Tommy Wiaduck 2015

Tommy Wiaduck Honors Biology Final Exam Review 2015 This study guide is an extensive collaboration of class powerpoints and independent notes. It provides a large amount of direct information. Application and use of the information ultimately depends on each individual student. It is recommended to use other resources in addition to this review. This study guide does not guarantee any scores or accuracy. If you have questions or need help in Biology, please contact Tommy Wiaduck.

TOPIC 8: THE CELLULAR BASIS OF REPRODUCTION AND INHERITANCE Connections Between Cell Division and Reproduction

Like begets like asexual reproduction

creation of genetically identical offspring by a single parent sexual reproduction

like does not beget like unique combination of traits ; variation among offspring

still similar to parents Cells arise only from preexisting cells

“Every cell from a cell” (Virchow) cell division

the reproduction of a cell Roles of cell division

asexual reproduction entirely reproduce unicellular organism grow a multicellular organism

sexual reproduction sperm and egg formation

general from fertilized egg into adult repair and renew cells

Prokaryotes reproduce by binary fission binary fission

“dividing in half” in prokaryotic cells two identical cells come from one cell

Steps: 1) Chromosome duplicates ; copies move to

opposite ends of cell wall 2) Duplication progresses ; cell elongates 3) Duplicated ; membrane grows inward dividing into 2 daughter cells

The Eukaryotic Cell Cycle and Mitosis

The large, complex chromosomes of eukaryotes duplicate with each cell division made from chromatin

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combination of DNA and protein preparation for division

chromatin coils up into compact/distinct chromosomes dividing

chromosome DNA is copied two copies of sister chromatids (identical

copies of DNA) joined at the centromere (waist)

The cell cycle multiplies cells cell cycle

ordered sequence of events for cell division Stage 1: Interphase (duplication)

G1: growth S: duplication of chromosome G2: growth, prep for division

Stage 2: Mitotic phase (division) Mitosis: division of nucleus Cytokinesis: division of cytoplasm

Continuum of dynamic changes Prophase Prometaphase Metaphase Anaphase Telophase

mitotic spindle structure formed of microtubules and proteins involved in the movements

of chromosomes during mitosis and meiosis. emerges from two centrosomes

clouds of cytoplasmic material that contain centrioles Interphase

in cytoplasm cytoplasmic contents double ; two centrosomes form

in nucleus chromosomes duplicate (S phase) nucleoli become visible

Prophase in cytoplasm:

microtubules begin to emerge forming spindle in nucleus:

chromosome coil and compact nucleoli disappear

Prometaphase spindle microtubules reach chromosomes

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move them to center of cell with protein motors nuclear envelope disappears

Metaphase spindle is completely formed chromosomes align at cell equator

Anaphase sister chromatids separate at centromeres daughter chromosomes are moved to opposite poles of the cell cell elongates

Telophase cell keeps elongating nuclear envelope forms around chromosomes

chromatin uncoils; nucleoli reappear spindle disappears

Cytokinesis differs for plant and animal cells cytokinesis

divided into two separate cells cleavage furrow (animal cells)

deepens to pinch and separate into 2 cells cell plate (plant cells)

cell plate grows outward and fuses with plasma membrane

results into two daughter cells Anchorage, cell density, and growth factors affecting cell

division growth factor

A protein that stimulates other cells to divide density­dependent inhibition

crowded cells stop dividing [when they touch one another] if cells are removed, it continues dividing to fill vacancy

anchorage dependence The requirement that to divide, a cell must be attached to a solid surface.

Growth factors signal the cell cycle control system cell cycle control system

a set of molecules (including growth factors) that triggers and coordinates events of the cell cycle

checkpoints critical points where stop and go signals regulate the cycle

G1: entry into S phase or cause cell to leave cycle (G0)(nondivinding)

G2 and M checkpoints

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Tumors cancer cells

escape controls of cell cycle, divide rapidly in absence of growth factors tumors form (abnormal masses of cells)

benign: remain at original site (safer) malignant: spread (unsafe) (cancerous)

metastasis spread of cancer cells via circulatory system

classification carcinomas

originate in coverings of body (skin, lining of intestinal tract) internal and external

sarcomas arise in supportive and connective tissue

bone, cartilage, muscle leukemias and lymphomas

blood­forming tissues (bone marrow, spleen, lymph nodes) Mitosis provides for

growth cell replacement asexual reproduction

Meiosis and Crossing Over

Chromosomes are matches in homologous pairs somatic cell

typical body (except sperm/egg) cell with 46 chromosomes one member of each pair (of 23) from each parent

homologous chromosomes matched by:

length, centromere position, locus (gene locations) sex chromosomes

X and Y (determine gender) autosomes

22 pairs of chromosomes not involved in determining gender one chromosome from each parent

