warrior final review

Upload: kevin-dean-lim

Post on 04-Apr-2018

214 views

Category:

Documents


0 download

TRANSCRIPT

  • 7/30/2019 Warrior Final Review

    1/100

    Cell Division

    Dewey Nguyen

  • 7/30/2019 Warrior Final Review

    2/100

    Mitosis somatic/body or boring cell

    division!

    Two identical daughter cells, just like parent

    cell

    Diploid, 2n, two copies of each chromosome

  • 7/30/2019 Warrior Final Review

    3/100

    Interphase- Prep phase for mitosis

    G1 make organelles and producemacromolecules

    SDNA is decondensed form of

    chromatin,DNA replication

    G2 additional growth

  • 7/30/2019 Warrior Final Review

    4/100

    The 5 Mitotic Phases - Prophase

    Formation of mitotic spindles

    Centrosomes are moving to opposite ends

    Sister chromatids are condensed

  • 7/30/2019 Warrior Final Review

    5/100

    Prometaphase

    Nuclear envelope is broken down

    Kinetochore microtubules are attached tocentromeres

    Non-attaching kinetochore microtubuleselongate the cell

  • 7/30/2019 Warrior Final Review

    6/100

    Question

    The ____ end of the kinetochore microtubules

    requires _______ to pull the chromosomes

    toward the plasma membrane.

    a) Positive, dynein

    b) Postive, kinesin

    c) Negative, dyneind) Negative, kinesin

    e) Actin, myosin

  • 7/30/2019 Warrior Final Review

    7/100

    The final steps

    Metaphase plate formed in metaphase

    Anaphase sister chromatids are separated

    Telophase and Cytokinesis cleavage using

    actin filaments and myosin, nuclear envelopeformation

  • 7/30/2019 Warrior Final Review

    8/100

    Question

    Sister chromatids would first be seen at this

    stage:

    a) G1

    b) S

    c) Prophase

    d) Metaphasee) B and C

  • 7/30/2019 Warrior Final Review

    9/100

    Question

    A drug is found to disrupt the function of kinesin,

    how would this drug affect mitosis?

    a) The cell cannot elongate for cell division

    b) Sister chromatids cannot be separated

    c) Cytokinesis cannot take place

    d) A and B

    e) None of the above

  • 7/30/2019 Warrior Final Review

    10/100

    Oh Meiosis - the sex cell division

    Four different daughter cells

    Haploid, n, one copy of each chromosome

    All stages are very similar to Mitosis

  • 7/30/2019 Warrior Final Review

    11/100

    Oh Meiosis

    Metaphase I homologous chromosomesformed tetrads and crossing over occurs here!

    Independent assortment- Metaphase I and II

    increases genetics variation

  • 7/30/2019 Warrior Final Review

    12/100

    Sister homologous what!?!?

  • 7/30/2019 Warrior Final Review

    13/100

    Oh I get it!

    Sister chromatids are the exact same thing!

    Homologous chromosomes carried thedifferent variations of the same gene!

    Non-homologous chromosomes are differentchromosomes!

  • 7/30/2019 Warrior Final Review

    14/100

    Crossing-Over is what?!?!

    Yes, crossing-over is chromosomal sex, where

    genetic materials are exchanged! So sister

    chromatids cannot do it together! Only do it

    with the same chromosome or homologouschromosome!

    Must hold hand first, so tetrad are formed,

    and then Chiasmata! Lets take a closerlook!

  • 7/30/2019 Warrior Final Review

    15/100

    So this is how they do it!

  • 7/30/2019 Warrior Final Review

    16/100

    Mendel

    Law of segregation

    Two alleles will separate

    into two different

    gametes

    Law of independent

    assortment

    When two or more

    characters are inherited,each alleles separated into

    gametes independently

    Wait what is the point of these two law?

    - To create more variations!

  • 7/30/2019 Warrior Final Review

    17/100

    Test Cross

    To test if a phenotype is homozygous

    dominant or heterozygous dominant.

