question of the day dec 20 a nucleotide does not contain a nucleotide does not contain a. a 5-c...

Question of the Day DEC 20Question of the Day DEC 20

A nucleotide does not containA nucleotide does not contain

A. a 5-C sugarA. a 5-C sugarB. polymeraseB. polymeraseC. a nitrogenous baseC. a nitrogenous baseD. a phosphate groupD. a phosphate group

DO NOW DEC 20DO NOW DEC 20

How is genetic information stored within How is genetic information stored within our cells?our cells?

DO NOW ANSWERED DEC 20DO NOW ANSWERED DEC 20

Humans have 46 chromosomes.Humans have 46 chromosomes.Chromosomes are made of DNA.Chromosomes are made of DNA.Each chromosome contains genes that Each chromosome contains genes that

code for specific traits.code for specific traits.Genetic Blueprints.Genetic Blueprints.

AGENDA Dec 20AGENDA Dec 20

Big Question: What did scientists discover about Big Question: What did scientists discover about the relationship between genes and DNA?the relationship between genes and DNA?

1. DO NOW1. DO NOW 2. The discovery of DNA2. The discovery of DNA 3. Early Experiments3. Early Experiments 4. Closing Thoughts and Review4. Closing Thoughts and Review 5. HOMEWORK: READ Section 12-2 and Guided 5. HOMEWORK: READ Section 12-2 and Guided

Reading QuestionsReading Questions

Decoding our GenesDecoding our Genes

We use letters, punctuation, and symbols We use letters, punctuation, and symbols to form words, write, and communicate.to form words, write, and communicate.

sala lekcyjna sala lekcyjna

What do these letters mean?What do these letters mean?

Decoding our GenesDecoding our Genes

““Class room” in PolishClass room” in Polish

Words do not have meaning to us unless Words do not have meaning to us unless we can understand the language.we can understand the language.

Question of the DAY DEC 23Question of the DAY DEC 23

In prokaryotes, DNA molecules are In prokaryotes, DNA molecules are located in thelocated in the

A. ribosomesA. ribosomesB. nucleusB. nucleusC. cytoplasmC. cytoplasmD. mitochondriaD. mitochondria

AGENDA Dec 23AGENDA Dec 23

Big Question: What did scientists discover Big Question: What did scientists discover about existence of DNA?about existence of DNA?

1. Question of the DAY1. Question of the DAY 2. The discovery of DNA2. The discovery of DNA 3. Early Experiments3. Early Experiments 4. PRESENTATIONS4. PRESENTATIONS 5. Closing Thoughts and Review5. Closing Thoughts and Review

The Universal Language of LifeThe Universal Language of Life

In this chapter, we will explore…In this chapter, we will explore…Early scientific research leading to the Early scientific research leading to the

discovery of DNA.discovery of DNA.The processes responsible for copying The processes responsible for copying

DNA and protein synthesis.DNA and protein synthesis.ReplicationReplicationTranscriptionTranscriptionTranslationTranslation

Chapter 12: DNA and RNAChapter 12: DNA and RNA

12-1: Discovering DNA12-1: Discovering DNA

Frederick Griffith (1928)Frederick Griffith (1928)tried to find better ways to fight tried to find better ways to fight

pneumoniapneumoniaisolated 2 types of bacteria that cause isolated 2 types of bacteria that cause

pneumoniapneumoniasmooth: smooth:

deadly formdeadly formrough: rough:

nondeadly formnondeadly form

Griffith’s ExperimentGriffith’s Experiment

R-strain (Rough): NonvirulentR-strain (Rough): NonvirulentS-strain (Smooth): VirulentS-strain (Smooth): VirulentHeat Killed S-Strain: NonvirulentHeat Killed S-Strain: Nonvirulent

R-strain + Heat Killed S-strain: ???R-strain + Heat Killed S-strain: ???

Griffith’s ResultsGriffith’s Results

What killed the mouse?What killed the mouse?

Why did the Why did the RR-strain and heat killed -strain and heat killed SS--strain combination kill the mouse?strain combination kill the mouse?

