Chapter 1Chapter 1

The Science The Science of Lifeof Life

ObjectivesObjectives

To introduce the characteristics that are To introduce the characteristics that are shared by all living organisms, including shared by all living organisms, including ourselvesourselves

How biologists use the scientific method How biologists use the scientific method to approach the study of living organismsto approach the study of living organisms

List and connect the seven unifying List and connect the seven unifying THEMES of BiologyTHEMES of Biology

History/Parts of the Microscope/Metric History/Parts of the Microscope/Metric SystemSystem

Branches of Branches of BiologyBiology

EcologyEcologyPathologyPathologyZoologyZoology

MicrobiolMicrobiologyogy

GeneticsGeneticsKinesiologKinesiologyy

What does it mean What does it mean to be alive?to be alive?

Biology is the study of LIFE, but in order Biology is the study of LIFE, but in order to fully comprehend the science, one but to fully comprehend the science, one but first define what it means to be alive?first define what it means to be alive?

Living, Non-living, or Dead? Can you Living, Non-living, or Dead? Can you differentiate?differentiate?

Life is characterized by the presence of Life is characterized by the presence of ALL seven of these properties at some ALL seven of these properties at some stage in an organism’s life.stage in an organism’s life.

1.1. Cellular organizationCellular organization

2.2. ReproductionReproduction

3.3. Metabolism Metabolism

4.4. DevelopmentDevelopment

5. Heredity5. Heredity 6. Responsiveness6. Responsiveness 7. Growth & 7. Growth &

Homeostasis Homeostasis

Unifying Themes in Unifying Themes in BiologyBiology

Theme #1 Cellular Structure & Theme #1 Cellular Structure & FunctionFunction

All living things are made of cells, All living things are made of cells, which are the smallest unit capable which are the smallest unit capable of all lifeof all life

Your body contains more than Your body contains more than 100 trillion cells 100 trillion cells (100,000,000,000,000)(100,000,000,000,000)

Hierarchy of Living Hierarchy of Living ThingsThings

Organisms

Organ Systems

Organs

Tissues

Cells

Unifying Themes Unifying Themes in Biologyin Biology

Theme #2 – ReproductionTheme #2 – Reproduction Reproduction is the process by which Reproduction is the process by which

organisms make more of their own organisms make more of their own kind from one generation to the nextkind from one generation to the next

Sexual vs. Asexual ReproductionSexual vs. Asexual Reproduction

Time frames for reproduction vary Time frames for reproduction vary among living organisms. Some among living organisms. Some bacteria produce offspring 15 minutes bacteria produce offspring 15 minutes

Unifying Themes in Unifying Themes in BiologyBiology

Theme #3- MetabolismTheme #3- Metabolism All living things use energy to move, All living things use energy to move,

grow and process information. grow and process information. Without energy, life will undoubtedly Without energy, life will undoubtedly stop.stop.

METABOLISM is the sum of all METABOLISM is the sum of all of the chemical reactions carried of the chemical reactions carried out in an organism.out in an organism.

Ultimately, almost all energy on the Ultimately, almost all energy on the planet ultimately comes from the sun.planet ultimately comes from the sun.

Autotrophs vs. HeterotrophsAutotrophs vs. Heterotrophs

Sugar, water, carbon dioxide, oxygen Sugar, water, carbon dioxide, oxygen and the sun are the key factors in the and the sun are the key factors in the processprocess

Unifying Themes in Unifying Themes in BiologyBiology

Theme #4 HomeostasisTheme #4 Homeostasis All living things must maintain a stable All living things must maintain a stable

internal environment in order to function internal environment in order to function properly ( the normal properly ( the normal body temperature body temperature for a person is ~98.6 degrees F.) for a person is ~98.6 degrees F.)

The maintenance of stable internal The maintenance of stable internal conditions, despite changesin an conditions, despite changesin an external environment is called external environment is called HOMEOSTASISHOMEOSTASIS

Organisms must respond to external Organisms must respond to external changes and adjust their internal changes and adjust their internal environment accordingly.environment accordingly.

Unifying Themes in Unifying Themes in BiologyBiology

Theme #5- HeredityTheme #5- Heredity All living things pass on traits to All living things pass on traits to

their offspring through genes that their offspring through genes that are passed from one generation to are passed from one generation to the nextthe next

The GENE is the basic unit of The GENE is the basic unit of heredity which can be found in a heredity which can be found in a molecule called Deoxyribonucleic molecule called Deoxyribonucleic Acid aka DNA. Acid aka DNA.

DNA can often become damaged DNA can often become damaged resulting in a mutation.resulting in a mutation.

more about heredity & DNA in more about heredity & DNA in chapters 9 & 10…chapters 9 & 10…

Unifying Themes in Unifying Themes in BiologyBiology

Theme #6- EvolutionTheme #6- Evolution The diversity of our living world is the The diversity of our living world is the

result of a long history of change. result of a long history of change. Change over time is essentially referred Change over time is essentially referred

to as EVOLUTION.to as EVOLUTION. Species, groups of genetically similar Species, groups of genetically similar

organisms that can produce fertile organisms that can produce fertile offspring, have also changed over time.offspring, have also changed over time.