    Cross with a homozygous recessive

  • 7/30/2019 Warrior Final Review

    18/100

    Non-Mendelian Inheritances

    Incomplete dominance Co-dominance

    Multiple Alleles

    Pleiotropy

    Epistasis

    Polygenic inheritance Environmental factors/impacts

  • 7/30/2019 Warrior Final Review

    19/100

    Non-Mendelian Inheritances

    Lets say R = red, and r = white. So Rr would

    yield:

    Incomplete dominance

    Co-dominance

  • 7/30/2019 Warrior Final Review

    20/100

    Recombination

    Map units dont add up!

    Offspring show different phenotype fromparents!

  • 7/30/2019 Warrior Final Review

    21/100

    Abnormalities

    Karyotopic Abnormalities having an

    abnormal number of chromosomes

    Chromosomal aberrations a part of a

    chromosome is messed up!

    Only translocation can involve two chromosomes

  • 7/30/2019 Warrior Final Review

    22/100

    Question

    Your father is color blind, and your sister isalso color blind, but you are not. What is theprobability that you will have a diseased

    brother?a) 0

    b) 1/2

    c) 1/4

    d) 1/8

    e) None of the above

  • 7/30/2019 Warrior Final Review

    23/100

    Question

    Your father has achondroplasia, and yoursister also has achondroplasia, but you arenot. What is the probability that you will have

    a diseased brother?a) 0

    b) 1/2

    c) 1/4

    d) 1/8

    e) None of the above

  • 7/30/2019 Warrior Final Review

    24/100

    Question

    A female duck has a mosaic feathers, what

    could be one explanation for this?

    a) Barr body

    b) Incomplete dominance

    c) Co-dominance

    d) Epistasise) More than one possible answer

  • 7/30/2019 Warrior Final Review

    25/100

    Bio Sci Peer TutoringFINAL Review: Bio93 Sec A+B

    Arun Manmadhan

    UNIT VI: Molecular Biology

  • 7/30/2019 Warrior Final Review

    26/100

    Frederick Griffith

  • 7/30/2019 Warrior Final Review

    27/100

    So what did this show/mean??

    S (Smooth) cell = DEADLY smooth slimy coat gives the bacteria protection

    R (Rough) cell = Harmless

    Heat killed S cell = Harmless The cell is killed but not the DNA

    Heat killed S cell + R cell = DEADLY

    DNA from heat killed S cell transforms the R cell

    into an S cell KEY POINT: Showed that there exists a

    transforming principle but not necessarilyDNA, RNA or Protein

  • 7/30/2019 Warrior Final Review

    28/100

    Showed that DNA was the transforming agent

    and thus the unit of hereditary.

    Phage = a virus

    SULFUR is FOUND in Protein but NOT inDNA

    Phosphorous is FOUND in DNAbut NOT inProtein

    Alfred Hershey and Martha Chase

    Experiment

  • 7/30/2019 Warrior Final Review

    29/100

  • 7/30/2019 Warrior Final Review

    30/100

  • 7/30/2019 Warrior Final Review

    31/100

    Rosalind Franklin, Watson & Crick

    Rosalind Franklin used X-ray crystallography toget a real picture of DNA

    Watson and Crick then analyzed the picture to

    come up with a structure that FIT the data Basic Postulates:

    1. DNA is LINEAR

    2. DNA base pairing rules

    A=T, C G

    3. HELICAL structure

  • 7/30/2019 Warrior Final Review

    32/100

    Properties of DNA

    Purines = Guanine (G) and Adenine (A)

    Pyrimadines = Thymine (T) and Cytosine (C)

    Phophate group = 5 end

    Sugar group = 3 end DNA is anti-parallel one strand = 53

    the other = 35

    DNA replication is SEMI-CONSERVATIVE

    DNA is replicated with DNA POLYMERASE

  • 7/30/2019 Warrior Final Review

    33/100

    One parental isPreserved, the second strand

    (red) is new

    Semiconservativemodel:Type of DNA

    replication in which thereplicated double helixconsists ofone oldstrand, derived fromthe old molecule, andone newly made strand