TransformationTransformationwhen one type of bacteria is changed into when one type of bacteria is changed into

anotheranother realized some molecule changed harmless realized some molecule changed harmless

rough bacteria into deadly smooth bacteriarough bacteria into deadly smooth bacteria

Question of the DAY Jan 2Question of the DAY Jan 2

The process that changes one strain of The process that changes one strain of bacteria into another strain is calledbacteria into another strain is called

A. TranscriptionA. TranscriptionB. TranslationB. TranslationC. TransformationC. TransformationD. ReplicationD. Replication

DO NOW Jan 2DO NOW Jan 2

Cross a heterozygous long clawed, Cross a heterozygous long clawed, homozygous dominant spotted coat jaguar homozygous dominant spotted coat jaguar with a short clawed, black coat jaguar.with a short clawed, black coat jaguar.

What are the chances of having a short-What are the chances of having a short-clawed, spotted coat jaguar?clawed, spotted coat jaguar?

SAMPLE TEST QuestionSAMPLE TEST Question4 minutes to solve this problem. GO!4 minutes to solve this problem. GO!

DO NOW Answer Jan 2 DO NOW Answer Jan 2

cs cs cs cs

CS CcSs CcSs CcSs CcSs

CS CcSs CcSs CcSs CsSs

cS ccSs ccSs ccSs ccSs

cS ccSs ccSs ccSs ccSs

AGENDA Jan 2AGENDA Jan 2 BIG Question: What is the relationship between BIG Question: What is the relationship between

genes and DNA?genes and DNA?

1. Question and DO NOW1. Question and DO NOW 2. Finish Section 12-1 History of 2. Finish Section 12-1 History of

DNA/ExperimentsDNA/Experiments 3. Critical Thinking Response3. Critical Thinking Response 4. Review and HOMEWORK: Guided 4. Review and HOMEWORK: Guided

Reading Packet 12-2Reading Packet 12-2 5. History of DNA Quiz on MONDAY Jan 65. History of DNA Quiz on MONDAY Jan 6

Oswald Avery (1944)Oswald Avery (1944)wanted to find out wanted to find out

which molecule which molecule caused caused transformationtransformation

found transformation found transformation was blocked when was blocked when DNA was destroyedDNA was destroyed

concluded genes concluded genes are made up of DNAare made up of DNA

DNA is the Transforming FactorDNA is the Transforming Factor

Avery’s ExperimentAvery’s Experiment

Treated the Treated the RR-strain and heat killed -strain and heat killed SS--strain bacteria with enzymes designed to strain bacteria with enzymes designed to destroy proteins and DNA.destroy proteins and DNA.

Proteins were destroyed Proteins were destroyed → → mouse diedmouse diedDNA was destroyed DNA was destroyed → → mouse livedmouse lived

Hershey and Chase (1952)Hershey and Chase (1952)

usedused bacteriophages: bacteriophages: type of virus that infects type of virus that infects bacteriabacteriacontains protein and contains protein and

DNADNA

usedused radioactive radioactive isotopesisotopes

Hershey and Chase’s ResultsHershey and Chase’s Resultsused radioactive isotopes to label the DNA used radioactive isotopes to label the DNA

and protein in a bacteriophageand protein in a bacteriophage labeled DNA with phosphorus-32labeled DNA with phosphorus-32 labeled protein with sulfur-35labeled protein with sulfur-35allowed bacteriophage to infect a bacteriumallowed bacteriophage to infect a bacterium found bacterium was made radioactive by found bacterium was made radioactive by

phosphorus-32phosphorus-32concluded genetic material of bacteriophage concluded genetic material of bacteriophage

must be DNAmust be DNA

Hershey and ChaseHershey and Chase

Hershey and Chase AnimationHershey and Chase Animation

http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120076/bio21.swf::Hershey%20and%20Chase%20Experiment

Chapter 12-1: Quiz Jan 6Chapter 12-1: Quiz Jan 6

History of DNA QUIZHistory of DNA QUIZ

You have 15 minutes to complete the quiz.You have 15 minutes to complete the quiz.

AGENDA Jan 6AGENDA Jan 6

Big Question: How did the work of early scientists Big Question: How did the work of early scientists lead to the discovery of DNA?lead to the discovery of DNA?

