.We have 46 chromosomes in body cells- 23 pairs.SINCE IN SEX CELLS THERE NEEDS TO BE ½ SINCE IN SEX CELLS THERE NEEDS TO BE ½ THE # OF CHROMOSOMES, THEY ARE NO THE # OF CHROMOSOMES, THEY ARE NO LONGER IN PAIRS…THEY ARE ALONE. THIS LONGER IN PAIRS…THEY ARE ALONE. THIS IS CALLED THE _____________ (HALF) IS CALLED THE _____________ (HALF) NUMBER (1N)NUMBER (1N)– We have 23 chromosomes in egg/sperm.We have 23 chromosomes in egg/sperm.

Stages of Meiosis 1Stages of Meiosis 1

Stages of Meiosis 2Stages of Meiosis 2

S phase of Interphase S phase of Interphase (Before Replication- Mitosis)(Before Replication- Mitosis)

Interphase after replicationInterphase after replication

I. Meiosis (Reduction Division)I. Meiosis (Reduction Division)A. Meiosis IA. Meiosis I1. __________________1. __________________ a. chromosomes become distincta. chromosomes become distinct b. nucleolus and nuclear membraneb. nucleolus and nuclear membrane disappear and spindle fibers appeardisappear and spindle fibers appear

Prophase IProphase I

c. spindle fibers appearc. spindle fibers appeard.d.________________________–homologous –homologous

chromosomes chromosomes Line up together Line up together form form ________________________

(group of 4)(group of 4)

Prophase IProphase I

e. e. ________________________________________may occur may occur 1) portions of chromatid from one1) portions of chromatid from one parent break off and attach to a parent break off and attach to a homologous chromatid from the homologous chromatid from the other parentother parent 2) results in 2) results in ____________________________________________________________

2. 2. __________________________________________ a. chromosomes line up along the a. chromosomes line up along the

midlinemidline b. sister chromatids b. sister chromatids do notdo not separate separate

3. 3. ________________________________________ a. at random, one member of each a. at random, one member of each homologous pair moves to the homologous pair moves to the opposite poles opposite poles

((______________________________________________________________))

4. 4. _________________and Cytokinesis _________________and Cytokinesis II

a. chromosomes reach opposite a. chromosomes reach opposite polespoles

b. cytokinesis beginsb. cytokinesis begins

Telophase ITelophase I

c. resulting cells have the c. resulting cells have the n n or______________or______________number of number of chromosomes chromosomes

1) one member of each homologous 1) one member of each homologous pair with two attached chromatids pair with two attached chromatids

d. each new cell contains ½ the d. each new cell contains ½ the the number of chromosomes as the number of chromosomes as

the original cell the original cell

B. B. Meiosis IIMeiosis II

1. 1. ______________________________________ a. spindle form and chromosomes a. spindle form and chromosomes begin to move toward the mid-line begin to move toward the mid-line

of of the cellthe cell

. . ________________________________________ a. chromosomes move to the mid-a. chromosomes move to the mid-

line of the dividing cellline of the dividing cell

3.3. __________________________________________ a. chromatids separate and move to a. chromatids separate and move to

the opposite poles of the cellthe opposite poles of the cell

4. ______________________4. ______________________ a. nuclear membrane forms around a. nuclear membrane forms around

the nucleus in each cellthe nucleus in each cell b. each resulting cell contains the b. each resulting cell contains the nn number of chromosomes number of chromosomes

Meiosis 1 and Meiosis 2Meiosis 1 and Meiosis 2

Chart Comparing Mitosis and MeiosisChart Comparing Mitosis and Meiosis

MitosisMitosis2 cells result2 cells resultOne divisionOne division22nn number of number of chromosomes in chromosomes in resulting cellsresulting cellsDaughter cells Daughter cells are identicalare identical

MeiosisMeiosis4 cells result4 cells resultTwo divisionsTwo divisionsnn number of number of chromosomes in chromosomes in resulting cellsresulting cellsDaughter cells Daughter cells are all differentare all different

E. Formation of GametesE. Formation of Gametes

1. 1. ______________________________________ – results in 4 – results in 4 viable spermviable sperm