    Definition G-33

  • 7/30/2019 Warrior Final Review

    34/100

    Question

    In the Hershey and Chase experiment with thebacteriophages, the most important clue tothe chemical nature of the hereditarymaterial was the:

    a)incorporation of radioactive sulfur in the bacterialgenome

    b)incorporation of radioactive phosphorus in the bacterialgenome

    c)transformation of R cells to S cells via heat killed S cells

    d) accumulation of phosphorus on the surface of thebacteria

  • 7/30/2019 Warrior Final Review

    35/100

    Question

    If one strand of a DNA molecule has the basesequence 5-ATTGCAT-3, its complementarystrand will have the sequence:

    A) 5-ATTGCAT-3

    B) 5-ATGCAAT-3

    C) 5-TAACGTA-3D) 5-CGGTACG-3

    E) None of the above

  • 7/30/2019 Warrior Final Review

    36/100

    Solution Sequence given:

    5-ATTGCAT-3

    3-TAACGTA-5

    5-ATGCAAT-3

    This is the complementary strandBut since all options are written53 flip it!

    Same as choice B

  • 7/30/2019 Warrior Final Review

    37/100

    The Central Dogma

    DNA DNA

    RNA=Transcription

    mRNA 5 cap Poly A Tail RNA Splicing

    Protein RNA

    Protein =translation

    Lecture 22

  • 7/30/2019 Warrior Final Review

    38/100

    Prokaryotes vs Eukaryotes

    Prokaryotes Eukaryotes

    MORECOMPEX!

  • 7/30/2019 Warrior Final Review

    39/100

    Transcription

    Initiation: Promoterregion + transcriptionfactors

    Promoter region =DNA sequences whichprovide a binding sitefor RNA polymerase

    TranscriptionFactors= recruit RNApol to the promoterregion

  • 7/30/2019 Warrior Final Review

    40/100

    Transcription continued

    Elongation = RNApolymerase adds RNAnucleotides until it hits atermination spot

    Termination = RNApolymerase disassociatesfrom the template DNA

    strand and primary transcriptis released to be processed.

  • 7/30/2019 Warrior Final Review

    41/100

    QuestionIn order for a particular drug to directly inhibit

    RNA polymerase activity in animals it must

    have:A) Non-polar functional groups

    B) Nuclear import signal

    C) Compatible transcription factorsD) Complementary sequences to the promoter

    E) None of the above

  • 7/30/2019 Warrior Final Review

    42/100

    QuestionPromoters for eukaryotic mRNA synthesis:

    A) are more complex than prokaryotic promoters

    B) can require binding of multiple transcriptionfactors to form a transcription complex

    C) have specific DNA sequences such as the"TATA" box that are recognized by proteins

    D) are the stretches of DNA to which RNApolymerase binds to initiate transcription

    E) All of the above

  • 7/30/2019 Warrior Final Review

    43/100

    Everythingoccurs

    in thecytoplasm

    Transcription

    + RNAprocessing intheNUCLEUS

    Translationin

    CYTOPLASM

    Bacteria!

    YOU &ME!!

  • 7/30/2019 Warrior Final Review

    44/100

    RNA processing 5 cap added - Capping ensures the messenger

    RNA's stability while it undergoes translation

    Mostly Guanine (G) repeats

    Poly A Tail - important for the nuclear export,translation and stability of mRNA. The tail isshortened over time and when it is short enough,the mRNA is enzymatically degraded.

    Adenosine (A) repeats

  • 7/30/2019 Warrior Final Review

    45/100

    RNA splicing

    exon intron Exon Intron Exon Intron

    Exon Exon Exon

    Introns REMOVED

    INTrons = INTerfere

    5 cap Poly ATail

    Primary Transcript

    Mature Transcript

    + 5cap + poly A Tail

  • 7/30/2019 Warrior Final Review

    46/100

    Genetic Code

    Memorize!!!: Start Codon: AUG Stop Codons: UAA, UGA, UAG

    The genetic code is read in triplets (codons)

    It is non-overlapping The genetic code is unambiguous

    Each codon specifies a particular amino acid, andonly one amino acid.

    The genetic code is degenerate. each amino acid can be specified by more than one

    codon.

    The code is nearlyuniversal.

  • 7/30/2019 Warrior Final Review

    47/100

  • 7/30/2019 Warrior Final Review

    48/100

    QuestionWhich of the following is NOT a feature of eukaryotic

    gene expression?