1. Question of the Day and DO NOW1. Question of the Day and DO NOW 2. Structure of DNA2. Structure of DNA 3. Review chromatin and chromosomes3. Review chromatin and chromosomes 4. Chargaff, Franklin, Watson and Crick4. Chargaff, Franklin, Watson and Crick 5. Closing Thoughts and Review5. Closing Thoughts and Review

12-2: DNA Structure and Replication12-2: DNA Structure and Replication DNADNA

deoxyribonucleic deoxyribonucleic acidacid

made of polymers made of polymers of nucleotides, of nucleotides, which have three which have three partspartsphosphate groupphosphate groupnitrogenous basenitrogenous base5-carbon sugar: 5-carbon sugar:

deoxyribosedeoxyribose

DNA and ChromosomesDNA and Chromosomes genetic information is genetic information is

on chromosomeson chromosomes chromosomes made chromosomes made

up of chromatinup of chromatin chromatin consists of chromatin consists of

DNA and proteinDNA and protein histones:histones: class of class of

proteins that bind proteins that bind directly to DNAdirectly to DNA form tiny particles form tiny particles

called called nucleosomesnucleosomes

help to unfold and help to unfold and package DNApackage DNA

Types of NucleotidesTypes of Nucleotides

adenine (A)adenine (A)cytosine (C)cytosine (C)guanine (G)guanine (G) thymine (T)thymine (T)nucleotides nucleotides

are different are different because of the because of the base they base they containcontain

Chargaff’s Rules (1950)Chargaff’s Rules (1950)

amounts of adenine and thymine were the amounts of adenine and thymine were the samesame

amounts of cytosine and guanine were the amounts of cytosine and guanine were the samesame

Rosalind Franklin (1951)Rosalind Franklin (1951)

used used x-ray diffraction:x-ray diffraction: when an x-ray when an x-ray beam is aimed at a sample and is then beam is aimed at a sample and is then scattered and recorded on filmscattered and recorded on film

unlocked clues to DNA structureunlocked clues to DNA structure

Rosalind FranklinRosalind FranklinThe Unsung HeroThe Unsung Hero

http://www.youtube.com/watch?v=y6k1jpQIlEU

Watson and CrickWatson and Crick created a model for the created a model for the

structure of DNAstructure of DNA contained two strandscontained two strands twisted like a helixtwisted like a helix double helixdouble helix bonds between bonds between

nitrogenous bases hold nitrogenous bases hold strands togetherstrands together

base pairsbase pairsA-TA-TC-GC-G

strands are strands are complimentarycomplimentary


Hershey and Chase labeled proteins of Hershey and Chase labeled proteins of bacteriophages withbacteriophages with

A. Phosphorus 32A. Phosphorus 32B. Phosphorus 35B. Phosphorus 35C. Sulfur 32C. Sulfur 32D. Sulfur 35D. Sulfur 35


How are our cells similar to a library?How are our cells similar to a library?

DO NOW ANSWERED Jan 7DO NOW ANSWERED Jan 7

Our cells store genetic information in our Our cells store genetic information in our chromosomes.chromosomes.

Chromosomes are similar to bookshelves.Chromosomes are similar to bookshelves. The genes found on our chromosomes are like The genes found on our chromosomes are like

books on a shelf.books on a shelf. Each gene is organized on a specific Each gene is organized on a specific

chromosome.chromosome. Information on genes are read by the cell much Information on genes are read by the cell much

like we would read a book.like we would read a book.


Big Question: How did the work of early scientists Big Question: How did the work of early scientists lead to the discovery of DNA?lead to the discovery of DNA?

1. Question of the Day and DO NOW1. Question of the Day and DO NOW 2. Hand in your homework2. Hand in your homework 3. Franklin, Watson, and Crick3. Franklin, Watson, and Crick 4. DNA Replication4. DNA Replication 5. Closing Thoughts and Review5. Closing Thoughts and Review

ReplicationReplication Process in which DNA is Process in which DNA is

copiedcopied

Molecule separates into Molecule separates into two strands.two strands.

Each template strand Each template strand produces a new produces a new complementary strand.complementary strand.

Requires DNA PolymeraseRequires DNA Polymerase

DNA ReplicationDNA Replication

Double helix structure explained how DNA Double helix structure explained how DNA is copied.is copied.

Each strand contains all of the information Each strand contains all of the information needed to construct the other half.needed to construct the other half.

Rules of base pairing: Rules of base pairing: A = TA = T G = CG = C

DNA PolymeraseDNA Polymerase

Enzyme that joins individual nucleotides Enzyme that joins individual nucleotides together to produce a DNA molecule.together to produce a DNA molecule.