Gametes have a single set of chromosomes diploid cell (2n)

contains two homologous sets of chromosomes gametes

egg and sperm cells (sec cells) haploid cells

one set of chromosomes

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fertilization haploid sperm fuses with haploid egg

forms a zygote (diploid) Meiosis reduces the chromosome number from diploid to haploid

Meiosis I Prophase I

chromosomes coil and compact homologous pairs come together by synapsis

each pair is a tetrad nonsister chromatids exchange genetic material by crossing over

Metaphase I tetrads align at the cell equator

Anaphase I homologous pairs separate and move to opposite poles

Telophase I duplicated chromosomes reach poles

nuclear envelope forms around them nucleus has the haploid number of chromosomes (n)

Meiosis II follows meiosis I w/out chromosome duplication

Prophase II chromosomes coil and compact

Metaphase II duplicated chromosomes align at cell equator

Anaphase II sister chromatids separate and chromosomes move toward

opposite poles Telophase II

chromosomes at opposite poles

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nuclear envelope forms around them cytokinesis allows four haploid cells to be produced

Mitosis and Meiosis Compared Mitosis:

growth, tissue repair, asexual reproduction, identical daughter cells 2 identical cells, same chromosome number

Meiosis: sexual reproduction, haploid daughter cells two chromosome divisions, pairing homologous chromosomes, crossing

over four different cells, ½ chromosome number

Similarities: one chromosome duplication

Crossing over further increases genetic variability crossing over

exchange of corresponding segments between two homologous chromosomes

chiasma place where two homologous chromatids attach to each other

genetic recombination allele combinations different from original chromosomes

Alterations of Chromosome Number and Structure

Karyotype is a photographic inventory of an individual’s chromosomes karyotype

display of micrographs of the metaphase chromosomes of a cell arranged by size and centromere position

pairs, number, structure of chromosomes Extra copy of chromosome 21

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trisomy 21 Down syndrome ; 47 chromosomes total

facial features, susceptible to disease shortened life span varying mental retardation

risk increases with age of mother Accidents during meiosis can alter chromosome number

nondisjunction pair of homologous chromosomes or sister chromatids fail to separate at

anaphase Meiosis I: both pair members go to one pole Meiosis II: both chromatids go to one pole

Abnormal numbers of sex chromosomes don’t usually affect survival

Alterations of chromosome structure can cause birth defects and cancers deletion

loss of a chromosome fragment duplication

repetition of a chromosome fragment inversion

reversal of chromosome segment translocation

attachment of a segment to nonhomologous chromosome TOPIC 9: PATTERNS OF INHERITANCE Mendel’s Laws

The science of genetics has ancient roots Pangenesis

pangene particles travel from every part of an organism to the sperm or eggs

acquired characteristics can be passed on (false) Blending hypothesis

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hereditary materials from both parents mix like pain

Experimental Genetics began in an Abbey Garden Gregor Mendel

showed that parents pass heritable factors (genes) to offspring pea plants

short generation times, distinguishable varieties controlled self­fertilization and cross­fertilization

self: same organism cross: two different individuals

true breeding offspring identical to parents

Mendel’s Law of segregation describes the inheritance of a single character

Generations P Generation (parental) F1 Generation

offspring of two parental individuals F2 Generation

offspring of F1 generation Cross

monohybrid cross mating of individuals that differ in one gene

P: purple x white F1: all purple F2: 3 purple ; 1 white

Four Hypothesis 1) There are alternative versions of genes (alleles) that

account for variations in inherited characters. the alternative versions of genes are called alleles

2) For each character, an organism inherits two alleles, one from each parent. They can be the same or different.

homozygous: identical alleles heterozygous: two different alleles

3) If two alleles of an inherited pair are different, one determines the appearance (dominant allele) and the other has no noticeable effect (recessive).

dominant: determines phenotype (R) recessive: doesn’t affect phenotype(r)

4) A sperm or egg carries only one allele for each inherited trait because allele pairs separate from each other during production of gametes.

law of segregation Punnett Square

Shown to the right

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Types

phenotype physical traits of an organism (purple flowers)

genotype genetic makeup of an organism (Gg)

Homologous chromosomes bear the alleles for each character alleles of a gene reside at the locus

homologous chromosomes: same allele on same locus

heterozygous: different allele on each homologue Law of independent assortment

dihybrid cross mating of individuals that differ with two genes

round yellow seeds x wrinkled green seeds (9:3:3:1 ratio)

law of independent assortment each pair of alleles segregates independently of the

other pairs of alleles during gamete formation Geneticists use testcrosses to determine unknown genotypes

testcross mating an individual of unknown genotype for a

certain trait with a homozygous recessive will show whether unknown has recessive

individual confirms true­breeding genotypes

B_ x bb BB: all black Bb: 1 black, 1 chocolate

pedigree shows inheritance of a trait in a family through generations

Many inherited disorders in humans are controlled by a single gene recessive disorders (MAJORITY)

cystic fibrosis 2 recessive alleles needed to have disease heterozygous = carriers probability of inheritance increases with mating between relatives

inbreeding dominant disorders

dwarfism ; Huntington’s disease one dominant allele needed to have disease lethal dominant alleles are eliminated from population