    A) Random repeat segments at mRNA polesB) many genes are interrupted by non-gene coding

    DNA sequences

    C) RNA synthesis and protein synthesis are coupled

    D) mRNA is often extensively modified beforetranslation

    E) Addition of a nuclear export tag to mature mRNA

  • 7/30/2019 Warrior Final Review

    49/100

    Translation important points tRNA molcules are the translators

    Purpose??? MAKE PROTEIN, PROTEIN, ANDMORE PROTEIN!!!!!

    PossesANTI-CODONS to the CODONS found in

    mRNA Thus if mRNA has codon: 5-AUG-3, tRNA has

    the complementary anti-codon: 3-UAC-5

    Ribosomes read mRNA in 53 direction

    E site: Exit site, tRNAs leave P site: Peptidyl site, amino acid chain lives/

    grows here

    A site: Acceptor, temporary home for tRNAs

  • 7/30/2019 Warrior Final Review

    50/100

    What does that spell?! E-P-A

    Environmental ProtectionAgency

  • 7/30/2019 Warrior Final Review

    51/100

    Mutations Oh Nooooo! Base pair substitution

    Types: Silent: mutation has no effect on amino acid

    added b/c genetic code is DEGENERATE

    Missense: mutation changes one amino acidbecause of mutation

    Nonsense: mutation results in a STOP codon,prematurely cuts the amino acid chain

    Normal Wildtype Mutant

    5-AUGAAGUUUGGCUAA-3 5-AUGAAGUUUGGUUAA-3

  • 7/30/2019 Warrior Final Review

    52/100

    Mutations continued

    If mutations add or remove nucleotides inanything BUT multiples of three, the mutation isa FRAMESHIFT

    Wildtype:

    THE|FAT|CAT|ATE|THE|WEE|RAT

    Mutant (frameshift mutation): THE|FAT|CAT|ATE|THZ|ZWE|ERA|T

    Insert ONE or TWO Nucleotides

  • 7/30/2019 Warrior Final Review

    53/100

    QuestionA nonsense mutation generally results in:

    A) Translation of incorrect amino acids

    B) a shorter polypeptide

    C) no change in expressed protein

    D) a frameshift

  • 7/30/2019 Warrior Final Review

    54/100

    QuestionWhich of the following is NOT correct?

    A) There are sixty-four different codons.

    B) All codons specify a specific amino acid.

    C) Some codons are used for initiation or

    terminationD) There are more codons than amino acids

    E) All of the above are correct

  • 7/30/2019 Warrior Final Review

    55/100

    DNA Cloning In Bacteria

    First Step: IsolateDNA/Gene of interest

    Second Step: Insert

    DNA into a PLASMID

    Third Step: AllowBacteria to incorporateDNA and multiply

    Fourth Step: Observe/Extract protein of interestsynthesized

  • 7/30/2019 Warrior Final Review

    56/100

    Cutting DNA

    You need palindrome sequences IE racecar Read from both directions = same word

    Restriction enzymes cut DNA at thesepalindrome sequences

    Create Sticky Ends Once DNA has been inserted into a plasmid,

    covalent bonds are reformed using DNA Ligase

  • 7/30/2019 Warrior Final Review

    57/100

    PCR Reaction Start with one piece of

    DNA

    Can amplify and duplicatemillions and billions ofcopies in a few hours.

  • 7/30/2019 Warrior Final Review

    58/100

    Gel electrophoresis

    Purpose: Separate DNA sequencesBased on size.

    Allows for identification of certainSequences of DNA.

    DNA is negatively charged, so movesTo positive end. Smaller DNAMolecules feel less resistance in the

    Gel and thus move a greater distance.

    What makes DNANEGATIVELYCharged????

  • 7/30/2019 Warrior Final Review

    59/100

    Continued (Copied from your lecture

    notes) KNOW THIS!

    1. A SMALL fraction of the genes in the genomeare expressed in any given cell

    2. Gene expression can also be regulated at manyother steps such as

    1. RNAprocessing,

    2. RNAtransport,

    3. RNAstability/degradation,4. RNAtranslation,

    5. Proteinmodification

    6. Proteinstability/degradation.

  • 7/30/2019 Warrior Final Review

    60/100

    Continued

    Transcription Factors: Tell the cell/polymerasesWHEN andWHERE transcriptioncan occur

    Enhancers: Work with transcription factors andthe promoter region to stimulate transcription.

