Unit 1Unit 1The Nature of ScienceThe Nature of Science

I. I. ScienceScience is an organized is an organized way of using evidence to way of using evidence to learn about the natural learn about the natural

world.world.A.A. The goals of science:The goals of science:

1.1. Investigate and understand Investigate and understand naturenature

2.2. Explain events in natureExplain events in nature

3.3. Use information to make Use information to make useful predictionsuseful predictions

B. B. Scientific EvidenceScientific Evidence is based is based on on DataData..DataData = gathered information = gathered information

1. Quantitative: 1. Quantitative: Observations involving Observations involving measurementmeasurement..ex: the ant has 6 legsex: the ant has 6 legs

2. Qualitative: Observations 2. Qualitative: Observations that that cannot be easily measuredcannot be easily measured..ex: the insect has dark spotsex: the insect has dark spots

C. C. Interpreting & Explaining Interpreting & Explaining DataData

1. 1. InferenceInference: An interpretation : An interpretation based on based on experienceexperience and and prior prior knowledge.knowledge.

2. 2. HypothesisHypothesis: Possible : Possible explanation for a set of explanation for a set of observations or an answer to a observations or an answer to a scientific question.scientific question.

A Hypothesis is:A Hypothesis is:

Useful only if it can be Useful only if it can be testedtested..Based on prior knowledge, Based on prior knowledge,

inferences, or a inferences, or a guessguess..Usually tested through Usually tested through

controlled experimentscontrolled experimentsUseful whether Useful whether right or wrongright or wrong

D. How Science WorksD. How Science Works

1.1. ProblemProblem: Ask a: Ask a question you question you want answered.want answered.

2.2. HypothesisHypothesis: Possible : Possible explanation for an observed set explanation for an observed set of facts.of facts.

3.3. Controlled ExperimentControlled Experiment: An : An experiment where two variables experiment where two variables are tested and compared.are tested and compared.

D. How Science WorksD. How Science Works

VariableVariable: A factor in an : A factor in an experiment that changes.experiment that changes.

ex: Temperature, Time, ex: Temperature, Time, Light Light intensity, etc…intensity, etc…

In a controlled experiment, In a controlled experiment, only one variable is changed only one variable is changed at a timeat a time..

D. How Science WorksD. How Science WorksDependent VariableDependent Variable: Factor in : Factor in

an experiment that is an experiment that is observed. It may change due observed. It may change due to the independent variable.to the independent variable.

Independent VariableIndependent Variable: Factor : Factor in an experiment that a in an experiment that a scientist purposely changes.scientist purposely changes.

D. How Science WorksD. How Science Works

4. Record and 4. Record and AnalyzeAnalyze results: results: Carefully and accurately record Carefully and accurately record quantitative and qualitative quantitative and qualitative observations, including observations, including graphs, graphs, tables, and illustrations.tables, and illustrations.

5. Draw a 5. Draw a ConclusionConclusion: Does the : Does the data support or refute your data support or refute your hypothesis?hypothesis?

For a scientific experiment to be For a scientific experiment to be valid, it must be valid, it must be repeated.repeated.

TheoryTheoryA well tested explanation that A well tested explanation that

unifies a broad range of unifies a broad range of observations. It is not observations. It is not absolute truth!absolute truth!

ex: Evolution; The Big Bangex: Evolution; The Big Bang

II. What is BiologyII. What is Biology

The study of life and The study of life and living thingsliving things

Bio = Life Bio = Life - ology = The study of- ology = The study of

What constitutes life?What constitutes life?

A. Living things share the A. Living things share the following characteristics:following characteristics:1.1.Living things are Living things are made of made of

cells.cells.UnicellularUnicellular – Made of one – Made of one

cellcellMulticellularMulticellular – Made of many – Made of many

cellscells

2. Living things 2. Living things ReproduceReproduce..Sexual ReproductionSexual Reproduction – 2 cells – 2 cells

from 2 parents unite to produce from 2 parents unite to produce a new a new

organism.organism.Asexual ReproductionAsexual Reproduction – –

Single parent.Single parent.

~Necessary for the survival of a ~Necessary for the survival of a speciesspecies, but not for an , but not for an individualindividual..