2. 2. ______________________________ – results in 1 egg – results in 1 egg andand

3 3 polar bodiespolar bodies

SpermatogenesisSpermatogenesis

OogenesisOogenesis

Fertilization [sperm (n) + egg (n) Fertilization [sperm (n) + egg (n) zytote zytote (2n) ](2n) ]

Sexual vs Asexual ReproductionSexual vs Asexual Reproduction

Asexual Asexual

One parentOne parentIdentical genetic Identical genetic materialmaterialMitosis, budding, Mitosis, budding, binary fissionbinary fission

Sexual Sexual

Two parentsTwo parentsDifferent genetic Different genetic materialmaterialMeiosis + Meiosis + fertilizationfertilization

WHEN THINGS GO WRONG!WHEN THINGS GO WRONG!

__________________________________________ 1. Down’s Syndrome (extra 21)1. Down’s Syndrome (extra 21) 2. Patau’s Syndrome (extra 13)2. Patau’s Syndrome (extra 13) 3. Edward’s Syndrome (extra 18)3. Edward’s Syndrome (extra 18) 4. Klinefelter’s Syndrome (XXY)4. Klinefelter’s Syndrome (XXY) 5. Turner’s Syndrome (XO)5. Turner’s Syndrome (XO)

NondisjunctionNondisjunction occurs when homologous occurs when homologous chromosomes do not segregate in meiosis I chromosomes do not segregate in meiosis I

or sister chromatids do not separate inor sister chromatids do not separate in meiosis IImeiosis II ( (causescauses __________ __________ andand

monosomymonosomy))

Other Chromosome Mutations……..Other Chromosome Mutations……..

1. 1. DeletionDeletion – piece of chromosome – piece of chromosome is deleted or is deleted or

__________________________ – piece of a chromosome – piece of a chromosome is duplicatedis duplicated

2. 2. InversionInversion – segment of a chromosome – segment of a chromosome is invertedis inverted

Chromosome Mutation - DuplicationChromosome Mutation - Duplication

Chromosome MutationsChromosome MutationsDeletion and DuplicationDeletion and Duplication

3.3. TranslocationTranslocation – – pieces of non homologous pieces of non homologous chromosomes are exchangedchromosomes are exchanged

46

23

23

23

23

23

23

How would it affect evolution if there How would it affect evolution if there was no genetic variation through was no genetic variation through

mutation or crossing over of genes?mutation or crossing over of genes?

REPRODUCTION AND HEREDITYREPRODUCTION AND HEREDITY

HOW GENES ARE PASSED ON!!HOW GENES ARE PASSED ON!!

I. Gregor Mendel (1822-1884)I. Gregor Mendel (1822-1884)

A. BackgroundA. Background 1. entered monastery at 211. entered monastery at 21 2. studied math and science2. studied math and science at University of Viennaat University of Vienna 3. 1857-1865 – investigated3. 1857-1865 – investigated inheritance in pea plantsinheritance in pea plants

Gregor Mendel The MonasteryGregor Mendel The Monastery

B. Peas – A Fortunate ChoiceB. Peas – A Fortunate Choice (Pisum sagivum)(Pisum sagivum) 1. distinct characteristics1. distinct characteristics (flower color, flower position,(flower color, flower position, seed color, seed texture, height) seed color, seed texture, height)

2. easy to grow2. easy to grow 3. mature quickly3. mature quickly 4. easy to pollinate4. easy to pollinate

D. Mendel’s ExperimentsD. Mendel’s Experiments 1. 1. PP11 Generation Generation (Parental) (Parental) a. crossed plants pure for a traita. crossed plants pure for a trait 2. 2. FF11 Generation Generation (Offspring of P (Offspring of P11)) a. all plants show one form of a. all plants show one form of the trait the trait 3. 3. FF22 Generation Generation (Offspring of F(Offspring of F11)) a. show forms of trait in 3:1 a. show forms of trait in 3:1 ratioratio

Mendel’s P, FMendel’s P, F11and Fand F22 Generations Generations

Examples of PExamples of P11 Cross Cross

Tall X ShortTall X Short (both are pure)(both are pure)T T X t tT T X t t All offspring are tall (T t) FAll offspring are tall (T t) F11 Generation GenerationFF11 Generation (all are ___________) Generation (all are ___________)

