Exam 1 Study Guide Natural Science Biology Lecture Hollingsworth (Phelan, Chapters 1-3)

1. HollingsworthBiologyExam1StudyGuide 09/06/2014
Chapter 1
Biology
Biological Literacy
Superstitions
Scientific discipline
What does empirical mean?
Can scientists change their minds?
Steps of the scientific method
Observations
Hypotheses
Predictions
Theories
Laws
Placebo
Echinacea example
Experiment
Testable
Scientific theory (and how it differs from the common use of the word theory
Controlled experiments
Double-blind study
Treatment group v. Control Group
Why do scientists use statistics?
Anecdotal evidence
What is pseudoscience?
Branches of science
Systems of nature
What cannot be answered using the scientific method?
Chapter 2
Element
Atom
Protons
Neutrons
Electrons
Nucleus
How many different elements are found in your body?
Atomic number
Atomic mass
Four most abundant elements in the human body
Ion
Ionic bond
Covalent bond

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Hydrogen bond
Molecules
Why do certain chemicals have certain tastes?
Importance of water
Coastal climates v. Inland climates
pH
Acidity
Base/alkalinity
Carbohydrates
Lipids
Proteins
Nucleic acids
Monosaccharides
Insoluble fiber
Hydrocarbons
Cell membranes
DNA sequences
DNA – RNA
Nucleotides
Chapter 3
Plant cell
Animal cell
Similarities and differences
Cell organelles (names and general functions)
Cell wall, cell membrane, plasma membrane
Prokaryotic
Eukaryotic
Cell theory
Youtube Videos – watch them again! Review your notes. Re-write your notes. Study! Focus!
https://www.youtube.com/channel/UCERU5ulJjCLZSwlRPZ7kgYw
Here is a general outline of the three chapters in unit one, which will be on the first exam. If you
are looking for the concepts, this will help you look!
Chapter 1
Scientific Thinking
Chapter Outline

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1 Science is a collection of facts and a process for
understanding the world.
1.1 What is science? What is biology?
TAKE-HOME MESSAGE 1.1: Through its emphasis on objective observation, description, and
experimentation,science isapathwaybywhichwe candiscoverandbetterunderstandthe world
around us.
1.2 Biological literacy is essential in the modern world.
TAKE-HOME MESSAGE 1.2: Biological issues permeate all aspects of our lives. To make wise
decisions, it is essential for individuals and societies to attain biological literacy.
1.3 The scientific method is a powerful approach to understanding the world.
TAKE-HOME MESSAGE 1.3: There are numerouswaysof gainingan understandingof the world.
Because itis empirical,rational,testable,repeatable,andself-correcting,the scientificmethodis
a particularly effective approach.
2 A beginner’s guide: what are the steps of the scientific
method?
1.4 Thinking like a scientist: how do you use the scientific method?
TAKE-HOME MESSAGE1.4: The scientificmethod(observation,hypothesis,prediction,test,and
conclusion) isaflexible,adaptable,andefficientpathwaytounderstandingthe world,because it
tells us when we must change our beliefs.
1.5 Step 1: Make observations.
TAKE-HOME MESSAGE1.5: The scientificmethodbeginsbymakingobservationsaboutthe world,
noting apparent patterns or cause-and-effect relationships.
1.6 Step 2: Formulate a hypothesis.
TAKE-HOME MESSAGE1.6: A hypothesisisaproposedexplanationforanobservedphenomenon.
1.7 Step 3: Devise a testable prediction.
TAKE-HOME MESSAGE 1.7: Fora hypothesistobe useful,itmustgenerateatestable hypothesis.
1.8 Step 4: Conduct a critical experiment.

