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Study ofStudy of

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CharacteristicCharacteristics of Lifes of Life

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What is Biology?What is Biology?

BiologyBiology is the study is the study of all living thingsof all living things

Living things are Living things are called called organismsorganismsOrganisms include Organisms include bacteria, protists, bacteria, protists, fungi, plants, & fungi, plants, & animalsanimals

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All Living Things Share All Living Things Share Common Common

CharacteristicsCharacteristics1.1. Basic Unit is the Basic Unit is the

CellCell

2.2. They They ReproduceReproduce

3.3. All Based On All Based On Universal Genetic Universal Genetic Code Code (DNA)(DNA)

4.4. Grow & DevelopGrow & Develop

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Common Common CharacteristicsCharacteristics

5.5. Obtain & Use Materials & Obtain & Use Materials & EnergyEnergy

6.6. RespondRespond To Their To Their EnvironmentEnvironment

7.7. Maintain A Maintain A Stable Internal Stable Internal EnvironmentEnvironment

8.8. AS A GROUPAS A GROUP, Living Things , Living Things EvolveEvolve, That Is They Change , That Is They Change Over TimeOver Time

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Characteristics of Characteristics of OrganismsOrganisms

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All Organisms are All Organisms are made of Cellsmade of Cells

Cell Structure and Cell Structure and FunctionFunction

CellCell basic unit of life basic unit of life

All organisms are All organisms are made of and develop made of and develop from cellsfrom cells

Some composed of Some composed of only a single cell only a single cell (unicellular) (unicellular) which is which is usuallyusually identical to identical to parentparent

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Facts About CellsFacts About CellsCells are the Cells are the smallest living smallest living unitunit of an organism of an organism

All cells contain All cells contain cytoplasmcytoplasm

All cells are surrounded by a All cells are surrounded by a cell membranecell membrane that controls that controls what enters & leaves the cellwhat enters & leaves the cell

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More Cell FactsMore Cell FactsCells are complex & Cells are complex & highly highly organizedorganized

Cells have parts Cells have parts called called organellesorganelles that that do different jobsdo different jobs

e.g. Chloroplasts in e.g. Chloroplasts in plants make sugarsplants make sugars

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More Cell FactsMore Cell FactsThe simplest cells The simplest cells are called are called ProkaryotesProkaryotes

These cells These cells DO NOT DO NOT have a nucleus or have a nucleus or membrane-bound membrane-bound organellesorganelles

BacteriaBacteria are are examplesexamples

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More Cell FactsMore Cell FactsMore complex cells More complex cells are called are called EukaryotesEukaryotes

These cells These cells DO have DO have a nucleus and a nucleus and membrane-bound membrane-bound organellesorganelles

Plants, animals, Plants, animals, protists, & fungiprotists, & fungi are are examplesexamples

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Organisms are Grouped by Organisms are Grouped by their Number of Cellstheir Number of Cells

Unicellular OrganismsUnicellular Organisms– Living Organism Made Up Of Living Organism Made Up Of

One CellOne Cell

Multicellular OrganismsMulticellular Organisms– Living Organism Made Up Of Living Organism Made Up Of

Many, Specialized CellsMany, Specialized Cells

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CellsCellsAll living things are All living things are composed of composed of cellscellsIn multicellular In multicellular organisms, many are organisms, many are specializedspecialized to perform to perform specific functionsspecific functionsCells are always very Cells are always very smallsmallThe size of multi-celled The size of multi-celled organisms depends on organisms depends on the number of cells the number of cells NOT their sizeNOT their size

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Living things reproduceLiving things reproduce

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Organisms Reproduce Organisms Reproduce to Pass on their to Pass on their Genetic TraitsGenetic Traits

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ReproductionReproduction

All species have the All species have the ability to reproduceability to reproduceNot essential to survival of individual Not essential to survival of individual but but

is essential for continuation of a speciesis essential for continuation of a species

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Two Types of Two Types of ReproductionReproduction

Sexual Sexual ReproductionReproduction

Involves 2 parentsInvolves 2 parents

Egg fertilized by Egg fertilized by sperm to make a sperm to make a ZYGOTEZYGOTE

Offspring Offspring DIFFERENT from DIFFERENT from parentsparents

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Two Types of Two Types of ReproductionReproduction

Asexual Asexual ReproductionReproductionInvolves a single Involves a single organism or cellorganism or cell

Cell dividesCell divides

Offspring Offspring IDENTICAL to IDENTICAL to parentparent

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Cells Have a Genetic Cells Have a Genetic CodeCode

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Genetic CodeGenetic Code

DNADNA ( (deoxyribose nucleic deoxyribose nucleic acidacid) carries the genetic ) carries the genetic code for all organismscode for all organisms