Purple Flower X White FlowerPurple Flower X White Flower (both pure)(both pure)P P X p pP P X p pAll ___________ are purple (Pp) FAll ___________ are purple (Pp) F11 Generation GenerationFF11 Generation (all are hybrids) Generation (all are hybrids)

Mendel’s FMendel’s F11 Cross (hybrid x hybrid) Cross (hybrid x hybrid)

Tall X TallTall X Tall (hybrid cross) (hybrid cross)T t X T tT t X T t 3 tall plants : 1 short plant (F3 tall plants : 1 short plant (F22 Generation) Generation)

Ratio of 3:1Ratio of 3:1Purple Flowers X Purple FlowersPurple Flowers X Purple Flowers (hybrid) (hybrid)P p X P pP p X P p 3 purple flower plants : 1 white flower (F3 purple flower plants : 1 white flower (F22))

Ratio of _________Ratio of _________

E. Analysis of Mendel’s ResultsE. Analysis of Mendel’s Results

1. traits controlled by a pair of 1. traits controlled by a pair of factorsfactors

a. today factors are called a. today factors are called allelesalleles 2. 2. Principle of ________________Principle of ________________ a. one factor (gene) can preventa. one factor (gene) can prevent expression of another (dominance)expression of another (dominance)

3. 3. Law of ___________________Law of ___________________ a. a pair of factors separate whena. a pair of factors separate when gametes form (during meiosis)gametes form (during meiosis)

4. 4. Law of Law of ______________________________________________________________

a. factors (genes) for differenta. factors (genes) for different characteristics separatecharacteristics separate independently … independently … (just b/c you have blonde hair doesn’t (just b/c you have blonde hair doesn’t

mean you’ll have blue eyes)mean you’ll have blue eyes)

II. VocabularyII. Vocabulary A. A. GenotypeGenotype 1. genetic makeup1. genetic makeup 2. examples 2. examples a. a. TT, Tt, tt,TT, Tt, tt, b. b. ____________________________________B. B. PhenotypePhenotype 1. external appearance1. external appearance 2. examples2. examples a. tall, shorta. tall, short b. purple flowers, white flowers b. purple flowers, white flowers

C. C. HomozygousHomozygous (pure) (pure) 1. two alleles code for the same trait 1. two alleles code for the same trait 2. examples 2. examples a. a. TT, tt, PP, ppTT, tt, PP, ppD. D. HeterozygousHeterozygous (hybrid)(hybrid) 1. two alleles do not code for the 1. two alleles do not code for the same traitsame trait 2. examples2. examples a. a. ________________________________

EE. . DominantDominant (represented by upper (represented by upper case letter)case letter)

1. allele that masks the recessive1. allele that masks the recessive allele for the same characteristicallele for the same characteristicF.F. RecessiveRecessive (represented by lower (represented by lower case letter)case letter) 1. allele that is masked by the1. allele that is masked by the dominant allele for the samedominant allele for the same characteristic characteristic

III. Complete DominanceIII. Complete Dominance (Monohybrid Cross) (Monohybrid Cross)

A. Both parents are pureA. Both parents are pure 1. homozygous x homozygous1. homozygous x homozygous 2. example 2. example T T x t t T T x t t

B. Both parents are hybridB. Both parents are hybrid 1. heterozygous X heterozygous1. heterozygous X heterozygous 2. example 2. example Tt x TtTt x Tt

III. Complete DominanceIII. Complete Dominance

C. Pure parent X hybrid parentC. Pure parent X hybrid parent1.homozygous dominant X heterozygous1.homozygous dominant X heterozygous a. Example a. Example T T x T t T T x T t 2.homozygous recessive x heterozygous2.homozygous recessive x heterozygous a. Example a. Example tt x Tttt x Tt

