2/11 Period 4 and 5 sit in new seats Short FRQ – read/outline together first, then 6 minute write Review what movie has covered so far – from which chapters?

2/11

• Period 4 and 5 sit in new seats• Short FRQ – read/outline together first, then 6

minute write• Review what movie has covered so far – from

which chapters?• Continue What Darwin Never Knew (I check labs

during)Homework – Chapter 24 and 25 notes & concept checks due

Thurs. and online due next Tuesday..

Agenda 2/12

• Review what movie covered

• Continue What Darwin Never Knew (I check the rest of the labs)

Homework –

Chapter 24 and 25 notes & concept checks due Thursday and online due next Tuesday.

Agenda 2/13

• Finish What Darwin Never Knew

• Start Ch. 22-25 Highlights and practice questions

Homework -

Chapter 24 and 25 notes & concept checks due tomorrow and online due next Tuesday.

Agenda 2/14• Wrap up discussion of video – Sticklebacks and yesterday’s topics

(4 research studies about human evolution) and next slides about switches – 20 min

• Highlights Ch. 22-25 – 25 min• I check Ch. 24 and 25 notes while you do slides

Homework – Chapter 24 and 25 online due next Tuesday.Print Hardy-Weinberg lab packet from website for Tues.Ch. 22 Hardy Weinberg due next Thursday with quiz FridayChapter 26(parts 1,2,3,6) and 27.1-27.2 notes, concept checks due

next Friday 2/22 and online Monday 2/25 Test that Wed.

A “Switch” is an enhancer

• As the video explains, although two organisms may both possess the same gene linked to a particular trait, this trait may not be expressed unless the gene is turned on. This is done by an enhancer, a piece of noncoding DNA—previously thought of as "junk" DNA—that acts as a "switch." (NOVA, What Darwin Never Knew)

Organization of a Typical Eukaryotic Gene

• Associated with most eukaryotic genes are multiple control elements, segments of noncoding DNA that serve as binding sites for transcription factors that help regulate transcription

• Control elements and the transcription factors they bind are critical to the precise regulation of gene expression in different cell types

© 2011 Pearson Education, Inc.

Figure 18.8-1

Enhancer(distal control

elements)

DNA

UpstreamPromoter

Proximalcontrol

elementsTranscription

start site

Exon Intron Exon ExonIntron

Poly-Asignal

sequenceTranscriptiontermination

region

Downstream

• Proximal control elements are located close to the promoter

• Distal control elements, groupings of which are called enhancers, may be far away from a gene or even located in an intron

Enhancers and Specific Transcription Factors

© 2011 Pearson Education, Inc.

• An activator is a protein that binds to an enhancer and stimulates transcription of a gene

• Activators have two domains, one that binds DNA and a second that activates transcription

• Bound activators facilitate a sequence of protein-protein interactions that result in transcription of a given gene

© 2011 Pearson Education, Inc.

© 2011 Pearson Education, Inc.

Animation: Initiation of Transcription

Right-click slide / select “Play”

ActivatorsDNA

EnhancerDistal controlelement

PromoterGene

TATA box

Generaltranscriptionfactors

DNA-bendingprotein

Group of mediator proteins

RNApolymerase II

RNApolymerase II

RNA synthesisTranscriptioninitiation complex

Figure 18.10-3

Figure 18.9

DNA

Activationdomain

DNA-bindingdomain

• Some transcription factors function as repressors, inhibiting expression of a particular gene by a variety of methods

• Some activators and repressors act indirectly by influencing chromatin structure to promote or silence transcription

© 2011 Pearson Education, Inc.

Figure 18.11

Controlelements

Enhancer Promoter

Albumin gene

Crystallingene

LIVER CELLNUCLEUS

Availableactivators

Albumin geneexpressed

Crystallin genenot expressed

(a) Liver cell

LENS CELLNUCLEUS

Availableactivators

Albumin genenot expressed

Crystallin geneexpressed

(b) Lens cell

Coordinately Controlled Genes in Eukaryotes

• Unlike the genes of a prokaryotic operon, each of the co-expressed eukaryotic genes has a promoter and control elements

• These genes can be scattered over different chromosomes, but each has the same combination of control elements

• Copies of the activators recognize specific control elements and promote simultaneous transcription of the genes

© 2011 Pearson Education, Inc.

Figure 18.12

Chromosometerritory

Chromosomes in theinterphase nucleus

Chromatinloop

Transcriptionfactory

10 m

Hox genes code for transcription factors that create body axis

Found in all animals,Hox genes act to "regionalize" the body along the embryo's anterior-to-posterior (head-to-tail) axis.

Hox vs. later epigenetic mechanisms

• Hox genes make the initial decisions of which genes to turn on or off in different body regions and cell types.

• Later in an animal's development, epigenetic switches take over, controlling the "on" and "off" state of genes within each cell.

• Remember some of these epigenetic mechanisms of gene expression?

Figure 18.6 Signal

NUCLEUSChromatin

Chromatin modification:DNA unpacking involvinghistone acetylation and

DNA demethylationDNA

Gene

Gene availablefor transcription

RNA ExonPrimary transcript

Transcription

Intron

RNA processing

Cap

Tail

mRNA in nucleus

Transport to cytoplasm

CYTOPLASM

mRNA in cytoplasm

TranslationDegradationof mRNA

Polypeptide

Protein processing, suchas cleavage and

chemical modification

Active proteinDegradation

of proteinTransport to cellular

destination

Cellular function (suchas enzymatic activity,structural support)

Organize the following terms into a flowchart

• Adaptation, Environmental Change, Natural Selection, Species Changes, Variation exists

Can Individuals Evolve?

List as many categories of Evidence of Evolution as you can

What are the 2 main causes of genetic variation?

• Microevolution =

• Population =

Natural Selection = only mechanism that gives consistent Adaptive Evolution

• Relative fitness?

• 3 ways that it can affect phenotype distribution – name and draw

Genetic variation preserved how?

• Why not perfection?

Speciation – when does evolution result in a new species?

• Species defined =

• Macroevolution =

• What are 2 main types of reproductive isolation?

Prezygotic vs. Postzygotic

• Describe various methods of prezygotic: isolation: habitat, behavioral, temporal, mechanical, gametic

• Describe various methods of postzygotic:

Reduced hybrid viability, Reduced hybrid fertility, Hybrid breakdown

Allopatric vs. Sympatric speciation – has to do with geographic

isolation• Allopatric:

• Sympatric:

Speed of Speciation

• Gradualism

• Punctuated Equilibrium & Adaptive radiation

5 conditions of Hardy-Weinberg Equilibrium? Is it realistic?

What is genetic drift? Give 2 examples

Match up the person with the theory

• Carolus Linnaeus

• Aristotle

• Old Testament

• Lamarck

• Cuvier

• Lyell

• Darwin

• Uniformitarianism• Use and Disuse• Natural Selection• Catastrophism• Taxonomy• Scala naturae• Binomial Nomenclature• God designed perfect

species• Inheritance of Acquired

Characteristics

Classification terms

• Phylogeny = – Inferred from homologous structures and molecular

data• Systematics =

• Taxonomy = – Binomial nomenclature– DKPCOFGS – look at table of 3 domains– Taxon

• Phlyogenetic Tree• Cladogram and clades

Molecular systematics

• DNA that codes for rRNA

• DNA that codes for mitochondrial DNA

• Molecular clocks