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TAKE-HOME MESSAGE 1.8: A critical experiment is one that makes it possible to decisively
determine whether a particular hypothesis is correct.
1.9 Step 5: Draw conclusions, make revisions.
TAKE-HOME MESSAGE1.9: Basedonthe resultsof experimental tests,wecanreviseahypothesis
and explainthe observable worldwithincreasingaccuracy.A great strengthof scientificthinking,
therefore, is that it helps us understand when we should change our minds.
1.10 When do hypotheses become theories, and what are theories?
TAKE-HOME MESSAGE1.10: Scientifictheoriesdonotrepresentspeculationorguessesaboutthe
natural world. Rather, they are hypotheses—proposed explanations for natural phenomena—
thathave beensostronglyandpersuasivelysupportedbyempirical observationthatthe scientific
community views them as very unlikely to be altered by new evidence.
3 Well-designed experiments are essential to testing
hypotheses.
1.11 Controllingvariablesmakesexperimentsmore powerful.
TAKE-HOME MESSAGE 1.11: To draw clear conclusionsfromexperiments,itisessential tohold
constantall those variableswe are notinterestedin.Control andexperimental groupsshould
differonlywithrespecttothe treatmentof interest.Differencesinoutcomesbetweenthe
groupscan thenbe attributedtothe treatment.
1.12 Repeatableexperimentsincreaseourconfidence.
TAKE-HOME MESSAGE 1.12: Experimentsandtheiroutcomesmustbe repeatable fortheir
conclusionstobe consideredvalidandwidelyaccepted.
1.13 We’ve gotto watchout for our biases.
TAKE-HOME MESSAGE 1.13: Biasescan influence ourbehavior,includingourcollectionand
interpretationof data.Withcareful controls,itispossibletominimize suchbiases.
4 The scientific method can help us make wise decisions.
1.14 Visual displays of data can help us understand and explain phenomena.
TAKE-HOME MESSAGE 1.14: Visual displaysof data,whichcondense large amounts
of information,canaidinthe presentationandexplorationof the data.The effectiveness
of suchdisplaysisinfluencedbythe precisionandclarityof the presentation,anditcan be
reducedbyambiguity,biases,hiddenassumptions,andotherissuesthatreduce a viewer’s
confidence inthe underlyingtruthof the presentedphenomenon.

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1.15 Statistics can help us in making decisions.
TAKE-HOME MESSAGE 1.15: Because much variationexistsinthe world,statistics
can helpusevaluate whetheranydifferencesbetweenatreatmentgroupanda control group
can be attributedtothe treatmentratherthanrandom chance.
1.16 Pseudoscience and misleading anecdotal evidence can obscure the truth.
TAKE-HOME MESSAGE 1.16: Pseudoscienceandanecdotal observationsoftenlead
people tobelieve thatlinksbetweentwophenomenaexist,wheninfactthere are nosuch
links.
1.17 There are limitstowhatscience can do.
TAKE-HOME MESSAGE 1.17: Althoughthe scientificmethodmaybe the most
effectivepathtowardunderstandingthe observableworld,itcannotgive usinsightsinto
the generationof value judgmentsandothertypes of non-quantifiable,subjective
information.
5 On the road to biological literacy: what are the major themes
in biology?
1.18 A few important themes tie together the diverse topics in biology.
TAKE-HOME MESSAGE 1.18: Although the diversityof life on earth is tremendous, the study of
life is unified by the themes of hierarchical organization and the power of evolution.
Chapter 2
Chemistry
Chapter Outline
1 Atoms form molecules through bonding.
2.1 Everything is made of atoms.
TAKE-HOME MESSAGE 2.1: Everythingaroundus,livingornot,ismade upof atoms,the smallest
unitsintowhichmaterialcanbe dividedwithoutlosingitsessentialproperties.Allatomshavethe
same general structure.Theyare made upof protonsandneutronsinthe nucleus,and electrons,
which circle far and fast around the nucleus.