““Proofreads” new DNA strands for errors.Proofreads” new DNA strands for errors.

Copy the following strand of DNACopy the following strand of DNAATTCGGTGAATTCGGTGA


Which pair of molecules are necessary for Which pair of molecules are necessary for DNA replication?DNA replication?

A. Rubisco and ChlorophyllA. Rubisco and ChlorophyllB. Helicase and RNA PolymeraseB. Helicase and RNA PolymeraseC. DNA Polymerase and RNA PolymeraseC. DNA Polymerase and RNA PolymeraseD. DNA Polymerase and HelicaseD. DNA Polymerase and Helicase


Explain how 6 feet of DNA can be packed Explain how 6 feet of DNA can be packed into the nucleus of a microscopic cell. into the nucleus of a microscopic cell.


DNA is packed into our cells as chromatin.DNA is packed into our cells as chromatin.

Special proteins called histones bind to Special proteins called histones bind to the DNA molecules.the DNA molecules.

Particles called nucleosomes are formed Particles called nucleosomes are formed with histones which help to tightly coil up with histones which help to tightly coil up DNA…. DNA…. SupercoilingSupercoiling


1. Question of the Day and DO NOW1. Question of the Day and DO NOW2. Finish Creating your Code Activity2. Finish Creating your Code Activity

Work on Guided reading Packet 12-2Work on Guided reading Packet 12-23. What is RNA? Section 12-33. What is RNA? Section 12-34. Transcription4. Transcription5. Closing Thoughts and Homework5. Closing Thoughts and Homework

DNA ReplicationDNA ReplicationA DNA molecule has 2 A DNA molecule has 2

strands. strands. 5 - 3 strand 5 - 3 strand 3 - 5 strand3 - 5 strand

Each new strand copied Each new strand copied is complementary to its is complementary to its parent (template) parent (template) strand.strand.

Replication in OrganismsReplication in Organisms

PROKARYOTESPROKARYOTES Starts at a single pointStarts at a single point

Two directionsTwo directions

Copies entire chromosomeCopies entire chromosome

In what part of the cell does In what part of the cell does replication occur?replication occur?

EUKARYOTESEUKARYOTES Occurs in many different Occurs in many different

places along DNA moleculeplaces along DNA molecule

Proceeds in two directionsProceeds in two directions

Copies entire chromosomeCopies entire chromosome

In what part of the cell does In what part of the cell does replication occur?replication occur?

12-3: RNA12-3: RNA decodes the genetic decodes the genetic

information in DNAinformation in DNAalso a nucleic acidalso a nucleic aciddiffers from DNA in 3 differs from DNA in 3

wayswayssugar is ribosesugar is ribosesingle-strandedsingle-strandedcontains uracil (U) contains uracil (U)

instead of thymineinstead of thymine

TranscriptionTranscription process by which mRNA process by which mRNA

molecules are mademolecules are made DNA is a template for mRNADNA is a template for mRNA RNA polymerase:RNA polymerase: an enzyme an enzyme

that binds directly to a molecule that binds directly to a molecule of DNA of DNA produces a strand of RNA produces a strand of RNA

AACT AACT UUGA UUGA begins and stops begins and stops

transcription at special start transcription at special start and stop sequences on the and stop sequences on the DNADNA


During DNA Replication, a template strand During DNA Replication, a template strand is also known as a is also known as a

A. complementary strandA. complementary strandB. copied strandB. copied strandC. sister strandC. sister strandD. parent strandD. parent strand


1. Copy the following strand of DNA…1. Copy the following strand of DNA…A T T G G C T C C A T G CA T T G G C T C C A T G C

2. Transcribe your copied strand from #1.2. Transcribe your copied strand from #1.


ReplicationReplication1. 1. A T T G G C T C C A T G CA T T G G C T C C A T G C T A A C C G A G G T A C GT A A C C G A G G T A C G

TranscriptionTranscription2. 2. T A A C C G A G G T A C GT A A C C G A G G T A C G A U U G G C U C C A U G C A U U G G C U C C A U G C


BIG Question: How are proteins made BIG Question: How are proteins made using RNA?using RNA?