    Micro RNA (miRNA) attach to MATUREmRNA and either DEGRADE or PREVENTTRANSLATION

  • 7/30/2019 Warrior Final Review

    61/100

    Gene Expression

    So MANYcheck points that can control how the gene is expressed

  • 7/30/2019 Warrior Final Review

    62/100

    Question

    Which of the following tools of recombinant DNAtechnology is INCORRECTLY paired with one of itsuses?

    A) restriction enzyme - production of DNA fragmentsfor gene cloning

    B) DNA ligase - enzyme that cuts DNA, creating stickyends.

    C) DNA polymerase - copies DNA sequences in thepolymerase chain reactionD) Electrophoresis - Detect DNA lengthE) Antibiotic resistance - detect if bacteria

    transformed

  • 7/30/2019 Warrior Final Review

    63/100

    Question

    Which of the following is not part of the normalprocess of cloning recombinant DNA in bacteria?

    A) restriction enzyme digestion of cellular andplasmid DNAs

    B) production of recombinant DNA using DNA ligasesand a mixture of digested cellular and plasmidDNAs

    C) separation of recombinant DNAs by

    electrophoresisD) transformation of bacteria by the recombinant

    DNA plasmidsE) All of the above are valid processes

  • 7/30/2019 Warrior Final Review

    64/100

    Time permitting questions

    The regions of DNA in a eukaryotic gene thatencode a polypeptide product are called:

    A) promoters

    B) Exons

    C) Introns

    D) tRNA's

    E) Transcription factors

  • 7/30/2019 Warrior Final Review

    65/100

    Question

    Three types of RNA involved in comprising thestructural and functional core for proteinsynthesis, serving as a template for translating,and transporting amino acid, respectively are:

    A)mRNA,tRNA,rRNA

    B)rRNA,tRNA,mRNA

    C)tRNA,mRNA,rRNAD)tRNA,rRNA,mRNA

    E)rRNA,mRNA,tRNA

  • 7/30/2019 Warrior Final Review

    66/100

    Question

    A messenger acid is 336 nucleotides long,including the initiator and termination codons.The number of amino acids in the proteintranslated from this mRNA is:

    A) 999B) 630C) 330D) 111E) 112

  • 7/30/2019 Warrior Final Review

    67/100

    Question

    A key feature for the identification of plasmidscontaining recombinant DNA is *hint white vsblue colonies):

    A) weighing it

    B) the DNA sequencing of recombinant plasmids

    C) the production of restriction maps ofrecombinant plasmids

    D) introns can be moved to new locations withinthe gene

    E) the disruption of a gene on the plasmid by theinserted recombinant DNA

    Recommended Animations To Watch

  • 7/30/2019 Warrior Final Review

    68/100

    Recommended Animations To Watch

    (copy and paste into browser each link

    separately) http://nortonbooks.com/college/biology/animations/ch12a01.htm

    http://highered.mcgraw-hill.com/olc/dl/120076/bio21.swf

    http://www.sumanasinc.com/webcontent/animations/content/meselson.html

    http://bcs.whfreeman.com/thelifewire/content/chp12/1202001.html

    http://www-class.unl.edu/biochem/gp2/m_biology/animation/gene/gene_a3.html

    http://bcs.whfreeman.com/thelifewire/content/chp14/1402001.html

    http://highered.mcgraw-hill.com/sites/0072556781/student_view0/chapter11/animation_quiz_4.html

    http://highered.mcgraw-hill.com/sites/0072556781/student_view0/chapter14/animation_quiz_1.html

  • 7/30/2019 Warrior Final Review

    69/100

    Developmental Biology

    Kevin Huang

    M, F 2-3 PMSH 149

    [email protected]

    D l t l Th

    mailto:[email protected]:[email protected]:[email protected]
  • 7/30/2019 Warrior Final Review

    70/100

    Developmental TheoryA combination of Cytoplasmic Determinants and Cell Induction

    Cytoplasmic Determinants:are present in egg(maternalinheritance) before fertilization.When zygote divides, differentdeterminants yield different celllineages.