3. Living things 3. Living things are based on a are based on a universal universal genetic codegenetic code..

The molecule of The molecule of inheritance is inheritance is called called DNADNA..

4. Living things need 4. Living things need materials and energymaterials and energy

Nutrition:Nutrition: Obtaining Obtaining materials from materials from the the environment to environment to be used for life be used for life functions.functions.

What is What is MetabolismMetabolism??

The sum total of all life The sum total of all life functions and chemical functions and chemical reactions of an organism reactions of an organism that keep it alive. that keep it alive.

3 Methods of 3 Methods of NutritionNutrition

a. a. AutotrophicAutotrophic – Convert light and – Convert light and inorganic molecules into useful inorganic molecules into useful energy (photosynthesis)energy (photosynthesis)

Ex: Plants, some bacteria and Ex: Plants, some bacteria and protists.protists.

3 Methods of 3 Methods of NutritionNutrition

b. b. HeterotrophicHeterotrophic – obtain – obtain energy by eating energy by eating plants, animals, etc…plants, animals, etc…

Ex: animals, fungi, Ex: animals, fungi, bacteria and protistsbacteria and protists

3 Methods of 3 Methods of NutritionNutrition

c. c. DecomposersDecomposers: obtain : obtain energy by consuming energy by consuming remains of organisms remains of organisms that have died.that have died.

Ex: fungi, bacteriaEx: fungi, bacteria

NutritionNutritioni. i. IngestionIngestion – Taking in food – Taking in food

ii. ii. DigestionDigestion – breaking – breaking down down food into usable food into usable partsparts

iii. iii. EgestionEgestion – Riding the – Riding the body body of solid wasteof solid waste

5. Growth: Living 5. Growth: Living things things grow & developgrow & developIncrease in Increase in size and/or size and/or numbernumber of of cells of an cells of an organism.organism.

6. Regulation6. RegulationLiving things Living things respond to their respond to their environment.environment.

Regulation: Regulation: ControlControl and and coordinationcoordination of of all life functions all life functions in order to in order to maintain maintain homeostasishomeostasis..

What is What is HomeostasisHomeostasis??

The maintenance of a The maintenance of a stable internal stable internal environmentenvironment..

Ex: fight or flight Ex: fight or flight responseresponse

7. Excretion7. ExcretionLiving things remove cellular wastes such as water and CO2

8. Synthesis – 8. Synthesis – putting putting togethertogether

Living things can Living things can synthesizesynthesize new new products from products from the chemical the chemical reactions reactions occurring in occurring in body cells.body cells.

9. Transport9. TransportLiving things can Living things can transporttransport the the synthesized synthesized materials materials throughout throughout their body.their body.

Absorption & Absorption & CirculationCirculation

RespirationRespirationProcess by Process by which which energyenergy is is obtained obtained fromfrom the the breakdown breakdown ofof foodfood and and used for life used for life activities.activities.

B. The 8 Life FunctionsB. The 8 Life FunctionsProcesses that are Processes that are required by a living required by a living organism to sustain life.organism to sustain life.

The 8 life functions are:The 8 life functions are:Nutrition, transport, Nutrition, transport, respiration, excretion, respiration, excretion, synthesis, regulation, synthesis, regulation, growth, and reproductiongrowth, and reproduction

IIIa. The Biology IIIa. The Biology LaboratoryLaboratory

A.A. Lab Safety: read pages Lab Safety: read pages 1060-1062 in your 1060-1062 in your textbook.textbook.

B.B. Measuring – The metric Measuring – The metric system (pg. 1063 & pg. system (pg. 1063 & pg. 24)24)

The Metric SystemThe Metric System1.1. Fill in the proper units Fill in the proper units

and measurements.and measurements._________: measures _________: measures

lengthlength1km = _________ meters1km = _________ meters

1meter = _______cm1meter = _______cm 1cm = ______mm1cm = ______mm 1 inch = _______cm1 inch = _______cm