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2.2 An atom’s electrons determine how (and whether) the atom will bond with other atoms.
TAKE-HOME MESSAGE 2.2: The chemical characteristics of an atom depend on the number of
electronsinitsoutermostshell.Atomsare moststable andleastlikelytobondwithotheratoms
when their outermost electron shell is filled to capacity.
2.3 Atoms can bond together to form molecules or compounds.
TAKE-HOME MESSAGE2.3: Atomscanbe boundtogetherinthreedifferentways.Covalentbonds
occur whenatomsshare electrons.Inionicbonds,oneatomtransfersitselectronstoanotherand
the two oppositely charged ions are attracted to each other, forming a compound. Hydrogen
bonds, which are weaker than covalent and ionic bonds, involve the attraction between a
hydrogen atom and a polar molecule.
2 Water has features that enable it to support all life.
2.4 Hydrogen bonds make water cohesive.
TAKE-HOME MESSAGE 2.4: Water molecules easily form hydrogen bonds, giving water great
cohesiveness.
2.5 Water has unusual properties that make it critical to life.
TAKE-HOME MESSAGE 2.5: The hydrogenbondsbetweenwatermoleculesgive waterseveral of
its most important characteristics,including cohesiveness,reduced densityas a solid, the ability
toresisttemperaturechanges,andbroadeffectivenessasasolventforionicandpolarsubstances.
2.6 Living systems are highly sensitive to acidic and basic conditions.
TAKE-HOME MESSAGE 2.6: The pH of a fluid is a measure of how acidic or basic the solution is
anddependsonthe concentrationof dissolvedH+
ionspresent.Acids,suchasvinegar,candonate
protons to other chemicals; bases, including baking soda, bind with free protons.
3 Carbohydrates are fuel for living machines.
2.7 Carbohydrates include macromolecules that function as fuel.
TAKE-HOME MESSAGE 2.7: Carbohydratesare the primaryfuel forrunningall cellularmachinery
and also form much of the structure of cells in all life forms. Carbohydrates contain carbon,
hydrogen, and oxygen, and generally have the same number of carbon atoms as they do H2O
units.The simplestcarbohydrates,includingglucose,are monosaccharidesorsimple sugars.They
containfromthree tosix carbonatoms.Asthe chemicalbondsof carbohydratesare brokendown
and other more stable bonds are formed, a great deal of energy is released that can be used by
organisms.
2.8 Glucose provides energy for the body’s cells.

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TAKE-HOME MESSAGE 2.8: Glucose is the most important carbohydrate to living organisms.
Glucose in the bloodstream can be used as an energy source, can be stored as glycogen in the
muscles and liver for later use, or can be converted to fat.
2.9 Many complex carbohydrates are time-released packets of energy.
TAKE-HOME MESSAGE 2.9: Multiple simple carbohydrates are sometimes linked together into
more complex carbohydrates. Types of complex carbohydrates include starch, which is the
primaryformof energystorage inplants,and glycogen,whichisaprimaryformof energystorage
in animals.
2.10 Not all carbohydrates are digestible.
TAKE-HOME MESSAGE 2.10: Some complex carbohydrates,includingchitinandcellulose,cannot
be digested by most animals. Such indigestible carbohydrates in the diet, called fiber, aid in
digestion and have many health benefits.
4 Lipids store energy for a rainy day.
2.11 Lipids are macromolecules with several functions, including energy storage.
TAKE-HOME MESSAGE 2.11: Lipids are insoluble in water and greasy to the touch. They are
valuable toorganismsforlong-termenergystorage andinsulation,inmembrane formation,and
as hormones.
2.12 Fats are tasty molecules too plentiful in our diets.
TAKE-HOME MESSAGE2.12: Fats,includingthe triglyceridescommoninthe foodwe eat,are one
type of lipid. Characterized by long hydrocarbon tails, fats effectively store energy in the many
carbon-hydrogen and carbon-carbon bonds. Their caloric density is responsible for humans’
preferring fats to other macromolecules in the diet, and is also responsible for their association
with obesity and illness in the modern world.
2.13 Cholesterol and phospholipids are used to build sex hormones and membranes.
TAKE-HOME MESSAGE 2.13: Cholesterol andphospholipidsare lipidsthatare not fats. Both are
important components in cell membranes. Cholesterol also serves as a precursor to steroid
hormones, important regulators of growth and development.
5 Proteins are versatile macromolecules that serve as
building blocks.
2.14 Proteins are bodybuilding macromolecules.