IV. Incomplete DominanceIV. Incomplete Dominance (both alleles influence the trait) (both alleles influence the trait)

A. Pure X Pure = all hybridsA. Pure X Pure = all hybrids1.example (red flower and white 1.example (red flower and white

flower)flower) a. a. RR x WWRR x WW B. Hybrid X HybridB. Hybrid X Hybrid 1. example (pink x pink flower)1. example (pink x pink flower) a. a. RW x RWRW x RWC. Pure X hybridC. Pure X hybrid 1.example (red x pink or white x pink)1.example (red x pink or white x pink) a. RR x RW or WW x RW a. RR x RW or WW x RW

Incomplete Dominance Four O’clock Incomplete Dominance Four O’clock FlowersFlowers

Pink (RW) White (WW) Red Pink (RW) White (WW) Red (RR)(RR)

V. Codominance V. Codominance (both alleles are expressed) (both alleles are expressed)

A. Pure X PureA. Pure X Pure 1. example (white horse x red horse)1. example (white horse x red horse) a. a. WW x RRWW x RRB. Hybrid x Hybrid B. Hybrid x Hybrid 11.. exampleexample (roan horse x roan horse) (roan horse x roan horse) a. a. RW x RWRW x RWC. Pure X HybridC. Pure X Hybrid 1. example(red x roan or white x roan)1. example(red x roan or white x roan) a. a. RR x RW or WW x RWRR x RW or WW x RW

VI. Dihybrid Cross VI. Dihybrid Cross (two traits considered) (two traits considered)

A. Homozygous X homozygousA. Homozygous X homozygous 1. all offspring are heterozygous for1. all offspring are heterozygous for both traits (all are hybrids)both traits (all are hybrids)

B. Heterozygous X heterozygousB. Heterozygous X heterozygous 1. 4 phenotypes possible1. 4 phenotypes possible 2. phenotype ratio 9:3:3:12. phenotype ratio 9:3:3:1

Dihybrid CrossDihybrid Cross

VII. Test CrossVII. Test Cross

A. PurposeA. Purpose 1. to help determine the genotype1. to help determine the genotype of an organismof an organism

B. ProcedureB. Procedure 1. cross individual with unknown1. cross individual with unknown genotype with individual withgenotype with individual with homozygous recessive individualhomozygous recessive individual 2. example T t x tt or T T x tt2. example T t x tt or T T x tt

VIII. Multiple Allele Problems (Blood VIII. Multiple Allele Problems (Blood Types)Types)

A. A. PHENOTYPEPHENOTYPE Type AType A

Type BType B

Type ABType AB

Type OType O

B. B. GENOTYPEGENOTYPE AA, AOAA, AO ( I( IAA I IAA , I , IAA i ) i )

BB, BOBB, BO ( I( IBB I IBB , I , IBB i ) i )

AB AB ( I( IAA I IBB ) )

OOOO ( ii )( ii )

Blood Donors and RecipientsBlood Donors and Recipients

World Distribution of the A AlleleWorld Distribution of the A Allele

World Distribution of the B AlleleWorld Distribution of the B Allele

World Distribution of Type O BloodWorld Distribution of Type O Blood

VIII. Multiple Allele ProblemsVIII. Multiple Allele Problems Blood Types Blood Types

C. One parent has type C. One parent has type ABAB blood and one has blood and one hastype type OO. What blood types are possible in the . What blood types are possible in the offspring?offspring?

D. One parent has type D. One parent has type AA blood and one has blood and one has typetype B B blood, what are the possible blood blood, what are the possible blood types in the offspring? types in the offspring?

IX. Polygenic inheritance of TraitsIX. Polygenic inheritance of Traits

A. Influenced by several genesA. Influenced by several genes 1. often show much variation1. often show much variation

B. ExamplesB. Examples 1. hair color, eye color, skin color1. hair color, eye color, skin color 2. height2. height 3. foot size, nose length3. foot size, nose length

Frequency Distribution of a Polygenic Frequency Distribution of a Polygenic TraitTrait

X. Sex-linked Inheritance X. Sex-linked Inheritance (X (X linked-carriedlinked-carried on X on X

chromosome)chromosome)

A. Examples of sex-linked traitsA. Examples of sex-linked traits 1. color blindness1. color blindness 2. _____________2. _____________ 3. muscular dystrophy3. muscular dystrophy 4. Icthyosis4. Icthyosis

Individual Individual ChromosomesChromosomes

Normal MaleNormal MaleMale with DiseaseMale with Disease

Normal FemaleNormal FemaleFemale CarrierFemale CarrierFemale - DiseaseFemale - Disease

X YX Y X* YX* Y

X XX X X* XX* X X* X*X* X*

Problem Solving- Sex Linked DiseasesProblem Solving- Sex Linked Diseases

A. A man is colorblind and his wife is a carrier A. A man is colorblind and his wife is a carrier for colorblindness. What is the probability thatfor colorblindness. What is the probability thatthey will have a child who is colorblind? they will have a child who is colorblind? (A son? A daughter?)(A son? A daughter?)