Meter 1000

100102.54

The Metric SystemThe Metric System

_________: measures _________: measures volumevolume

1 liter = ________ mL1 liter = ________ mL

1L = ________ quartz1L = ________ quartz

Liter

10001.0

6

The Metric SystemThe Metric System

________: measure mass________: measure mass

1kg = _______ grams1kg = _______ grams

1g = ______ mg1g = ______ mg

1kg = ______ lbs1kg = ______ lbs

Grams 1000

10002.20

The Metric SystemThe Metric System________: measures ________: measures temperaturetemperature

____C = water freezes____C = water freezes

____C = water boils____C = water boils

____C = human body ____C = human body temperaturetemperature

Celsius

0°100

°37°

2. Practice 2. Practice Conversions:Conversions:

Try the conversions Try the conversions on pg. 5 on your own!on pg. 5 on your own!

IIIb. Illustrations & IIIb. Illustrations & DiagramsDiagrams

A.A. AnatomicAnatomical Terms al Terms for for DirectionDirection

1.Anterior – front

2.Posterior – back

3.Proximal – close to

4.Distal – distant from

5.Dorsal – back

6.Ventral – stomach side

7. Superior – higher/above

8. Inferior – lower/below

9. Medial – towards the center

10. Lateral – away from the center

IV. ClassificationIV. Classification

To study the diversity of life, biologists To study the diversity of life, biologists use a classification system to name use a classification system to name organisms and group them in a logical organisms and group them in a logical manner.manner.

A. A. TaxonomyTaxonomy: : The study and naming of The study and naming of the diversity of life.the diversity of life.

1. 1. Binomial NomenclatureBinomial Nomenclature: : Two name Two name naming systemnaming systemCarolus LinneausCarolus Linneaus – Scientist who – Scientist who

came up with this systemcame up with this system

Binomial NomenclatureBinomial Nomenclature

Written in Written in LatinLatin ItalicizedItalicized 11stst name is capitalized (Genus) name is capitalized (Genus) 22ndnd name is lower case (species) name is lower case (species)

EX: EX: Homo sapiensHomo sapiens

2. Levels of Classification2. Levels of Classification

3 Domains3 Domains: : Eukarya, Eukarya,

Archea,Archea, EubacteriaEubacteria

Classification Classification SystemSystem Kingdom – Kingdom – Most DiverseMost Diverse

PhylumClass

Order

Species – Least Diverse

Genus

Family

MoneraMoneraPrimitive cell Primitive cell structure; structure; lack nuclear lack nuclear membrane membrane and and membranoumembranous organelless organelles

Ex: Blue-green algae; Bacteria

ProtistaProtistaUnicellular; Unicellular; membranous membranous organelles; organelles; animal/plant animal/plant like like characteristicharacteristicscs

Ex: Paramecium; Amoeba

FungiFungiAbsorb Absorb digested digested food from food from the the environmentenvironment

Branched Branched filamentsfilaments

Ex: Yeast; Bread mold; mushroom

PlantaePlantae

Multicellular, Multicellular, photosynthetphotosynthetic organismsic organisms

Ex: moss; geranium; maple tree; corn

AnimaliaAnimalia

Multicellular Multicellular organisms organisms that ingest that ingest their foodtheir food

Ex: jellyfish; earthworm; snail; lobster; shark; eagle; crocodile; lion; human

Who doesn’t belongWho doesn’t belongVirusesViruses do not belong do not belong in any of the 5 in any of the 5 kingdoms.kingdoms.

DomainDomainContains the greatest # Contains the greatest #

of organisms.of organisms.

SpeciesSpeciesContains the organisms Contains the organisms

that are most closely that are most closely related.related.

Humans Scientific Humans Scientific NameNameK – AnimaliaK – Animalia

P – ChordataP – ChordataC – MammaliaC – MammaliaO – PrimatesO – PrimatesF – HominidaeF – HominidaeG – G – HomoHomoS - S - sapienssapiens

V. InstrumentsV. InstrumentsA. A. Compound Compound light light microscopemicroscope – – Used to Used to magnify magnify small items small items up to 1000X.up to 1000X.