1. DO NOW1. DO NOW2. RNA, Translation, and Protein 2. RNA, Translation, and Protein

SynthesisSynthesis3. Transcription/Translation Problems3. Transcription/Translation Problems4. Review Key Concepts and Homework4. Review Key Concepts and Homework

Forms of RNAForms of RNA mRNA: messenger RNA mRNA: messenger RNA

carries copies of carries copies of instructions for the instructions for the assembly of amino acids assembly of amino acids into polypeptidesinto polypeptides

rRNA: ribosomal RNA rRNA: ribosomal RNA makes up ribosomes makes up ribosomes

where proteins are madewhere proteins are made

tRNA: transfer RNA tRNA: transfer RNA

transfers one amino transfers one amino acid after another to acid after another to the ribosomethe ribosome

Genes in PiecesGenes in PiecesmRNA is editedmRNA is edited

parts are parts are discarded discarded called called intronsintrons

exons:exons: remaining remaining parts that get parts that get spliced spliced together and together and are expressedare expressed

Genetic CodeGenetic Code

amino acids make up amino acids make up polypeptides which polypeptides which make up proteinsmake up proteinsorder of amino acids order of amino acids

determine proteindetermine protein instructions in DNA instructions in DNA

specify the order the specify the order the amino acids are put amino acids are put togethertogether

called the called the genetic genetic codecode

Reading the CODON ChartReading the CODON Chart

Decoding the Genetic CodeDecoding the Genetic Code nucleotides in mRNA can code for 20 different nucleotides in mRNA can code for 20 different

amino acidsamino acids

read in groups of three called read in groups of three called codons – three codons – three nucleotides that specify a specific amino acidnucleotides that specify a specific amino acid

mRNA sequence mRNA sequence AAACACGGUAAACACGGU

read as 3 codons read as 3 codons AAAAAA--CACCAC--GGUGGU Each codon Each codon

amino acid amino acid lysine lysine--histidinehistidine--glycineglycine

CodonsCodons more than one codon more than one codon

can specify the same can specify the same amino acidamino acid

AUG codonAUG codon start signal or start signal or

initiator codoninitiator codon codes for codes for

methionine, which is methionine, which is the first amino acidthe first amino acid

UAA, UAG, UGA UAA, UAG, UGA codonscodons stop signalsstop signals

Question of the Day Jan 10Question of the Day Jan 10

Which type of RNA is responsible for the Which type of RNA is responsible for the assembly of amino acids into a assembly of amino acids into a polypeptide?polypeptide?

A. tRNAA. tRNAB. rRNAB. rRNAC. dRNAC. dRNAD. mRNAD. mRNA


1. Copy the following strand of DNA…1. Copy the following strand of DNA…A A A A T G G C T C C A T G C T G AA A A A T G G C T C C A T G C T G A

2. Transcribe your copied strand from #1.2. Transcribe your copied strand from #1.

3. Translate the section of mRNA from #2.3. Translate the section of mRNA from #2.

DO NOW ANSWERED Jan DO NOW ANSWERED Jan 1010

ReplicationReplication1. 1. A A A A T G G C T C C A T G C T G AA A A A T G G C T C C A T G C T G A T T T T A C C G A G G T A C G A C TT T T T A C C G A G G T A C G A C T

TranscriptionTranscription2. 2. T T T T A C C G A G G T A C G A C TT T T T A C C G A G G T A C G A C T A A A A U G G C U C C A U G C U G A A A A A U G G C U C C A U G C U G A

DO NOW Answered Jan 10DO NOW Answered Jan 10

3. Translation3. Translation A A A A U G G C U C C A U G C U G A A A A A U G G C U C C A U G C U G A

AUG AUG GCUGCU CCACCA UGCUGC UGA UGA METMET – – ALAALA – PRO – – PRO – CYSCYS

AGENDA Jan 10AGENDA Jan 10BIG Question: How is a protein produced BIG Question: How is a protein produced

using RNA?using RNA?1. Question of the Day and DO NOW1. Question of the Day and DO NOW2. Translation2. Translation3. Transcription/Translation Practice 3. Transcription/Translation Practice

ProblemsProblems4. Homework and Review4. Homework and ReviewQUIZ on MONDAY!!!!!QUIZ on MONDAY!!!!!CH 12 TEST – NEXT WEEK!!!!!!!!!!!CH 12 TEST – NEXT WEEK!!!!!!!!!!!