New technologies provide insight into one’s genetic legacy

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genetic testing can inform decisions about whether or not to have a child

fetal testing (karyotyping and biochemical testing) amniocentesis

14­20 weeks of pregnancy needle into uterus to extract amniotic fluid

chorionic villus sampling (CVS) fluid from placenta thru vagina speedy results 8­10 weeks of pregnancy

can cause risks maternal bleeding, miscarriage, premature birth

fetal imaging ultrasound

sound waves to produce pictures of fetus fetoscopy

needle­thin tube with viewing scope inserted into uterus carries risks

newborn screening catch it early enough to prevent certain downfalls

Variations on Mendel’s Laws

Incomplete dominance results in intermediate phenotypes complete dominance

dominant allele has same phenotypic effect incomplete dominance

neither allele is dominant intermediate phenotype in heterozygous individual

red x white = pink does not support blending hypothesis

hypercholesterolemia Hh is an in between in humans (incomplete dominance)

Many genes have more than two alleles in the population ABO blood types

3 alleles A, B, AB, O

codominance neither allele is dominant both alleles are present AB blood type

Single/Multiple Genes pleiotropy

one gene influencing many characteris

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sickle­cell disease shape of red blood cells, hemoglobin, etc..

polygenic inheritance many genes influence one trait

skin color (min. 3 genes) Environmental effects

phenotypic variations influenced by world around you skin color = exposure to sunlight hair = cut, dyed, etc..

see variations in twins The Chromosomal Basis of Inheritance

Genes on same chromosome tend to be inherited together linked genes

located near each other on same chromosome tend to be inherited together

Crossing over produces new combinations of alleles linked alleles can be separated by crossing over recombinant frequency

mixed genes red eyes & long wings x black eyes & short wings

recombinant: red eyes & short wings /vice versa Sex Chromosomes and Sex­Linked Genes

Chromosomes determine sex in many species sex chromosomes

designated X and Y in determining sex grasshoppers/roaches/insects

X­O system ⊳ O = absence of sex chromosome ⊳ Female: XX ; Male: XO

birds/butterflies/fish Z­W system (eggs)

⊳ Male: ZZ ⊳ Female: ZW

ants and bees chromosome number, not sex chromosomes

⊳ females: diploid (32) ⊳ males: haploid (16)

Sex­linked genes exhibit a unique pattern of inheritence sex­linked genes

gene located on sex chromosome genes associated with gender

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⊳ X­linked: mother to son and daughter ⊳ X­linked: father to daughter ⊳ Y­linked: father to sun

Sex­linked disorders affect mostly males males express X­linked disorders when there is only 1 recessive allele (females

need two) Hemophilia (bleeding)

⊳ royal families of Europe Colorblindness Duchenne muscular dystrophy

⊳ progressive weakening and loss of muscle tissue TOPIC 10: MOLECULAR BIOLOGY OF THE GENE The Structure of Genetic Material

Experiments show that DNA is the genetic material Frederick Griffith

discovered “transforming factor could be transferred into bacterial cell ⊳ disease­causing bacteria killed by heat

mouse experiment Hershey and Chase

mouse experiment to show DNA is genetic material refer to topic 10 slides for more info

bacteriophages viruses that infect bacteria cells

DNA and RNA are polymers of nucleotides nucleotides

monomers consisting of: ⊳ 5­carbon sugar ⊳ nitrogenous base ⊳ phosphate group

polynucleotide polymer of many nucleotides covalently bonded together

⊳ DNA and RNA sugar­phosphate backbone

chain of sugar and phosphate which DNA and RNA bases are attached to ⊳ Adenine, Guanine, Cytosine, Thymine

nitrogenous bases pyrimidines (single­ring)

⊳ Thymine, Cytosine

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purines (larger, double­ring) ⊳ Adenine, Guanine

RNA vs. DNA deoxyribonucleic acid

sugar: deoxyribose ribonucleic acid

sugar: rubise URACIL instead of thymine

DNA is a double­stranded helix double helix shape of DNA

Watson and Crick ⊳ helped by x­ray crystallography of Rosalind Franklin

double helix two polynucleotide chains joined together by bonding

⊳ twisted into a helical shape ⊳ “twisted railroad tracks”

base pairing purine must pair with pyrimidine to keep uniform diameter

⊳ A ­ T ⊳ G ­ C

DNA Replication

Replication depends on specific base pairing semiconservative model

DNA strands separate ⊳ one strand is kept/conserved to serve as pattern for base pairs ⊳ one old strand with one new strand