1. Body Tube

2. Nose Piece

3. Scanning Power (4X)4. Low Power

(10X)5. High Power (40X)6. Stage Clips7. Diaphragm8. Light Source

9. Eye Piece(Ocular Lens) – 10X

10. Arm

11. Stage

12. Coarse Adjustment

13. Fine Adjustment

14. Base

A. Compound Light A. Compound Light MicroscopeMicroscope

2. Use the text book to 2. Use the text book to describe the main describe the main function of each function of each

microscope component.microscope component.Pg. 1064Pg. 1064

IV. Compound Light IV. Compound Light MicroscopeMicroscope

C. How is the magnification of a C. How is the magnification of a compound light microscope compound light microscope determined?determined?

Ocular lens X Objective lensOcular lens X Objective lens(10x OL) X (40X HO) = 400X(10x OL) X (40X HO) = 400XOL = Ocular lensOL = Ocular lensHO = high power objectiveHO = high power objective

3. Field of View3. Field of View

Circle of light seen through Circle of light seen through the eyepiece.the eyepiece.

As As magnification magnification increasesincreases, , field of view field of view decreasesdecreases..

Low Power ObjectiveFocus

Objective

High Power Objective

4. Resolving Power4. Resolving Power

The ability to The ability to distinguish distinguish between items between items that are close that are close together.together.

5. Depth of Focus5. Depth of Focus

The ability to distinguish the depth of The ability to distinguish the depth of the field.the field.

6. Preparing a Wet Mount

StainingStainingSometimes it is Sometimes it is

helpful to stain a helpful to stain a specimen to be specimen to be able to see its able to see its parts more clearly.parts more clearly.

Ex: The nucleus Ex: The nucleus and membrane of and membrane of a cella cell

StainsStainsBromothymol Blue Bromothymol Blue Congo Red Congo Red Lugol’s solution (Iodine)Lugol’s solution (Iodine)

7. Motion and Orientation7. Motion and Orientation

OrientationOrientation: An object appears : An object appears upside downupside down and and backwardsbackwards..

MotionMotion: When the slide is : When the slide is moved to moved to the rightthe right, the object , the object appears to moveappears to move leftleft..

When the When the slide is moved upslide is moved up, the , the object object appears to move downappears to move down..

Before

After

8. Rules8. Rules

Please read the rules at the top Please read the rules at the top of pg. 11 carefully!of pg. 11 carefully!

C. Measuring Under the C. Measuring Under the MicroscopeMicroscope

1.1. The objects under the CLM are usually The objects under the CLM are usually measured in units called measured in units called micrometers micrometers ((microns;microns;µmµm))

2.2. 1mm = 1mm = 10001000 microns microns

3.3. Practice:Practice:

1.0mm = ______µm 1700µm = ______mm1.0mm = ______µm 1700µm = ______mm

2.0mm = ______µm 2820µm = ______mm2.0mm = ______µm 2820µm = ______mm

2.5mm = ______µm 900µm = ______mm2.5mm = ______µm 900µm = ______mm

12.5mm = ______µm 82.6µm = ______mm12.5mm = ______µm 82.6µm = ______mm

1000

2000

2500

12500

1.7

2.82

0.9

.0826

4. The field of view is 2mm.

a.The diameter of the field of view in µmµm is 2000µmµm..

b.The approximate length of each structure is 400µm.µm.

D. Field of ViewD. Field of ViewThe diameter is 2.0 mm The diameter is 2.0 mm acrossacross

How many µm is each How many µm is each cell?cell?

2,000µm2,000µm = =

5 Cells5 Cells

400µm/cell

Try #5 on page 11 on Try #5 on page 11 on your own.your own.

D. Other ToolsD. Other Tools1.1. Centrifuge Centrifuge – –

A machine A machine used to used to separate separate liquids by liquids by their their densities.densities.

Ex: BloodEx: Blood

2. 2. Dissection Dissection EquipmentEquipment::

ScalpelScalpelProbeProbeForcepsForcepsScissorsScissors

3.3. Electron Electron MicroscopeMicroscope – –

Magnifies Magnifies 1000X 1000X greater than greater than a normal a normal microscope.microscope.

V. InstrumentsV. Instruments

4.4.Dissecting Dissecting microscopemicroscope – –

Used to view Used to view larger objects in larger objects in 3D.3D.

Ex: fruit fliesEx: fruit flies