[PPT]Chapter 1 The Science of Life - · Web viewTitle Chapter 1 The Science of Life Author...

transcript

Copyright Cmassengale

Warm - UpWhat are the properties of life

according to you?(These are the properties that all living

things have in common.)

HomeworkNone tonight

Biology – The Study of Biology – The Study of LifeLife

Life arose more than 3.5 billion years ago

First organisms (living things) were single celled

Only life on Earth for millions of years

Organisms changed over time (evolved)

Modified from Cmassengale

New organisms arose from older kinds

Today there are millions of species

They inhabit almost every region of Earth today

Seven Properties of LifeOrder

Use Energy(Cellular Respiration)

Growth\DevelopmentStore Information

Respond to StimulusReproductionAdaptation

Order:Order:Matter, Energy and OrganizationMatter, Energy and Organization

Living things are highly organized

An organism's/it’s structures form (or the way it is shaped) will determine its function.

Order:Order:Structure and Function of CellsStructure and Function of Cells

Cells are the basic unit of life

All organisms are made of cells and develop from one cell

Most composed of only a single cell (unicellular) which is usually identical to parent

Order:Order:CellsCells Some organisms are

composed of many cells (multicellular) Cells are different

(undergo differentiation)

Cells are small Cells are highly

organized

Cells contain specialized structures (organelles) that carry out the cell’s life processes

Many different kinds of cells exist

All cells are surrounded by a plasma membrane

Cells Contain a set of instructions called DNA (genetic information)

Order:

EnergyEnergy ALL energy comes from the SUN

(directly or indirectly) Photosynthesis is the process by

which some organisms capture the energy from the sun (solar) and transform it into energy (chemical) that can be used by living things

Energy:Energy:AutotrophsAutotrophs

Organisms that make their own food are called autotrophs

Phototrophs – use solar energy (photosynthesis) to get energy Convert H2O and CO2

into sugar and O2 Chemotrophs – use

different chemical processes to get energy

Energy:Energy:HeterotrophsHeterotrophs

Organisms that must take in food to meet their energy needs are called heterotrophsheterotrophsConsume autotrophs (herbivores), (herbivores), other heterotrophs (carnivores) (carnivores) or both (omnivores) (omnivores) for their energy needs

Complex Molecules chemicals from prey are broken down and reassembled into reassembled into molecules molecules and structures needed by organisms

Development and Growth All living things grow or get

bigger. Even single celled organisms do so after splitting.

Most organisms develop or change/mature while growing. To develop is to change your

behavior and/or structures over time

Modified from Cmassengale

Store Information:Store Information:DNADNA

Deoxyribonucleic Acid Genetic Information in all cells DNA contains instructions for

traits GENES Store the information to make

the structures and complex chemicals necessary for life PROTEINS

DNA in every body cell (SOMATIC CELLS) is exactly alike

Respond to StimulusRespond to Stimulus Respond to stimuli Respond to stimuli in

the external and internal environment

Detect and respond to changes in the environment like light, heat, sound light, heat, sound and chemical and and chemical and mechanical contactmechanical contact

Coordinates it’s responses

Respond to StimulusRespond to Stimulus(Homeostasis)(Homeostasis)

Organisms must Maintain very stable internal conditions - HOMEOSTASIS

Like temperature, water content, pH, chemical content, etc. must be maintained at specific ranges

Reproduce:Reproduce:Reproduction and Reproduction and

InheritanceInheritance All organisms produce new

organisms like themselves REPRODUCE

Organisms transmit hereditary information to their offspring INHERITANCE

Reproduce:Reproduce:Sexual ReproductionSexual Reproduction

Hereditary information from two different organisms of the same species are combined

Egg and sperm zygote (fertilized egg)

Zygote contains hereditary information from both parents

Reproduction:Reproduction:Asexual ReproductionAsexual Reproduction

Hereditary information from one, usually unicellular, organism that divides

Resulting cells contain identical hereditary information

Genetic information from single parent

Adaption:Adaption:EvolutionEvolution

Populations of organisms change (evolve) over generations (time)

Explains how many different kinds of organisms came into existence SPECIES

Explains how modern organisms are related to past organisms

Explains why organisms look and behave the way they do

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

AdaptationEvolution

Adaptation:Adaptation:Natural SelectionNatural Selection

Natural selection is the driving force in evolution Organisms that have

certain favorable traits, for a given environment, will successfully reproduce more than organisms that lack these traits

Adaptation:Adaptation:Natural SelectionNatural Selection

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

Also Called “Survival of the Fittest”

Characteristics of Life

Order (Cells) All living things are

composed of cellscells In multicellular

organisms, many are specializedspecialized to perform specific functions

Cells are always very smallsmall

The size of multi-celled organisms depends on the the number of cells NOT number of cells NOT their sizetheir size

Order Organized at both

the molecular and molecular and cellular levelscellular levels

Take in substances from the environment and organize them in complex ways

Specific cell structures (organelles) (organelles) carry out particular functions

26Copyright Cmassengale

In multicellular multicellular organisms, organisms, cells and groups of cells (tissues) are organized by their function CellsCells

tissues TissuesTissues

organs Organs Organs systemssystems SystemsSystems ORGANISMORGANISM

Use Energy Use energy in a process called

metabolismmetabolism Sum of all chemical processesSum of all chemical processes

Require energy to maintain their molecular and cellular organization, grow and reproduce

Responds to stimulus:Responds to stimulus:Example-HomeostasisExample-Homeostasis Maintain stable internal stable internal

conditionsconditions Temperature, pH, etc.Temperature, pH, etc.

Growth and Development:Growth and Development:GrowthGrowth

Grow occurs as the result of cell division and cell cell division and cell enlargementenlargement

Cell division Cell division is the formation of two cells from a preexisting preexisting cellcell

New cells enlarge as they mature

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

The process by which an adult process by which an adult organism arise organism arise is called developmentdevelopment Repeated cell divisions and cell cell

differentiationdifferentiation

Growth and Development:Growth and Development:DevelopmentDevelopment

ReproductionReproduction All species have the ability to ability to

reproducereproduce Not essential to survival of Not essential to survival of

individual individual but is essential for continuation of a species

Adaptation:Adaptation:EvolveEvolve

Ability to adapt to their environment through the process of evolutionevolution

Favorable characteristics Favorable characteristics are selected for and passed on to offspring

Called adaptationsadaptations Driven byDriven by

natural selectionnatural selectionoror “survival of the “survival of thefittest”fittest”

[PPT]Chapter 1 The Science of Life - · Web viewTitle Chapter 1 The Science of Life Author...

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