Replication proceeds in two directions at many sites simultaneously origins of replication

produces a bubble ⊳ goes from both directions from bubble origin

ends when products from bubbles merge replication direction

5’ (P) → 3’ (­OH) direction DNA polymerase

add nucleotides (link DNA nucleotides to growing strand) ⊳ add in the 3’

proofreads and removes incorrect pairings DNA ligase

links fragments together into one single DNA strand The Flow of Genetic Information from DNA to RNA to Protein

The DNA genotype is expressed as proteins Central Dogma

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DNA is transcribed into RNA ⊳ transfer of genetic information

RNA is translated into protein ⊳ transfer of RNA info to a protein

Genetic information written in codons is translated into amino acid sequences Constructing a protein

must convert nucleotides sequence to amino acid sequence transcription rewrites DNA code into RNA each codon consists of 3 nucleotides (= 1 protein) translation switches from nucleotide sequences to amino acid sequence

amino acids specified by codon

⊳ 64 possibilities of codons some have more than 1 codon

The genetic code is the Rosetta stone of life genetic code

set of rules giving the correspondence between codons in RNA and amino acids in proteins

⊳ 61 codons code for amino acids AUG codes for methionine, starts transcription

⊳ 3 stop codons (mark end of translation) more than one codon for some amino acids no codon codes for more than 1 amino acid nearly universal

⊳ codons are also adjacent to each other… no gaps Transcription produces genetic messages in the form of RNA

transcription two strands separate

⊳ one is used for starting pattern for RNA chain Adenine is replaced with RNA’s uracil

RNA polymerase ⊳ enzyme linking together growing chain of RNA nucleotides during

transcription uses DNA strand as template

stages of transcription Initiation: RNA polymerase attaches to the promoter, helix unwinds and

transcription starts ⊳ promoter: specific nucleotide sequence where RNA polymerase

binds and transcription begins Elongation: RNA nucleotides are added to the chain Termination: RNA polymerase reaches a terminator sequence and the

polymerase detaches

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⊳ terminator: DNA nucleotide sequence marking end of a gene Eukaryotic RNA is processed before leaving nucleus

messenger RNA (mRNA) contains codons for protein sequences

⊳ encodes amino acid sequences interrupting sequences

introns ⊳ noncoding portion of a gene

exons ⊳ coding portion of a gene

processing cap

⊳ added to 5’ end (guanine nucleotide) teai

⊳ added to 3’ end (Poly­A tail of 50­250 adenines) RNA splicing

removal of introns and joining of exons to produce a continuous sequence ⊳ cut and paste

Transfer RNA molecules serve as interpreters during translation transfer RNA (tRNA)

matches amino acids to corresponding mRNA codon ⊳ converts one “language” to the next

trasks: ⊳ 1) pick up amino acids (attachment site) ⊳ 2) match to specific mRNA codon

made possible by the anticodon base pairing rules

Ribosomes build polypeptides ribosomal RNA (rRNA)

ribosomes have 2 subunits, each made of rRNA and protein

⊳ come together during translation (binding sites for m and tRNA)

moving to the left in this picture

Initiation codon marks the start of an mRNA message 1) mRNA binds to small ribosomal subunit

special tRNA binds to specific start codon (translation begins on mRNA) 2) large ribosomal subunit binds to small one, creating a functional ribosome

initiator tRNA fits into one of the two binding sites ⊳ P site: holds growing polypeptide

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⊳ A site: vacant, ready for next tRNA

Click here for a quick animation which will complete your understanding: ⊳ Digital Study Guide Link ⊳ http://tiny.cc/ProteinSynthesis (Case Sensitive)

Elongation adds amino acids to the chain until a stop codon terminates translation 1) Codon recognition

upcoming tRNA binds to the mRNA at the A site 2) Peptide bond formation

A.A.’s on the tRNA at the P site are attached by a covalent bond to the amino acid on the tRNA at the A site

3) Translocation tRNA is released from the P site and the ribosome moves tRNA from the

A site into the P site stop codon

UUA, UAG, and UGA ⊳ act as signals to stop translation

Termination completed polypeptide is released

Mutations can change the meaning of genes mutation

⊳ change in the nucleotide sequence of DNA base substitutions

⊳ replace one nucleotide with another deletions/insertions

⊳ alter reading frame of mRNA so groupings are wrong ⊳ significant changed down the line

nonfunctional polypeptide spontaneous or induced

radiation and chemicals induce mutation errors in DNA replication/recombination

Microbial Genetics

Viral DNA may become part of the host chromosome viruses

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“genes in a box” ⊳ capsid is a protein shell enclosing viral genome

lytic cycle results in lysis of the host cell and release of viruses

⊳ virus particles produced using host cell materials ⊳ breaking open = lysis

lysogenic cycle ⊳ injects DNA and allows to multiply [the newly bad cells]

viral DNA is inserted into host by recombination viral DNA is duplicated during cell division

⊳ prophage Many viruses cause disease in animals and plants

viruses can be RNA or DNA view diagram to right for details

Emerging viruses threaten human health emerging viruses

appears suddenly or recently comes to attention of medics ⊳ mutation, cross­species contact, spread from isolation

Examples: HIV, ebola, west nile, etc..