    My interpretation of CD's: essentially establishthemselves during early divisions of cleavage(You likely don't have to know that bicoid is anexample of C.D.'s but it doesn't hurt for me totell you)

    Cell induction: the result of

    intercellular communication.Signals from one cell influencethe fate of another cell.

    My interpretation of C.I.: Common examples thatyou guys see cell induction could extend tothe actions of organizers which secrete

    signals (morphogens) to influencedifferentiation!

    Pattern formation vs Positional

  • 7/30/2019 Warrior Final Review

    71/100

    Pattern formation vs. PositionalInformation

    Pattern formation: theestablishment of axes A/P, D/V, P/D(determined by maternalcytoplasmic determinantspresentin the egg before fertilization).Howdoes this make sense? Well, you

    know bicoid is a C.D. anddetermines A/P polarity!

    Positional Information: directspattern formation by givingpositional values to cells.

    Dumbing it down: positionalinformation --> This definition likelydoesn't make senseso think of itin terms of how morphogens work.Morphogens (like bicoid) yield aconcentration gradient. Differentlevels of bicoid yield different celltypes. HENCE, DIFFERENT

  • 7/30/2019 Warrior Final Review

    72/100

    Drosophilaand bicoid

    In drosophila, cytoplasmicdeterminants are present in theegg before fertilization.Fertilization results activation ofthe egg.

    The resulting activation initiatesa bicoid gradient across theembryo (highest at anterior,lowest at posterior)

    High [bicoid] = head

    Intermediate [bicoid] = thorax

    Bicoid acts as a morphogen

  • 7/30/2019 Warrior Final Review

    73/100

    Embryonic Development - Overview

    Fertilization

    Cleavage

    Gastrulation

    Organogenesis

    Fusion of haploid egg/sperm toform a diploidzygote (influx ofCa2+ results in eggactivation)

    Rapid cell divisions without anincrease in overall size. Thuswith each successive cleavagedivision, each cell becomessmaller.

    Cell movement, forms germlayers (ectoderm, mesoderm,endoderm)

    formation of organs (formationof neural tube to become future

    spinal cord/brain)

    Fertilization

  • 7/30/2019 Warrior Final Review

    74/100

    e t at ohaploid sperm + haploid egg = diploid zygote

    - Entry of sperm results in an influxof Ca2+ into the egg.

    - This results in increased proteinsynthesis, etc.

    - Egg is activatedat this point.

    Acrosomal rxn: there are specificreceptors for the sperm. Thisessentially prevents interspeciesfertilization

    Cortical rxn: essentially prevents

    polyspermy by blocking the entry ofadditional sperm.

    (acrosomal rxn occurs before corticalrxn)

    Cl

  • 7/30/2019 Warrior Final Review

    75/100

    CleavageThe initial divisions of the embryo

    - Rapid cell divisions that proceedafter fertilization. Involvesduplication of organelles and DNAbut no overall growth!!!

    - Form of mitosis (once again: NOGROWTH)

    - Morula is formed during cleavage.At the end of cleavage a blastula iscreated.

    - the blastula has a cavity within itcalled the blastocoel

    G t l ti

  • 7/30/2019 Warrior Final Review

    76/100

    GastrulationFormation of germ layers

    - Dorsal lipinvaginatesinto theinterior of the embryo in a processcalled involution.

    - The blastocoel shrinks and in itsplace another cavity called thearchenteron is present

    - Blastopore lip encircles the yolk plug

    - Generates the 3 germ layers:

    - Ectoderm (outer)

    - Mesoderm (middle)

    - Endoderm (inner)

    Because not a lot of background information isgiven to you guysRemember that theblastocoel is characteristic of the blastula,and the archenteron is characteristic ofgastrulation.

    Know the 3 germ layer fates

  • 7/30/2019 Warrior Final Review

    77/100

    Know the 3 germ layer fates(general, not super specific!)

    Ectoderm

    Mesoderm

    Endoderm

    epithelial/outer covering like the skin (easy toremember)

    Central nervous system (brain, spinal cord)How to remember this: You know that theneural plate is ectoderm, and receives signalsfrom the notochord to become FUTUREspinal cord/brain!!