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TAKE-HOME MESSAGE 2.14: Unique combinations of 20 amino acids give rise to proteins, the
chief building blocks of the physical structures that make up all organisms. Proteins perform
myriadfunctions,fromassistingchemicalreactionstocausingbloodclottingtobuildingbonesto
fighting microorganisms.
2.15 Proteins are an essential dietary component.
TAKE-HOME MESSAGE2.15: Twentyaminoacids make up all the proteinsnecessaryforgrowth,
repair, and replacement of tissue in living organisms. Of these amino acids, about half are
essential forhumans:theycannot be synthesizedbythe body so must be consumedin the diet.
Complete proteins contain all essential amino acids, while incomplete proteins do not.
2.16 A protein’s function is influenced by its three-dimensional shape.
TAKE-HOME MESSAGE 2.16: The particular aminoacid sequence of a proteindetermineshowit
folds into a particular three-dimensional shape. This shape determines many of the protein’s
features, such as the moleculesit will interact with. When a protein’s shape is deformed,the
protein usually loses its ability to function.
2.17 Enzymes are proteins that initiate and speed up chemical reactions.
TAKE-HOME MESSAGE 2.17: Enzymes are proteins that help initiate and speed up chemical
reactions.Theyaren’tpermanentlyalteredinthe process,butrathercanbe usedagainandagain.
2.18 Enzymes regulate reactions in several ways (but malformed enzymes can cause
problems).
TAKE-HOME MESSAGE2.18: Enzyme activityisinfluencedbyphysical factorssuchastemperature
and pH, as well as chemical factors, including enzyme and substrate concentrations. Inhibitors
and activators are chemicalsthatbind to enzymesandby blockingthe active site or alteringthe
shape or structure of the enzyme canchange the rate at which the enzyme catalyzes reactions.
6 Nucleic acids store the information on how to build and
run a body.
2.19 Nucleic acids are macromolecules that store information.
TAKE-HOME MESSAGE 2.19: The nucleic acids DNA and RNA are macromolecules that store
information in their unique sequences of bases contained in nucleotides, their building-block
molecules. Both nucleic acids play central roles in directing protein production in organisms.
2.20 DNA holds the genetic information to build an organism.
TAKE-HOME MESSAGE 2.20: DNA islike a ladderinwhichthe longvertical sidesof the ladderare
made froma sequence of sugar-phosphate-sugar-phosphatemoleculesandthe rungsare pairsof

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nucleotide bases. The sequence of nucleotide bases contains the information about how to
produce a particular protein.
2.21 RNA is a universal translator, reading DNA and directing protein production.
TAKE-HOME MESSAGE 2.21: RNA acts as a middleman molecule—taking the instructions for
protein production from DNA to another part of the cell where, in accordance with the RNA
instructions, amino acids are pieced together into proteins.
Chapter 3
Cells
Chapter Outline
1 What is a cell?
3.1 All organismsare made of cells.
TAKE-HOME MESSAGE 3.1: The mostbasicunitof any organismisthe cell,the smallestunitof
life thatcan functionindependentlyandperformall of the necessaryfunctionsof life,including
reproducingitself.All livingorganismsare made upof one or more cells,andall cellsarise from
other,pre-existingcells.
3.2 Prokaryoticcellsare structurallysimple,butthere are manytypesof them.
TAKE-HOME MESSAGE 3.2: Everycell on earthiseithera eukaryoticora prokaryoticcell.
Prokaryotes,whichhave nonucleus,werethe firstcellsonearth.Theyare all single-celled
organisms.Prokaryotesinclude the bacteriaandarchaeaand,as a group,are characterizedby
tremendousmetabolicdiversity.
3.3 Eukaryoticcellshave compartmentswithspecializedfunctions.
TAKE-HOME MESSAGE 3.3: Eukaryotesare single-celledormulticellularorganismsconsistingof
cellswithanucleusthatcontainslinearstrandsof geneticmaterial.The cellsalsocommonly
have organellesthroughouttheircytoplasm;these organellesmayhave originated
evolutionarilythroughendosymbiosisorinvagination,orboth.
2 Cell membranes are gatekeepers.