AIDS makes DNA on RNA template caused by HIV

human immunodeficiency virus retrovirus

2 copies of RNA genome reverse transcriptase

⊳ synthesis of DNA on RNA template Viroids and prions

viroids: circular RNA molecules that infect plants interfere w/ plant growth

prions: infectious proteins that cause brain diseases in animals Bacterial transfer of DNA

1) transformation uptake of foreign DNA from surround environment

⊳ “leftovers” 2) transduction

gene transfer thru phages 3) conjugation

transfer of DNA from a donor to recipient bacterial cell ⊳ “cell mating” (donor cell gives to recipient cell)

TOPIC 11: HOW POPULATIONS EVOLVE

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Darwin’s Theory of Evolution A sea voyage aboard the HMS Beagle

natural selection differential survival and reproduction of individuals within a population

Aristotle: species are perfect and unchanging fossil study

suggests change over time Lamarck: use and disuse ; inheritance of acquired characteristics

giraffes stretching necks Lyell’s Principles of Geology was a big influence on Darwin

realized earth was very old On the Origin of Species by Means of Natural Selection

descent with modification theory Alfred Wallace had very similar theory

Darwin proposed natural selection as the mechanism of evolution traits that increase chance of survival and reproduction leave more offspring

favorable traits accumulate in a population of generations artificial selection

selective breeding of domesticated plants and animals mustard seed

NATURAL SELECTION populations evolve, not individuals can amplify or diminish heritable traits

acquired characteristics cannot be passed down evolution is not goal directed and doesn’t lead to perfection

Malthus disease, famine, and war = consequences

populations growing too fast Scientists can observe natural selection in action

Rosemary and Peter Grant Galápagos finches beak size

pesticide resistance the resistant ones reproduce

Fossil study as evidence oldest fossils: prokaryotes

oldest eukaryotes are 1 billion years younger multicellular fossils more recent

generational links extinct species linked with species living today (ex: whale)

Other evidence biogeography

geographic distribution of species… organisms evolve from common ancestors

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animals on islands resemble mainland more than other islands of other continents

comparative anatomy comparison of body structures among species homology: similarity in characteristics from

common ancestry vestigial organs: no importance to the organism

comparative embryology comparision of early stages of development

molecular biology comparison of DNA and amino acid sequences

everything shares common DNA Homologies indicate patterns of descent that can be shown on an evolutionary tree

evolutionary tree a branching diagram that reflects a hypothesis about evolutionary

relationship among groups of organisms determine branching sequence Darwin was first to use this method

Evolution of Populations

Populations are units of eovlution population: group of individuals of the same species living in the same place at

the same time evolution is the change in heritable traits over generations in a population interbreeding/no interbreeding (mate w/ other populations)

gene pool: all the alleles for all the genes in a population microevolution: changes in relative frequencies of alleles in a population population genetics studies how populations change genetically modern synthesis theory

connection of Darwinism with population genetics Mutation & Sexual Reproduction producing variation

mutation: changes in nucleotide sequence of DNA ultimate source of new alleles

can sometimes help (resistance to something) sexual reproduction: shuffles alleles to produce new combinations

during meiosis chromosomal duplication

copy can appear and mutate w/o affecting original gene Hardy­Weinberg equation tests whether a population is evolving

Hardy­Weinberg equilibrium principle that shuffling of genes during sexual reproduction by itself

cannot change overall genetic makeup of a population outside forces must act

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Requirements for HW: large population no gene flow between populations no mutations random mating no natural selection

Useful in public health science estimate frequencies of disease causing alleles in humans

Mechanisms of Microevolution

Alteration of population frequencies natural selection

if there is differentiation of survival/reproductive success genetic drift

change in gene pool due to chance could be loss of genetic diversity

bottleneck effect reduction in population size resulting in loss of genetic diversity

founder effect few individuals colonize a new habitat

smaller the group = more diversity gene flow

movement of individuals between populations Natural Selection is only mechanism that consistently leads to adaptive evolution

fitness: contribution an individual makes to the gene pool of the next generation those who are more fit pass on most genes/offspring

Natural selection can alter variation stabilizing selection: favors intermediate phenotypes directional selection: acts against individuals at one end of phenotype extremes disruptive selection: favors both extremes of phenotypic range