B. A man and woman are both colorblind. CanB. A man and woman are both colorblind. Canthey have a child who is not colorblind?they have a child who is not colorblind?(A son? A daughter?)(A son? A daughter?)

XI.Sex-influenced Inheritance XI.Sex-influenced Inheritance (Baldness)(Baldness)

Normal Male bbNormal Male bbBald Male Bb, BBBald Male Bb, BB

Normal Female bbNormal Female bbFemale Carrier BbFemale Carrier BbBald Female BBBald Female BB

Sex-influenced Inheritance–Problem Sex-influenced Inheritance–Problem SolvingSolving

A. If a man is bald and his wife carries a geneA. If a man is bald and his wife carries a genefor baldness, what is the chance of his sonfor baldness, what is the chance of his sonbeing bald? (His daughter?)being bald? (His daughter?)

B. If a man is not bald but his wife carries a B. If a man is not bald but his wife carries a gene for baldness, can his son be bald?gene for baldness, can his son be bald?(His daughter?)(His daughter?)

Pedigree-a genetic family treePedigree-a genetic family treehttp://genetics.gsk.com/graphics/autosomal_recessive.gifhttp://genetics.gsk.com/graphics/autosomal_recessive.gif

htt://

Pedigree chart tells us two thingsPedigree chart tells us two things– 1. WHETHER IT IS AN AUTOSOMAL(22 BODY 1. WHETHER IT IS AN AUTOSOMAL(22 BODY

PAIRS) OR SEX-LINKED (1PAIR OF SEX TRAITS PAIRS) OR SEX-LINKED (1PAIR OF SEX TRAITS XX OR XY) If male and female is close to equal it is XX OR XY) If male and female is close to equal it is autosomalautosomal

– 2. WHETHER IT IS DOM. OR RECESS. TRAIT- IF 2. WHETHER IT IS DOM. OR RECESS. TRAIT- IF THE TRAIT IS PASSED TO NEXT GENERATION – THE TRAIT IS PASSED TO NEXT GENERATION – BUT SKIPPED A GENERATION IT IS RECESSIVE- BUT SKIPPED A GENERATION IT IS RECESSIVE- IF THE PARENTS WERE NORMAL AND HAD A IF THE PARENTS WERE NORMAL AND HAD A CHILD WITH THE TRAIT IT IS RECESSIVECHILD WITH THE TRAIT IT IS RECESSIVE

Autosomal pedigree chartAutosomal pedigree chart

Sex-linked pedigreeSex-linked pedigree

XII. Genetic Diseases - ExamplesXII. Genetic Diseases - Examples

XII. GENETIC DISEASESXII. GENETIC DISEASES

A. Dominant Single AlleleA. Dominant Single Allele 1. Huntingtons1. Huntingtons 2. Dwarfism2. Dwarfism 3. Cataracts3. Cataracts 4. Polydactyl4. Polydactyl

GENETIC DISEASESGENETIC DISEASES

B. Recessive Single AlleleB. Recessive Single Allele 1. Albinism1. Albinism 2. PKU (phenylketonuria)2. PKU (phenylketonuria) 3. Deafness3. Deafness 4. Sickle Cell Anemia4. Sickle Cell Anemia 5. Cystic Fibrosis5. Cystic Fibrosis 6. Tay Sachs6. Tay Sachs

GENETICS DISEASESGENETICS DISEASES

C. X-LinkedC. X-Linked 1. Colorblindness1. Colorblindness 2. Hemophilia2. Hemophilia 3. Muscular Dystrophy3. Muscular Dystrophy 4. Icthyosis4. Icthyosis