Species with favorable traits are Species with favorable traits are more likely to survive and reproduce more likely to survive and reproduce a process known as NATURAL a process known as NATURAL SELECTION. - more about Darwin SELECTION. - more about Darwin & Natural Selection in chapter 15& Natural Selection in chapter 15

Unifying Themes in Unifying Themes in BiologyBiology

Theme #7- InterdependenceTheme #7- Interdependence This is concept that organisms in a This is concept that organisms in a

biological community live and biological community live and interact with other organisms.interact with other organisms.

Ecology is the branch of biology that Ecology is the branch of biology that studies the interactions of organisms studies the interactions of organisms with one another and also the with one another and also the

nonliving part of their environmentnonliving part of their environment..

The HistoryThe History Hans and Zacharias Janssen of Hans and Zacharias Janssen of

Holland in the 1590’s created the Holland in the 1590’s created the “first” compound microscope“first” compound microscope

Anthony van Leeuwenhoek and Anthony van Leeuwenhoek and Robert Hooke made improvements Robert Hooke made improvements by working on the lensesby working on the lenses

Anthony van Leeuwenhoek1632-1723

Robert Hooke 1635-1703

Hooke Microscope

How a Microscope WorksHow a Microscope Works

Convex Lenses arecurved glass used to make microscopes(and glasses etc.)

Convex Lenses bendlight and focus it inone spot.

How a Microscope WorksHow a Microscope Works

Ocular Lens(Magnifies Image)

Objective Lens(Gathers Light, Magnifies And Focuses Image Inside Body Tube)Body Tube

(Image Focuses)

•Bending Light: The objective (bottom) convex lens magnifies and focuses (bends) the image inside the body tube and the ocular convex (top) lens of a microscope magnifies it (again).

Body Tube

Nose Piece

ObjectiveLenses

Stage Clips

Diaphragm

Light Source

Ocular Lens

Arm

Stage

Coarse Adj.

Fine Adjustment

Base

Body TubeBody Tube

The body tube holds the objective The body tube holds the objective lenses and the ocular lens at the lenses and the ocular lens at the proper distanceproper distance

DiaphragmDiaphragm

The Diaphragm controls the amount The Diaphragm controls the amount of light on the slide/specimenof light on the slide/specimen

Turn to let more light in or tomake dimmer.

Diagram

Stage ClipsStage Clips

These 2 clips hold the These 2 clips hold the slide/specimen in place on the stage.slide/specimen in place on the stage.

Diagram

Objective LensesObjective Lenses

The Objective Lenses increase The Objective Lenses increase magnification (usually from 10x to magnification (usually from 10x to 40x)40x)

Diagram

Light SourceLight Source

Projects light upwards through the Projects light upwards through the diaphragm, the specimen and the diaphragm, the specimen and the lenseslenses

Some have lights, others have Some have lights, others have mirrors where you must move the mirrors where you must move the mirror to reflect lightmirror to reflect light

Diagram

Ocular Lens/EyepieceOcular Lens/Eyepiece

Magnifies the specimen imageMagnifies the specimen image

Diagram

ArmArm

Used to support the microscope Used to support the microscope when carried. Holds the body tube, when carried. Holds the body tube, nose piece and objective lensesnose piece and objective lenses

Diagram

StageStage

Supports the slide/specimen Supports the slide/specimen

Diagram

Coarse Adjustment KnobCoarse Adjustment Knob

Moves the stage up and down Moves the stage up and down (quickly) for focusing your image(quickly) for focusing your image

Diagram

Fine Adjustment KnobFine Adjustment Knob

This knob moves the stage This knob moves the stage SLIGHTLY to sharpen the imageSLIGHTLY to sharpen the image

Diagram

BaseBase

Supports the microscopeSupports the microscope

Diagram

MagnificationMagnification

To determine your magnification…To determine your magnification…you just multiply the ocular lens by you just multiply the ocular lens by the objective lensthe objective lens

Ocular 10x Objective 40x:10 x 40 = Ocular 10x Objective 40x:10 x 40 = 400400

Objective Lens have their magnificationwritten on them.

Ocular lenses usually magnifies by 10x

So the object is 400 times “larger”

Using a MicroscopeUsing a Microscope

Start on the lowest magnificationStart on the lowest magnification Don’t use the coarse adjustment Don’t use the coarse adjustment

knob on high magnification…you’ll knob on high magnification…you’ll break the slide!!!break the slide!!!

Place slide on stage and lock clipsPlace slide on stage and lock clips Adjust light source (if it’s a mirror…Adjust light source (if it’s a mirror…

don’t stand in front of it!)don’t stand in front of it!) Use fine adjustment to focusUse fine adjustment to focus

Nose PieceNose Piece

The Nose Piece holds the objective The Nose Piece holds the objective lenses and can be turned to increase lenses and can be turned to increase the magnificationthe magnification