    Notochord (you know that the notochord ismesoderm and signals to the overlyingectodermneural plate)

    Muscular, skeletal, circulatory

    Gastrointestinal tract (looking at diagram onprevious slide, you see that endoderm is theprimary cell tissue type within the gastrula! Itessentially invaginates to become the gut)

    Organogenesis

  • 7/30/2019 Warrior Final Review

    78/100

    Organogenesiscreation of organs

    Germ layers (ectoderm, mesoderm,endoderm) develop into rudiments oforgans

    Vertebrate organogenesis: neuralplate (ectoderm), notochord(mesoderm)

    Mesoderm surroundingnotochord somites (whichsplit to become body cavity)

    Neural

    fold

    Neural plate

    Neural crest

    Outer layer

    of ectodermNeural crest

    Neural tube

    CNS Formation (Brain/Spinal Cord)

  • 7/30/2019 Warrior Final Review

    79/100

    CNS Formation (Brain/Spinal Cord)Organogenesis

    Notochord (mesoderm)signals to overlying neuralplate (ectoderm) whichresults in the inward folding ofthe plate---forming the neuraltube (future brain/spinalcord)

    Requires microtubules, actin

    Somites

  • 7/30/2019 Warrior Final Review

    80/100

    SomitesKey to early embryonic segmentation

    Not a lot is told to you guysabout somites

    What I think you should know:

    Somites = mesoderm

    surrounding notochord Shows segmentation

    Somites

    HEAD

    Neuraltube

    Neural folds

    Head mesoderm

    Tail

    Organizers

  • 7/30/2019 Warrior Final Review

    81/100

    OrganizersImportant stuff!

    Organizers act sort of likecommand centers. Whereverthey are present, they enforcetheir demands

    What do I mean by this?

    They secrete factors (morphogens) thataffect gene expression insurrounding cells

    If you graft organizers of particularregions into foreign regions, theorganizer will cause surroundingcells to change their destiny

    Ex: you graft a foot organizerwhere hands normally form---youwill get feet for hands!

    Organizers to know:

    1) dorsal lip ofblastopore

    notochord/neural tubeformation

    2) apical ectodermalridge (AER)

    Limb bud pattern formation

    3) Zone ofPolarizing Activity(ZPA)

    - limb bud pattern formation

    AER/ZPA

  • 7/30/2019 Warrior Final Review

    82/100

    AER/ZPA

    ZPA secretes Sonichedgehog which givespositional informationposterior to anterior.

    AER is overlying ectoderm

    ENGRAFTMENT OF NEWZPA YIELDS POSTERIORIDENTITY AT NEWLOCATION (notice in pic.That there are two pinkies,and two ring fingers :O)

    Homeotic Genes vs Organizers

  • 7/30/2019 Warrior Final Review

    83/100

    Homeotic Genes vs. Organizersanatomic identity

    What to know: HOMEOTIC GENES: Code

    foranatomic identity (ex:tells a particular segmentyou are going to be a

    hand) ORGANIZERS: secrete

    signals that influence geneexpression in surroundingcells

    Homeotic is at the GENElevel

    Organizers at the CELLULARlevel

    Tidbits you might want to be aware

  • 7/30/2019 Warrior Final Review

    84/100

    Tidbits you might want to be awareof....

    Zygote (result of fertilization)

    Morula (during cleavage divisions)

    Blastula (the result of cleavage divisions)

    Gastrula (result of gastrulation)

    Neurula (result of neuralation)----this is known in our lectures as our exampleof ORGANOGENESIS....therefore know that the neural tube folding is duringorganogenesis!

    Blastomeresare the individual cells that make up the morula and blastula

    during cleavage...

    Discussion Generation:

  • 7/30/2019 Warrior Final Review

    85/100

    The questions I present here are intended to broaden yourunderstanding and help see the bigger picture if development and how

    they may apply to other topics in the class :)

    Do organizers function as cytoplasmic determinants or cellinduction? What kind of signals to they secrete?

    harder question: How do organizers affect homeotic geneexpression? Be as specific as possible!

    Another harder question: How do organizers change theexpression of cells in the area in which an engraftment hasoccured?