Genetic Diseases – Linked GenesGenetic Diseases – Linked Genes

Linked Genes and Genetic DiseasesLinked Genes and Genetic Diseases

Inheritance of Recessive Inheritance of Recessive Genetic DiseasesGenetic Diseases

Inheritance of Genetic DiseasesInheritance of Genetic Diseases

Normal Red Blood Cells Normal Red Blood Cells and Sickle Cellsand Sickle Cells

D. Sex-Linked Genetic Diseases D. Sex-Linked Genetic Diseases X-Linked (Diseases on X chromosome)X-Linked (Diseases on X chromosome)

Hemophilia Inheritance Hemophilia Inheritance Sex-Linked Genetic DiseaseSex-Linked Genetic Disease

SO WHERE THE VARIATION SO WHERE THE VARIATION EVOLUTION ACTS UPON COME EVOLUTION ACTS UPON COME

FROM???FROM???

Variation in PopulationsVariation in PopulationsC. Genetic Sources of VariationC. Genetic Sources of Variation

1. 1. MutationsMutationsa) a specific gene mutates in a) a specific gene mutates in 1/10,0000 gametes1/10,0000 gametesb) thousands of genes in each gameteb) thousands of genes in each gametec) some mutations in every zygotec) some mutations in every zygoted) most mutations are recessived) most mutations are recessive

IV. Variation in PopulationsIV. Variation in PopulationsC. Genetic Sources of VariationC. Genetic Sources of Variation

2. 2. Genetic Recombination Genetic Recombination a) random meeting of sperm and egga) random meeting of sperm and egg b) crossing overb) crossing over c) independent assortment c) independent assortment

What can What can decreasedecrease variation in a population? variation in a population? 1. 1. Genetic Drift Genetic Drift a) occurs in small populationsa) occurs in small populations b) elimination of some genes by chanceb) elimination of some genes by chance c) may decrease variationc) may decrease variation

IV. Variation in PopulationsIV. Variation in PopulationsC. Genetic Sources of VariationC. Genetic Sources of Variation

2. 2. Non-random Mating Non-random Mating

3. Fecundity selection/ Mortality selection 3. Fecundity selection/ Mortality selection Some organisms with certain traits reproduce more or survive better to Some organisms with certain traits reproduce more or survive better to

reproductive age than others.reproductive age than others.

What can increase variation in a population?What can increase variation in a population?

1. Migration (Gene Flow)- 1. Migration (Gene Flow)- mating with members of different mating with members of different populations).populations).

a) a) immigrationimmigration- movement into an - movement into an area or population area or population b) b) emigrationemigration – movement out of an – movement out of an area or populationarea or population

2. Random mating2. Random mating

H-W EquilibriumH-W Equilibrium

The Hardy-Weinberg law of genetic The Hardy-Weinberg law of genetic equilibrium provides a mathematical model equilibrium provides a mathematical model for studying evolutionary changes in allelic for studying evolutionary changes in allelic frequency within a population. A frequency within a population. A population in population in HardyHardy--Weinberg Weinberg equilibriumequilibrium shows shows no changeno change. .

ANIMATIONhttp://zoology.okstate.edu/zoo_lrc/biol1114/tutorials/Flash/life4e_15-6-OSU.swf

IV. Variation in PopulationsIV. Variation in PopulationsD. Genetic EquilibriumD. Genetic Equilibrium

1. 1. Hardy-Weinberg PrincipleHardy-Weinberg Principle a) a) allele frequenciesallele frequencies are stable across generations are stable across generations b) sexual reproduction alone does notb) sexual reproduction alone does not affect genetic equilibriumaffect genetic equilibrium

2. Conditions Necessary 2. Conditions Necessary a) no immigration a) no immigration b) no mutations b) no mutations c) no natural selection c) no natural selection d) large populationsd) large populations e) random matinge) random mating f) everyone produces the same f) everyone produces the same

number number of offspringof offspring CONCEPTS OF H-W EQUILBRIUMCONCEPTS OF H-W EQUILBRIUM

http://www.phschool.com/science/biology_place/labbench/lab8/http://www.phschool.com/science/biology_place/labbench/lab8/concepts.htmlconcepts.html