TranslationTranslation The decoding of mRNA into a polypeptide chain The decoding of mRNA into a polypeptide chain

(protein).(protein). happens in cytoplasmhappens in cytoplasm rRNA in ribosomes reads codons in mRNArRNA in ribosomes reads codons in mRNA tRNA brings proper amino acids to form proteintRNA brings proper amino acids to form protein

Translation in Four StepsTranslation in Four StepsRead your textbook: Pages 304 and 305Read your textbook: Pages 304 and 305

STEP A: Messenger RNA STEP A: Messenger RNA mRNA is transcribed from DNAmRNA is transcribed from DNA

In nucleus In nucleus released into cytoplasm released into cytoplasm

Attaches to a ribosomeAttaches to a ribosome

STEP B: Transfer RNASTEP B: Transfer RNA Each tRNA has an anitcodon (complementary Each tRNA has an anitcodon (complementary

to codon on mRNA).to codon on mRNA). Codon = AAACodon = AAA Anticodon = UUUAnticodon = UUU

Translation in Four StepsTranslation in Four Steps STEP C: Polypeptide Assembly LineSTEP C: Polypeptide Assembly Line Ribosome joins the amino acids togetherRibosome joins the amino acids together After an amino acid is joined to the chain, the After an amino acid is joined to the chain, the

tRNA exits the ribosome.tRNA exits the ribosome. Another tRNA delivers its amino acid to the Another tRNA delivers its amino acid to the

RibosomeRibosome

STEP D: Completing the PolypeptideSTEP D: Completing the Polypeptide The Ribosome moves along the mRNA.The Ribosome moves along the mRNA.

Translation STOPS when it reads a STOP Codon.Translation STOPS when it reads a STOP Codon. Polypeptide is complete Polypeptide is complete folds into a Protein folds into a Protein

Translation AnimationTranslation Animation

http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter3/animation__how_translation_works.html


How does tRNA help in the decoding of How does tRNA help in the decoding of mRNA?mRNA?

DO NOW ANSWEREDDO NOW ANSWERED

tRNA contains a complementary codon to tRNA contains a complementary codon to the one found on the mRNA.the one found on the mRNA.

The codon found on tRNA is called an The codon found on tRNA is called an anti-codon.anti-codon.

tRNA carries a specific amino acid to tRNA carries a specific amino acid to ribosomes where they are joined together ribosomes where they are joined together to form a polypeptide.to form a polypeptide.

CODON CODON UAUUAU ANTICODON ANTICODON AUAAUA


The anticodon carried on tRNA for the The anticodon carried on tRNA for the codon CAG iscodon CAG is

A. CUGA. CUGB. GTCB. GTCC. GACC. GACD. GUCD. GUC


Big Question: How do mutations affect cells?Big Question: How do mutations affect cells?

1. Question of the Day1. Question of the Day 2. Review Translation Problems2. Review Translation Problems 3. Mutations3. Mutations 4. Review Key Concepts4. Review Key Concepts 5. HOMEWORK – 12-4 and 12-5 Guided 5. HOMEWORK – 12-4 and 12-5 Guided

Reading Packet (Graded)Reading Packet (Graded) STUDY for QUIZ Tomorrow - TranslationSTUDY for QUIZ Tomorrow - Translation

12-4 Mutations12-4 Mutations

Changes in genetic material.Changes in genetic material. Gene Mutations occur within a single gene.Gene Mutations occur within a single gene. READ Pages 307 - 308READ Pages 307 - 308

POINT Mutation POINT Mutation – changes in one or a few – changes in one or a few nucleotidesnucleotides

Substitutions – affect a single amino acidSubstitutions – affect a single amino acid Insertions – can be more damagingInsertions – can be more damaging Deletions – can be more damagingDeletions – can be more damaging

MutationsMutations

Frameshift MutationFrameshift Mutation – reading frame of codons are – reading frame of codons are shiftedshifted

May affect all amino acids in an mRNA sequenceMay affect all amino acids in an mRNA sequence Protein may not be able to perform its functionProtein may not be able to perform its function

Chromosomal Mutation Chromosomal Mutation – changes number or – changes number or structure of chromosomes.structure of chromosomes.