Sexualselection may lead to phenotypic differences in gender sexual dimorphism: distinct differences in appearance between sexes intrasexual competition: competition for mates

most often by males intersexual competition: mate choice

usually females are picky choosers of their mates (color and flashy) sexual selection

Antibiotic resistance in bacteria

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natural selection is favoring bacteria because of excessive antibiotic use common in hospitals

infections starting in hospitals are usually resistant TOPIC 12: THE IMMUNE SYSTEM Immune Defenses Against Infecton

Both invertebrates and vertebrates have innate defenses against infection innate immunity: first line of defense against potential invaders

the same response whether invader has been encountered before or not ⊳ skin, mucous membranes, phagocytic cells, antimicrobial proteins

invertebrates have only innate immunity vertebrates also have acquired immunity

vertebrate innate immunity: ⊳ macrophages: large phagocytic cells eating any bacteria and virus

infected cells ⊳ NK cells: white blood cells that attack cancer and virus­infected

cells by releasing chemicals ⊳ interferons: proteins produced by virus­infected cells that help

other cells resist viruses Inflammatory response

inflammatory response is part of innate immunity triggered by any damage to tissue

⊳ 1) release chemical alarm signals like histamine ⊳ 2) blood vessels dilate and leak ⊳ 3) phagocytes “Eat” bacteria

Lymphatic system is a battleground during infection lymphatic system: lymph vessels, nodes, and spleen, etc…

removes toxins and pathogens from the blood ⊳ 1) return tissue fluid to circulatory system ⊳ 2) fight infection

lymphatic vessels: collect fluid from body tissues and return it as lymph to the blood

lymph organs: packed with white blood cells that fight infection as lymph circulates through organs…

carries microbes, parts of microbes, and/or microbe toxins bring these to the lymphatic organs

⊳ macrophages waiting there engulf invaders ⊳ may cause an acquired immune response

Acquired Immunity Acquired immune response counters specific invaders

acquired immunity only in vertebrates only occurs after exposure to pathogens (usually natural)

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remembers an invader ; reacts to antigens active immunity

triggered by infection or vaccination ⊳ immunization: harmless variant of a disease to stimulate immune

response so it will respond quickly in a real situation passive immunity

acquire by receiving pre­made antibodies (temporary) antigen: any foreign molecule that elicits an acquired immune response antibody: protein that attaches to a certain antigen and helps counter effects

Lymphocytes mount a dual defense lymphocytes

⊳ white blood cells in the tissues and organs of lymphatic system ⊳ responsible for acquired immune response

B cells matures in bone marrows

⊳ secret antibodies and ⊳ mount humoral immune response

T cells matures in thymus

⊳ attack cells infected with bacteria or viruses ⊳ cell­mediated immune response

Antigens have specific regions where antibodies bind to them antigenic determinant (epitope)

specific regions on an antigen ⊳ where the antibodies bind

antigen binding site spot on antibody

⊳ recognizes antigenic determinants like a lock and key

Clonal selection musters defensive forces against certain antigens

antigens only trigger certain lymphocytes the ones with complementary receptors

⊳ these certain lymphocytes multiple into clones specialized in defense against the certain antigen are effector cells and memory cells

clonal selection primary immune response (first exposure)

slower than 2nd ⊳ produces effector cells (fight now) ⊳ memory cells (lifeling immunity)

secondary immune response (second exporsure) faster than 1st

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⊳ memory cells activated ⊳ faster and stronger response

Summary 1) antigen enters body 2) antigenic determinants bind to the few B cells that it complements 3) selected cells are activated: they grow and divide 4) effector cells are produced (aka plasma cells)

⊳ secrete antibodies to attack antigen 5) memory cells are produced (last for decades)

⊳ stay in lymph nodes Antibodies are the weapons of the humoral immune response

antibodies produced by plasma cells (effector cells) Y­shaped

⊳ two antigen­binding sites (recognition and binding) Antibodies mark antigens for elimination

neutralization block virus, disabling ability to infect host cell enhance macrophage destruction

agglutination clumps together so it is easy to be engulfed

precipitation link dissolved antigen molecules together

activation of complement system pokes holes in foreign cells’ plasma membrane

⊳ causes cell lysis/rupture Monoclonal antibodies (mAb)

research, diagnosis, cancer treatment all antibody­producing cells from one cell made by fusing in home pregnancy tests (HCG)