IV. Variation in PopulationsIV. Variation in PopulationsE. Mathematics/Hardy WeinbergE. Mathematics/Hardy Weinberg

1. 1. gene poolgene pool - all the genes in a population - all the genes in a population 2. 2. allele frequencyallele frequency - % occurrence of a - % occurrence of a specific allele in a populationspecific allele in a population3. 3. phenotype frequencyphenotype frequency - % occurrence of an - % occurrence of an

individual in a population with a traitindividual in a population with a trait4. 4. genotype frequencygenotype frequency - % occurrence of - % occurrence of individuals in a population with a specific individuals in a population with a specific genotype genotype

IV. Variation in PopulationsIV. Variation in PopulationsE. Mathematics/Hardy WeinbergE. Mathematics/Hardy Weinberg

5. applying mathematics5. applying mathematics

a) a) pp = frequency of the dominant allele = frequency of the dominant allele qq = frequency of the recessive allele = frequency of the recessive allele

b) b) p + q = 1p + q = 1c) c) pp22 + 2pq + q + 2pq + q22 = 1 = 1

IV. Variation in PopulationsIV. Variation in PopulationsE. Mathematics/Hardy WeinbergE. Mathematics/Hardy Weinberg

d) d) qq22 = recessive phenotype/genotype = recessive phenotype/genotype frequencyfrequency

pp22 +2pq+2pq = dominant phenotype = dominant phenotype frequencyfrequencypp22 = pure dominant genotype frequency = pure dominant genotype frequency2pq2pq= heterozygous genotype frequency= heterozygous genotype frequency

Problems:Problems:

In a population of 100 cats, 84 are black In a population of 100 cats, 84 are black and 16 are white.and 16 are white.

What is the phenotype frequency for white What is the phenotype frequency for white cats? Black cats?cats? Black cats?What is the recessive allele frequency? What is the recessive allele frequency? What is the dominant frequency?What is the dominant frequency?

HW problemHW problem

Given an allele frequency for the tall allele Given an allele frequency for the tall allele (T=.60), calculate the phenotype (T=.60), calculate the phenotype frequencies for tall and short plants.frequencies for tall and short plants.

Short phenotype frequency?Short phenotype frequency?Tall phenotype frequency?Tall phenotype frequency?

More problems…More problems…

If 4.0% of seeds are yellow and 96% are If 4.0% of seeds are yellow and 96% are green (Green is dominant). Calculate the green (Green is dominant). Calculate the allele frequencies for the yellow allele and allele frequencies for the yellow allele and the allele for green.the allele for green.

Yellow allele frequency?Yellow allele frequency?Green allele frequency?Green allele frequency?

Even more problems….Even more problems….

25% of an animal population has blue 25% of an animal population has blue eyes (recessive) and 75% have brown eyes (recessive) and 75% have brown eyes. What is the allele frequency for the eyes. What is the allele frequency for the blue (b) allele and for the brown (B) allele?blue (b) allele and for the brown (B) allele?

Recessive allele frequency?Recessive allele frequency?Dominant allele frequency?Dominant allele frequency?

Evolution Revisited…Evolution Revisited…

1. 1. EvolutionEvolution may be defined as may be defined as a) change in a) change in genetic materialgenetic material in a in a populationpopulation b) change in b) change in allele frequencyallele frequency in a in a population population c) change in c) change in genotype/phenotype ratiogenotype/phenotype ratio d) d) speciationspeciation

SUMMARYSUMMARY

THE ENVIRONMENT DRIVES THE ENVIRONMENT DRIVES EVOLUTION TO FAVOR CERTAIN EVOLUTION TO FAVOR CERTAIN VARIATIONS OF ORGANISMS (no one VARIATIONS OF ORGANISMS (no one best way to be all the time). THESE best way to be all the time). THESE VARIATIONS ARISE FROM MUTATIONS VARIATIONS ARISE FROM MUTATIONS AND MEIOSIS AND GET PASSED ON AND MEIOSIS AND GET PASSED ON THROUGH REPRODUCTION AND THROUGH REPRODUCTION AND HEREDITY.HEREDITY.