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

have have 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

HomeostasisHomeostasis

• Homeostasis- Homeostasis- Stable internal conditionStable internal condition• Examples:Examples:

•Heart rateHeart rate• Body temperatureBody temperature• ph levelsph levels• water levels water levels •Others: Others:

• Organisms must be able to maintain Organisms must be able to maintain homeostasis in order to survivehomeostasis in order to survive

Energy UseEnergy Use

• AutotrophicAutotrophic– Organisms that make Organisms that make

their own food their own food that they that they will then convert to will then convert to energyenergy

– Examples:Examples:– Photosynthesis: Photosynthesis:

• Heterotrophic Heterotrophic – Organisms that Organisms that

must take in food must take in food from an outside from an outside sourcesource

– ExamplesExamples

Organisms obtain energy by one of two methods:

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– –

CellsCells

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

• All organisms are made of one or moreAll organisms are made of one or more

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.

AdaptationsAdaptations

• In order for an organism to survive it must be able to In order for an organism to survive it must be able to adapt in response to the environment it is in.adapt in response to the environment it is in.

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

• Evolution: change within a population of a certain Evolution: change within a population of a certain species of organisms over a long period of timespecies of organisms over a long period of time

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

Growth & DevelopmentGrowth & Development

• Two ways an organism can grow in a multicellular Two ways an organism can grow in a multicellular organism:organism:– 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

• Development: Occurs when an organism, cells, or Development: Occurs when an organism, cells, or

body tissues gain the ability to perform a certain body tissues gain the ability to perform a certain tasktask – Occurs by:Occurs by:

• Cell DivisionCell Division• Cell Specialization: Each cell becomes different to perform Cell Specialization: Each cell becomes different to perform

its taskits task

OrganizedOrganized

Molecules

Cell Parts

Cells

Tissues

Organs

Organ system

Organism

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