All organismsAll organisms contain DNA contain DNA

DNA DNA codes for the proteinscodes for the proteins that make up cells & do all that make up cells & do all the work necessary for lifethe work necessary for life

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Organisms Grow & Organisms Grow & DevelopDevelop

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Growth & DevelopmentGrowth & Development

Organisms Organisms growgrow by by producing MORE producing MORE CELLS & by cell CELLS & by cell ENLARGEMENTENLARGEMENT

Organisms Organisms developdevelop as they mature into as they mature into an adult organisman adult organism

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GrowthGrowth

Grow occurs as the result of Grow occurs as the result of cell cell division and cell enlargementdivision and cell enlargement

Cell division Cell division is the formation of is the formation of two cells from a two cells from a preexisting cellpreexisting cell

New cells enlarge as they matureNew cells enlarge as they mature

When a cell grows to a size where When a cell grows to a size where its its surface area isnsurface area isn’’t big enough t big enough for its volumefor its volume, the cell divides, the cell divides

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Cells Require Food & Cells Require Food & EnergyEnergy

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Food RequirementsFood RequirementsAutotrophsAutotrophs can make can make their own foodtheir own food

Photoautotrophs Photoautotrophs use use sunlight to make sunlight to make food (photosynthesis)food (photosynthesis)

Chemoautotrophs Chemoautotrophs use chemicals such use chemicals such as iron & sulfur as as iron & sulfur as their energytheir energy

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Food RequirementsFood Requirements

HeterotrophsHeterotrophs can NOT make can NOT make their own foodtheir own food

They must consume other They must consume other organismsorganisms

HerbivoresHerbivores eat plants eat plants

CarnivoresCarnivores eat meat eat meat

OmnivoresOmnivores eat plants & animals eat plants & animals

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All organisms need All organisms need substances such as substances such as nutrients, water, and gasesnutrients, water, and gases from the environmentfrom the environment

The The stability of the stability of the environmentenvironment depends on the depends on the healthy functioning of healthy functioning of organisms in that organisms in that environmentenvironment

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MetabolismMetabolism

Sum of all the chemical Sum of all the chemical reactions in an organismreactions in an organism

All All require energyrequire energy

SunlightSunlight is the ultimate is the ultimate energy for life on Earth energy for life on Earth

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MetabolismMetabolism

Cellular RespirationCellular Respiration – Cells releasing the chemical Cells releasing the chemical

energy stored in foodsenergy stored in foods

6O6O22 + C + C66HH1212OO66 6CO 6CO22 + + 6H6H22OO

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Organisms Respond to Organisms Respond to StimuliStimuli

Organisms Organisms RespondRespond to to stimulistimuli (Temperature, Water, Food (Temperature, Water, Food Supplies, etc.) Supplies, etc.) In Order To In Order To Survive & ReproduceSurvive & Reproduce

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HomeostasisHomeostasis

Keeping The Internal Environment Keeping The Internal Environment (Homeostasis)(Homeostasis) Of The Cell or Of The Cell or Organism Within The Ranges Organism Within The Ranges Required For LifeRequired For LifeStable internal conditions of Stable internal conditions of pH, pH, temperature, water balance, etctemperature, water balance, etc..

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Living Things EvolveLiving Things Evolve

Groups Of Groups Of OrganismsOrganisms (Not (Not Individuals) Change Individuals) Change Over Time In Order Over Time In Order To Survive Within To Survive Within Changing Changing Environments.Environments.Fossil recordsFossil records show show changes in groups changes in groups of organismsof organisms

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Explains why Explains why organisms look organisms look and behaveand behave the way they do the way they do

Provides a basis for exploring Provides a basis for exploring the the relationships amongrelationships among different groups of organismsdifferent groups of organisms

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Natural SelectionNatural Selection

Natural selection is the Natural selection is the driving force in evolutiondriving force in evolution

Organisms that have Organisms that have certain certain favorable traitsfavorable traits are better able to are better able to successfully reproducesuccessfully reproduce than organisms that lack than organisms that lack these traitsthese traits

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Natural SelectionNatural Selection

Survival of organisms Survival of organisms with favorable traits with favorable traits cause a cause a gradual gradual change in change in populations over populations over many generationsmany generations

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Life is Organized on Life is Organized on Several LevelsSeveral Levels

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LevelsLevelsAtomsAtomsMoleculesMoleculesOrganellesOrganellesCellsCells – life starts here – life starts hereTissuesTissuesOrgansOrgansSystemSystemOrganismOrganism

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LevelsLevels

PopulationPopulation

CommunitCommunityy

EcosystemEcosystem

BiosphereBiosphere

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Quiz Next Time! Quiz Next Time!

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