Change locations of genes and change numbers of Change locations of genes and change numbers of copies of genes.copies of genes.

MutationsMutations

Mutations are a source of genetic variation.Mutations are a source of genetic variation.

Some mutations are beneficial to organisms.Some mutations are beneficial to organisms.

PolyploidyPolyploidy is a condition where organisms have is a condition where organisms have extra sets of chromosomes.extra sets of chromosomes.

Polyploid plants are stronger and larger than Polyploid plants are stronger and larger than diploid ones.diploid ones.

Bananas, strawberries, citrus fruitsBananas, strawberries, citrus fruits


Big Question: How do mutations affect cells?Big Question: How do mutations affect cells?

1. QUIZ on Translation1. QUIZ on Translation 2. Regulating Gene Expression2. Regulating Gene Expression 3. Review Key Concepts3. Review Key Concepts 4. STUDY GUIDES – Homework Check4. STUDY GUIDES – Homework Check STUDY for TEST on ThursdaySTUDY for TEST on Thursday

12-5: Controlling Gene Expression12-5: Controlling Gene Expression

cells regulate gene transcriptioncells regulate gene transcription they do not always need a gene’s productthey do not always need a gene’s producta transcribed gene is said to be expressed a transcribed gene is said to be expressed

or turned onor turned ona gene that is not being transcribed is offa gene that is not being transcribed is off

Gene ExpressionGene Expression promoterpromoter: binding site for : binding site for

RNA polymeraseRNA polymerase moves along DNAmoves along DNA finds the first genefinds the first gene starts transcriptionstarts transcription

repressor:repressor: DNA binding DNA binding proteinprotein blocks a gene’s blocks a gene’s

transcriptiontranscription operator:operator: special region of special region of

DNA DNA repressor binds hererepressor binds here RNA polymerase can not RNA polymerase can not

move past operatormove past operator

Lac OperonLac Operon TEXTBOOK – Pages 309-310TEXTBOOK – Pages 309-310 Operon Operon – group of genes that operate together.– group of genes that operate together.

Found in the bacterium Found in the bacterium E. coliE. coli

Lac genes are 3 genesLac genes are 3 genes Needed to break down lactose for a food source.Needed to break down lactose for a food source.

Requires lactose to enter the cell.Requires lactose to enter the cell. Lactose binds repressor and activates lac genes.Lactose binds repressor and activates lac genes.

RNA Polymerase free to move and begin transcriptionRNA Polymerase free to move and begin transcription

Eukaryotic Gene RegulationEukaryotic Gene Regulation Most genes controlled individuallyMost genes controlled individually

Contain complex regulatory sequencesContain complex regulatory sequences

TATA Box TATA Box – short sequence of TATATA or TATAAA– short sequence of TATATA or TATAAA Marks a point along DNA just before spot to begin Marks a point along DNA just before spot to begin

transcription.transcription. Makes cell specialization possibleMakes cell specialization possible

Only a small number of genes expressed in each type of Only a small number of genes expressed in each type of cellcell

Skin cell versus Skin cell versus liver cell liver cell versus versus blood cellblood cell

Development and DifferentiationDevelopment and Differentiation

Gene expression important in development of Gene expression important in development of complex organisms.complex organisms.

Differentiation is the specific growth of a cell’s Differentiation is the specific growth of a cell’s structure and function.structure and function.Occurs during embryonic growth.Occurs during embryonic growth.

HOX Genes HOX Genes control this process in the embryo.control this process in the embryo. Mutations can completely change growth in organism.Mutations can completely change growth in organism.

HOX GenesHOX Genes In the fruit fly, a mutation can replace the In the fruit fly, a mutation can replace the

antennae with legs growing on its head.antennae with legs growing on its head.

HOX genes very similar in all organisms.HOX genes very similar in all organisms.Due to common ancestry between organismsDue to common ancestry between organisms

Gene controlling eye growth in mouse Gene controlling eye growth in mouse inserted into the “knee” of a fruit flyinserted into the “knee” of a fruit fly An eye grew on the leg of this fruit fly.An eye grew on the leg of this fruit fly.

These two animals have not shared a common These two animals have not shared a common ancestor in 600 million years.ancestor in 600 million years.

question of the day dec 20 a nucleotide does not contain a nucleotide does not contain a. a 5-c...

Documents