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3.4 Everycell isborderedbya plasmamembrane.
TAKE-HOME MESSAGE 3.4: Everycell of everylivingorganismisenclosedbyaplasma
membrane,atwo-layeredmembranethatholdsthe contentsof acell inplace and regulates
whatentersand leavesthe cell.
3.5 Moleculesembeddedinthe plasmamembrane helpitperformitsfunctions.
TAKE-HOME MESSAGE 3.5: The plasmamembrane isafluidmosaicof proteins,lipids,and
carbohydrates.Proteinsfoundinthe plasmamembrane enable ittocarry outmost of its
gatekeepingfunctions.The proteinsactas receptors,helpmoleculesgainentryintoandexit
fromthe cell,andcatalyze reactionsonthe innerandoutercell surfaces.Inconjunctionwith
carbohydrates,some plasmamembrane proteinsidentifythe cell toothercells.And,inaddition
to the phospholipidsthatmake upmostof the plasmamembrane,cholesterol isanimportant
lipidinsome membranes,influencing fluidity.
3.6 Faultymembranescancause disease.
TAKE-HOME MESSAGE 3.6: Normal cell functioningcanbe disruptedwhencell membranes—
particularlythe proteinsembeddedinthem—donotfunctionproperly.Suchmalfunctionscan
cause healthproblems,such ascysticfibrosis.Butdisruptionof normal cell membrane function
can alsohave beneficial,therapeuticeffects,suchasinthe treatmentof highbloodpressure
and anxiety.
3.7 Membrane surfaceshave a “fingerprint”thatidentifiesthe cell.
TAKE-HOME MESSAGE 3.7: Everycell inyour bodyhas a “fingerprint”made fromavarietyof
moleculesonthe outside-facingsurface of the cell membrane.Thismolecularfingerprintiskey
to the functionof yourimmune system.
3 Molecules move across membranes in several ways.
3.8 Passive transportisthe spontaneousdiffusionof moleculesacrossamembrane.
TAKE-HOME MESSAGE 3.8: For properfunctioning,cellsmustacquire foodmoleculesand/or
othernecessarymaterialsfromoutsidethe cell.Similarly,metabolicwaste moleculesand
moleculesproducedforuse elsewhere inthe bodymustmove outof the cell.Inpassive
transport—whichincludessimple andfacilitateddiffusionandosmosis—themolecular
movementoccursspontaneously,withoutthe inputof energy.Thisgenerallyoccursas
moleculesmovedowntheirconcentrationgradient.
3.9 Osmosisisthe passive diffusionof wateracrossa membrane.
TAKE-HOME MESSAGE 3.9: The diffusionof wateracrossa membrane isa special type of
passive transportcalledosmosis.Watermoleculesmoveacrossthe membrane until the
concentrationof waterinside andoutside the cell isequalized.

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3.10 Inactive transport,cellsuse energytomove small moleculesintoandoutof the cell.
TAKE-HOME MESSAGE 3.10: In active transport,movingmoleculesacrossamembrane requires
energy.Active transportisnecessaryif the moleculestobe movedare verylarge or if theyare
beingmovedagainsttheirconcentrationgradient.Proteinsembeddedinthe plasmamembrane
act like motorizedrevolvingdoorstoactivelytransport(pump) the molecules.
3.11 Endocytosisandexocytosisare usedforbulktransportof particles.
TAKE-HOME MESSAGE 3.11: When materialscannotgetintoa cell viadiffusionora pump(e.g.,
whenthe moleculesare toobig),cellscanengulf the moleculesorparticleswiththeirplasma
membrane ina processcalledendocytosis.Similarly,moleculescanbe movedoutof a cell via
exocytosis.Inbothprocesses,the plasmamembrane movestosurroundthe moleculesor
particlesandformsa little vesicle thatispinchedoff inside the cell (endocytosis) orfuseswith
the plasmamembrane anddumpsitscontentsoutside the cell (exocytosis).
4 Cells are connected and communicate with each other.
3.12 Connectionsbetweencellsholdtheminplace andenable themtocommunicate witheach
other.
TAKE-HOME MESSAGE 3.12: In multicellularorganisms,mostcellsare connectedtoothercells.
The connectionscanform a water-tightseal betweenthe cells(tight junctions),canholdsheets
of cellstogetherwhile allowingfluidtopassbetweenthe cell (desmosomes),orcanfunctionlike
secretpassageways,allowingthe movementof cytoplasm, molecules,andothersignals
betweencells(gapjunctions).
5 Nine important landmarks distinguish eukaryotic cells.
3.13 The nucleusisthe cell’sgeneticcontrol center.
TAKE-HOME MESSAGE 3.13: The nucleusisusuallythe largestandmostprominentorganellein
the eukaryoticcell.Itdirectsmostcellularactivitiesbycontrollingwhichmoleculesare produced
and inwhat quantity.The nucleusisalsothe storehouseforall hereditaryinformation.
3.14 Cytoplasmandthe cytoskeletonformthe cell’sinternal environment,provide its
physical support,andcan generate movement.
TAKE-HOME MESSAGE 3.14: The innerscaffoldingof the cell,whichismade fromproteins,is
the cytoskeleton.Consistingof three typesof proteinfibers—microtubules,intermediate
filaments,andmicrofilaments—the cytoskeletongivesanimal cellstheirshape andsupport,
givescellssome abilitytocontrol theirmovement,andservesasaseriesof tracks onwhich
organellesandmoleculesare guidedacrossandaroundthe inside of the cell.
3.15 Mitochondriaare the cell’senergyconverters.