Helper T cells stimulate humoral and cell­mediated responses cytotoxic T cells

attack body cells infected with pathogens Helper T cells

activate cytotoxic T cells and macrophages ⊳ stimulate B cell antibody secretion

antigen­presenting cells presents a foreign antigen to helpter T cell

⊳ self protein: protein on the surface of a presenting cell that holds foreign antigens, displaying them to helper T cells

nonself molecules: foreign antigen

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Helper T cell receptors ⊳ recognize self­nonself complexes, activate Helper T cells

then activates Cytotoxic T cells and B cells Cytotoxic T cells destroy infected body cells

only type of T cell that kills infected cells ⊳ 1) binds to infected cells (release perforin) ⊳ 2) perforin attached to cell membrane, making holes ⊳ 3) infected cell dies and is destroyed

HIV destroys helpter T cells AIDS (acquired immunodeficieny syndrome)

comes from HIV (always use protection, kids) the attack

reverse­transcribes into Helper T cell, eventually it dies ⊳ cell­mediated and humoral is impaired

opportunistic infection ⊳ can be controlled by normal immune systems

causes them to die complicated treatment

HIV mutates too fast ⊳ new strains are already resistant to drugs ⊳ AIDS and HIV = incurable

Immune system depends on molecular fingerprints transplanted organs

may be rejected by body because they don’t match the body’s ‘fingerprint’ ⊳ which is why you want a closely matched donor

Disorders on the Immune System Malfunction or failure of immune system

autoimmune disease immune system turns against itself

⊳ lupus, rheumatoid arthritis, diabetes, sclerosis immunodeficiency diseasy

lack a component of the immune system ⊳ susceptible to infection

regular weakenings physical stress emotional stress

⊳ ex) during exam week allergies

hypersensitive responses to antigens in our surrounds respond to allergens

antihistamines interfere with histamine, temporary allergy relief

⊳ induce drowsiness

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anaphylatic shock very dangerous reaction

⊳ mast cells release inflammatory chemicals quickly ⊳ rapid drop in blood pressure

reversed by epinephrine (epi­pen) TOPIC 13: HORMONES AND THE ENDOCRINE SYSTEM The Nature of Chemical Regulation

Chemical signals coordinate body functions hormone

chemical signal carried by circulatory system in blood communicates regulatory message throughout body

⊳ secreted by: endocrine glands and neurosecretory cells target cells respond to hormones

endocrine system all of hormone­secreting cells

⊳ works in association w/ nervous system to maintain homeostasis

communicates, regulates, uses electrical signals via nerve cells comparing

nervous system: faster endocrine system: both takes and lasts longer

neurosecretory cells functions in both systems

⊳ conduct nerve signals, make and secrete hormones Hormones affect target cells by two main signaling mechanism

hormone signaling involves 3 events: reception: hormone binds to receptor protein signal transduction: series of changes in relay molecules response: final relay molecule activates a protein to carry out response in

cytoplasm or nucleus amino­acid hormones

water soluble ⊳ proteins, peptides, and amines

bind to plasma­membrane receptors on target cells initate a signal transduction pathway

steroid hormones ⊳ ex) testosterone and estrogen

made from cholesterol nonpolar lipids

⊳ diffuse thru plasma membranes ⊳ bind to a receptor protein

Vertebrate Endocrine System

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Vertebrate endocrine system and glands more than a dozen glands which secret 50+ hormones glands

specialized for hormone secretion or other jobs Hypothalamus, closely tied to pituitary, connects nervous and endocrine systems

hypothalamus master control center of the system

maintains homeostasis by coordinating endocrine and nervous systems

uses pituitary gland pituitary gland

posterior pituitary nervous tissue secretes oxytocin and ADH

anterior pituitary endocrine cells

synthesize and secrete hormones controlled by hypothalamus

releasing hormones: stimulate inhibiting hormones: inhibit

Hormones and Homeostasis The thyroid regulates development and metabolism

thyroid gland under larynx secrets:

⊳ thyroxine (T4) ⊳ triiodothyronine (T3)

regulate metabolism and development negative feedback

⊳ maintain homeostatic levels of T4 and T3 in blood thyroid imbalance

hyperthyroidism ⊳ too much t4 and t3

high blood pressure, weight loss, overheat, irritability, Graves’ disease (eyes)

hypothyroidism ⊳ too little T4 and T3

low blood pressure, overweight, cold, lethargy, GOITER Hormones from the thyroid and parathyroids maintain calcium homeostasis

calcium levels regulated by anatagonisms calcitonin: lowers calcium level parathyroid hormone (PTH): raises calcium level

Pancreatic hormones and blood glucose levels

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Tommy Wiaduck 2015

pancreas ⊳ secrets two hormones which regulate blood glucose

insulin: lowers level of glucose in blood glucagon: raises level of glucose in the blood

diabetes lack of insulin or failure of cells to respond to it

⊳ Type 1: autoimmune disease insulin dependent (cells destroyed)

