BIOLOGYBIOLOGY

THE STUDY OF LIFETHE STUDY OF LIFE

Eight Characteristics of LifeEight Characteristics of Life

• HHomeostasisomeostasis

• EEnergy Usenergy Use

• RReproductioneproduction

• CCellsells

• AAdaptationsdaptations

• RResponse to Stimuliesponse to Stimuli

• GGrowth & Developmentrowth & Development

• OOrganizedrganized

Pneumonic Device:

Great Aunt Rose Only Ever Cooks Rare Hamburgers

Organisms:Organisms:• Organisms must Organisms must

possess possess all eightall eight characteristics in characteristics in order to be order to be considered considered alivealive

• An organism is An organism is something that is something that is currently livingcurrently living

• Ranges from: Ranges from: Bacteria (20 nm) to Bacteria (20 nm) to Armillaria ostoyaeArmillaria ostoyae (10 (10 km)km)

To

Growth & DevelopmentGrowth & Development

• Two ways growth occurs in multicellular organisms:Two ways growth occurs in multicellular organisms:– Cell enlargement – each cell gets bigger (exp: muscle Cell enlargement – each cell gets bigger (exp: muscle

and fat cells)and fat cells)

– Cell division (reproduction)- cells reproduce producing Cell division (reproduction)- cells reproduce producing more cells more cells

• Two processes of development:Two processes of development:

1.1. Cell DivisionCell Division 2. Differentiation – Each cell becomes specialized to 2. Differentiation – Each cell becomes specialized to perform a perform a certain task (Stem cells- can become certain task (Stem cells- can become nerve cells; muscle cells; skin cells; etc.) nerve cells; muscle cells; skin cells; etc.)

AdaptationsAdaptations

• AdaptationsAdaptations – changes made by an – changes made by an organism in response to the environment organism in response to the environment in order to survive.in order to survive.ExamplesExamples::

Evolutionary ProcessEvolutionary Process

• Evolution-Evolution- the process by which an the process by which an entire species adaptsentire species adapts (in behavior(in behavior

and/or physical characteristics) to the environment and/or physical characteristics) to the environment 1.1. There will be There will be variationsvariations amongst a species: amongst a species:

• MutationsMutations – genetic differences within a species – genetic differences within a species• Mutations may cause an “Mutations may cause an “adaptive advantage”adaptive advantage”• Examples:Examples:

• Within a population there is Within a population there is constant struggleconstant struggle and and competition for resources and survival. competition for resources and survival.

• How may adaptive advantages help an individual?How may adaptive advantages help an individual?• Individuals within a population that have Individuals within a population that have adaptive adaptive

advantagesadvantages survive longer:survive longer:

1.1. Will tend to reproduce more offspringWill tend to reproduce more offspring2.2. Mutation will shift over time into a common Mutation will shift over time into a common traittrait3.3. This process will continue with new mutationsThis process will continue with new mutations

Examples of EvolutionExamples of Evolution

Adaptive Advantage – Giraffes Neck Anyone want to explain the process?

Instinctive Migration- change in behavior

HomeostasisHomeostasis

• Homeostasis- Homeostasis- Stable internal conditionStable internal condition

• Examples of homeostatic Examples of homeostatic mechanisms:mechanisms:

•Heart rateHeart rate

• Body temperatureBody temperature

• ph levelsph levels

• water levels water levels

•Others: Others:

Responding to stimuliResponding to stimuli

• Organisms respond to Organisms respond to a stimuli in order to a stimuli in order to maintain homeostasismaintain homeostasis

• SensesSenses: Making : Making observations which observations which lead to responses lead to responses

• ReflexesReflexes: : Unconscious Unconscious responses to stimuli responses to stimuli

• BlinkingBlinking• •

Responding to stimuliResponding to stimuli

• BehaviorsBehaviors: Learned : Learned and instinctive and instinctive responses to responses to stimuli stimuli – MigrationMigration– HibernationHibernation– Putting a coat on when Putting a coat on when

it is coldit is cold– –

OrganizedOrganized

Molecules

Cell Parts

Cells

Tissues

Organs

Organ system

Organism

Cellular Level – All organisms are at least organized to this level

Energy UseEnergy Use

• AutotrophicAutotrophic– Organisms make their Organisms make their

own food own food that they will that they will then convert to energythen convert to energy

– Examples:Examples:– Photosynthesis: Photosynthesis:

***Carbon dioxide and ***Carbon dioxide and water are water are changed into food changed into food and oxygenand oxygen

• Heterotrophic Heterotrophic – Organisms must take in Organisms must take in

food from an outside food from an outside sourcesource

– ExamplesExamples

Process:Process:• Ingestion or absorptionIngestion or absorption• DigestionDigestion• TransportTransport• Cell RespirationCell Respiration• Excretion Excretion

Organisms obtain energy by one of two methods:

CellsCells

• Cells – basic units of structure and function for all Cells – basic units of structure and function for all living thingsliving things

• All organisms are made of one or moreAll organisms are made of one or more• Three Types of Cells: Plant, Animal, Prokaryotic Three Types of Cells: Plant, Animal, Prokaryotic

(lack a nucleus)(lack a nucleus)

Unicellular vs MulticellularUnicellular vs Multicellular

• UnicellularUnicellular - Composed of - Composed of just one celljust one cell. Must carry . Must carry out all of life's functions. out all of life's functions. 

• Multicellular- Multicellular- CConsist of onsist of more than one cell. more than one cell. HHave differentiated cells that perform specialized ave differentiated cells that perform specialized functions. Individual cells cannot survive on their functions. Individual cells cannot survive on their own.own.

ReproductionReproduction

• AsexualAsexual– One parentOne parent– Each organism is Each organism is

genetically identicalgenetically identical– “ “Fast and easy”Fast and easy”– Budding & fissionBudding & fission

• SexualSexual– Requires two Requires two

parents parents – Organisms Organisms

genetically differentgenetically different– “ “Slow and hard”Slow and hard”– Sex cells from each Sex cells from each

gender joingender join

•Reproduction- process by which organisms produce Reproduction- process by which organisms produce offspringoffspring