    Although the acrosomal rxn functions to prevent interspecies fertilization,sometimes it does not work indefinitely.

  • 7/30/2019 Warrior Final Review

    86/100

    Ex: the zorse (buahaha. . .)real example: a mule (horse + donkey)

    A mule is formed by the mating of a horse and a donkey. Thismeans in this situation acrosomal rxn function failed, howeverthe species were compatible enough that an embryo wasviable enough to develop. If I told you the # of chromosomes ina horse was 64, and in a donkey 62, and in a mule 63---why do

    you think mule are sterile (cannot mate)? Random and irrelevant fact:when I looked up these values it turned out to be these exact numbers...creepy.

    Hint: this does not relate towards development, think cell cycle.

    What could be the best way to define the sort of signaling that

  • 7/30/2019 Warrior Final Review

    87/100

    What could be the best way to define the sort of signaling thatcytoplasmic determinants and morphogens convene?

    What if you could inhibit all mesoderm signaling to the ectoderm? Based

  • 7/30/2019 Warrior Final Review

    88/100

    off of what you know, what kind of long term effects can this have on theorganism?

  • 7/30/2019 Warrior Final Review

    89/100

    THE NERVOUS SYSTEM

    Wendys fun-filled introduction toNeurons

    Brains are cool! Girls love brains.

    L b l th N

  • 7/30/2019 Warrior Final Review

    90/100

    Label the Neuron

    Indicate where the concentration of the

    following ions are highest in the neuron:

    Na+, K+, Cl-, and anions-

    L b l th A ti P t ti l

  • 7/30/2019 Warrior Final Review

    91/100

    Label the Action Potential

    A:

    B:

    1:

    2:

    3:

    4:

  • 7/30/2019 Warrior Final Review

    92/100

    Will the ion move in or out of the cell using thesechannels:

    1. Voltage-gated Na+ Channels ___________

    2. Voltage-gated K+ Channels ____________

    3. Non-gated K+ Channels ______________

    Label the Synapse

  • 7/30/2019 Warrior Final Review

    93/100

    Label the Synapse

    A:

    B:

    C:

    D:

    E:

    F:

    G:

    H:

  • 7/30/2019 Warrior Final Review

    94/100

    What part of the neuron relays signals from

    one neuron to another neuron?

    a. Dendrite

    b. Axon hillockc. Synaptic Terminal

    d. Axon

    e. Node of Ranvier

  • 7/30/2019 Warrior Final Review

    95/100

    The part of the neuron that carries an impulsetowards the cell body is called ________.

    a. A nerve

    b. A neurotransmitter

    c. An axon

    d. A dendrite

    e. White matter

  • 7/30/2019 Warrior Final Review

    96/100

    The membrane potential refers to:

    a. The voltage inside a cell during an action potential.

    b. The difference in voltage between the inside of the

    cell and the outside of a cell

    c. Ion gradients in excitable cells

    d. Graded changes in polarization

    e. The fact that neuronal cells must generate more

    membrane when they grow

  • 7/30/2019 Warrior Final Review

    97/100

    An EPSP (excitatory postsynaptic potential)

    facilitates depolarization of the postsynapticmembrane by:

    a. increasing the permeability of the membrane toNa+

    b. increasing the permeability of the membrane toK+

    c. insulating the hillock region of the axon

    d. allowing Cl to enter the celle. stimulating the sodium-potassium pump

  • 7/30/2019 Warrior Final Review

    98/100

    For each statement, determine if the neuron

    membrane will be hyperpolarized, depolarizedor no change.

    Binding of serotonin to ligand gated K+ channels__________________

    After summation of inhibitory postsynaptic

    potentials _______________

  • 7/30/2019 Warrior Final Review

    99/100

    What is the approximate threshold? _________

    Which letter(s) represent inhibitory post-synaptic potential? ________Which letter(s) represent hyperpolarization? _______

    The cell is depolarizing at letter: _________

    Letter A is an example of? _________

    Good Luck on All Your Finals!

  • 7/30/2019 Warrior Final Review

    100/100

    Good Luck on All Your Finals!

    Please fill out an evaluation for us!

    Thank you!