⊳ Type 2: fat overweight and underactive, reduced response to insulin

Adrenal Glands mobilize stress responses adrenal glands

hypothalamus stimulates secretion of: ⊳ epinephrine and norepinephrine

fight or flight adrenocorticotropic hormone (ACTH) causes secretion of

⊳ glucocorticoids and mineralocorticoids boost blood pressure and energy in response to long­term

stress The gonads and sex hormones

steroid sex hormones estrogens, progestins, and androgens

⊳ made by gonads (sex organs) by hypothalamus and pituitary

estrogens and progestins ⊳ female characteristics and female reproduction

androgens ⊳ testosterone ; male characteristics

1 hormone, many functions prolactin

⊳ does different for humans and other animals humans: grow and produce milk mammals: nest building birds: fat metabolism and reproduction amphibians: movement to water fish: migration between salt and fresh water

TOPIC 14: REPRODUCTION AND EMBRYONIC DEVELOPMENT Asexual and Sexual Reproduction

fertility drugs increase ovulated eggs

increase chance of multiple births risks: premature, lower weight, mortality

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Tommy Wiaduck 2015

asexual reproduction one parent with genetically identical offspring

budding: splitting off new individuals from existing ones fission: separation of parent into 2+ individuals fragmentation: breaking of the parent body into several pieces,

which develop into complete adults regeneration: regrowth of lost body parts

sexual reproduction fusion of gametes from two parents

genetic variation gametes: haploid sex cell

diploid zygote hermaphroditism

one individual with male and female reproductive systems fertilization

external fish and amphibians ; sperm discharged nearby

internal sperm discharged in or near female reproductive tract

Human Reproduction ­ Female Human Female

ovaries female gonad which produces egg cells and reproduction hormones follicles

cluster of cells which protect developing eggs in the ovary

ovulation

release of an egg from ovarian follice (~28 day cycle) oviduct (fallopian tube) (uterine tube)

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Tommy Wiaduck 2015

tube that conveys egg cells away from ovary cilia moves the egg

uterus womb ; site of pregnancy expandsduring pregnancy endometrium

inner lining of uterus cervix

opens into vagina cervical cancer (curable if caught early)

episiotomy incision from vagina to anus hole to fit big melon head baby

C section clitoris

fills with blood and erects during sexual arousal vaginal opening

hymen (maidenhood): breaks Human Male

testes start in abdomen, descend (gubernaculum)

epididymis stores sperm as they develop

sperm lives about 72 hours… heat kills them seminiferous tubule

spermatogenesis occurs here vas deferens

part of the male that conveys sperm away from testes “sperm duct”’ vasectomy: suture and burn with a heat gun

bulbourethral goes right to urethra creates fluid that lubricates and neutralizes acids during sex

prostrate gland adds fluid which neutralized acidity of urinary fluids (lowers pH)

so sperm can live seminal vesicle

adds fructose (swim energy) and lubricant (easy to swim) Formation of sperm and egg

need meiosis spermatogenesis oogenesis

primary and secondary Menstrual Cycle

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Tommy Wiaduck 2015

28 day cycle follicle (egg being developed)

once ovulated → copus luteum Hormones

Follicle­Stimulating Hormone (FSH) stimulates growth of the ovarian follicle

produces egg Estrogen & Progesterone

maintain endometrium (thicken lining) wait for egg to plant itself

Luteinizing Hormone (LH) growth of ovarian follice and production of ova

releases egg promotes ovulation promotes development of corpus luteum and secretion of

hormones Egg can be fertilized for 24­48 hours

you can always get pregnant, there is never no chance Fertilization

takes 7­8 days to reach uterus (cells change during this) zillions of sperm

goal: fertilize egg sperm must get to “jelly coat”

acrosomes must find correct receptors Cleavage

rapid succession of cell divisions that produces a ball of cells blastula

hollow ball of cells after end of cleavage gastrulation

transforms blastula into a gastrula ectoderm: skin and nervous system (outside) endoderm: digestive tract (inside) mesoderm: muscle and bone (middle layers)

organ formation notochord: flexible rod located between digestive tract and nerve chord

beginning of the backbone neural tube: gives rise to the brain and spinal cord

brain and spinal cord Five P’s

1) passenger how much is she dilated, water broke, head size, gestational age, attitude,

number of fetuses 2) passageway

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Tommy Wiaduck 2015

configuration, diameter, and shape of pelvis 3) powers

primary: intensity, duration, frequency (of contractions) not controllable

secondary: push and excell the fetus controlled by woman

4) position in water, midwife, hospital, squat, hands and knees

5) phsychological response are you ready? financial stressors? how many babies? location?

Weird Birth Stuff head and brain keep growing after birth

fontanels: growing space (squishy)(cartilage) unnatural birth (epidural)

paralyzes you waste­down inject spine w/ paralytic

episiotomy incision near vagina to anus hole

suture up after birth Topic 14 was lightly covered because it should be somewhat fresh in your brain. Refer to the question list to study the information you need. Good luck!

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