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TAKE-HOME MESSAGE 3.15: In mitochondria,whichare foundinnearlyall eukaryoticcells,the
energycontainedinthe chemical bondsof carbohydrate,fat,andproteinmoleculesis
convertedintocarbondioxide,water,andATP,the energysource forall cellularfunctionsand
activities.Mitochondriamayhave theirevolutionaryoriginsassymbioticbacterialivinginside
othercells.
3.16 Lysosomesare the cell’sgarbage disposals.
TAKE-HOME MESSAGE 3.16: Lysosomesare round,membrane-enclosed,acid-filledorganelles
that functionas a cell’sgarbage disposals.Theyare filledwithabout50 differentdigestive
enzymesandenable acell todismantle macromolecules,includingdisease-causingbacteria.
3.17 The endoplasmicreticulumisthe site where cellsbuildproteinsanddisarmtoxins.
TAKE-HOME MESSAGE 3.17: The productionandmodificationof biological moleculesin
eukaryoticcellsoccursina systemof organellescalledthe endomembrane system, which
includes,amongotherorganelles,the roughandsmoothendoplasmicreticulum.InroughER,
proteinsthatwill be shippedelsewhere inthe bodyare foldedandpackaged.Inthe smoothER,
lipidsare synthesizedandalcohol,antibiotics,andotherdrugsare detoxified.
3.18 The Golgi apparatus isthe site where the cell processesproductsfordelivery
throughoutthe body.
TAKE-HOME MESSAGE 3.18: The Golgi apparatus—anotherorganellewithinthe
endomembranesystem—processesmoleculessynthesizedinacell andpackagesthose thatare
destinedforuse elsewhere inthe body.
3.19 The cell wall providesadditionalprotectionandsupportforthe plantcells.
TAKE-HOME MESSAGE 3.19: The cell wall isan organelle foundinplants(andinsome other
non-animal organisms).Itismade primarilyfromthe carbohydrate celluloseanditsurrounds
the plasmamembrane of the cell.The cell wall conferstremendousstructural strengthonplant
cells,givesplantsincreasedresistance towaterloss,andprovidessomeprotectionfrominsects
and otheranimalsthatmighteat them.Inplants,plasmodesmata connectcellsand enable
communicationandtransportbetweenthem.
3.20 Vacuolesare multipurpose storage sacsforcells.
TAKE-HOME MESSAGE 3.20: In plants,vacuolescanoccupymost of the interiorspace of the
cell.Vacuolesare alsopresentinsome othereukaryoticspecies.Theyfunctionasstorage spaces
and playa role innutrition,waste management,predatordeterrence,reproduction,and
physical support.
3.21 Chloroplastsare the plantcell’spowerplant.
TAKE-HOME MESSAGE 3.21: The chloroplastisthe organelle inplantsandalgae thatisthe site
of photosynthesis—the conversionof lightenergyintochemical energy,withoxygenasaby-
product.Chloroplastsmayhave originallybeenbacteriathatwere engulfedbyapredatorycell
by endosymbiosis.

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