science of biology notes photo courtesy of ms. furtwangler

Science of Biology NotesScience of Biology Notes

Photo courtesy of Ms. Furtwangler

First of all, what is science?First of all, what is science?

Draw a vertical line on your paper, and Draw a vertical line on your paper, and label the two sides as “science” and “not label the two sides as “science” and “not science”science”

Brainstorm a few examples of specific Brainstorm a few examples of specific academic disciplines on each side academic disciplines on each side (besides the normal broad high school (besides the normal broad high school

classes like English, Math, Science, Social classes like English, Math, Science, Social Studies)Studies)

Take a minuteTake a minute

What is Science?What is Science? (1-1) (1-1)

The root The root sci-sci- means “to know”. Science is means “to know”. Science is one way of investigating the world in which one way of investigating the world in which we live. Science strives to: we live. Science strives to: explore and understand the natural explore and understand the natural

world,world, explain events in the natural world, and explain events in the natural world, and use those explanations to make useful use those explanations to make useful

predictions. predictions. • Are some things unpredictable?Are some things unpredictable?

Things that are not science include Things that are not science include things like…things like…

ArtArt ReligionReligion LiteratureLiterature OpinionOpinion

Is science Is science betterthanbetterthan these things? these things?

No! it is simply another way of exploring No! it is simply another way of exploring the world in which we livethe world in which we live

Science can only concern itself with Science can only concern itself with testabletestable things and\or things and\or observableobservable things things

http://www.ohsu.edu/research/rda/funding/images/scientist.jpghttp://www.isleroyalewolf.org/LMV_telemetry_1.JPG

Is scientific knowledge a set truth?Is scientific knowledge a set truth?

No!No! In our scientific explanations, we explain how In our scientific explanations, we explain how

things work using the knowledge we have to things work using the knowledge we have to explain natural phenomenaexplain natural phenomena

When our knowledge base changes, our When our knowledge base changes, our explanation may changeexplanation may change

What is Science? (1-1)What is Science? (1-1)

Scientists use Scientists use observationsobservations (process of (process of gathering information by using your five gathering information by using your five senses) to gather senses) to gather data.data.

They also use known data to make They also use known data to make inferencesinferences (a logical interpretation of the (a logical interpretation of the data based on past experiences).data based on past experiences).

Practice…Practice…

1.1. _____ There are 2 _____ There are 2 doors.doors.

2.2. _____ The people are _____ The people are fighting because fighting because someone ate their someone ate their cookies.cookies.

3.3. _____ One door is _____ One door is closed.closed.

4.4. _____ They are hitting _____ They are hitting each other hard.each other hard.

5.5. _____ Glass is broken._____ Glass is broken.

Determine in the picture if it is an observation (O) Determine in the picture if it is an observation (O) or an inference (I)or an inference (I)

O

O

O

I

I

What do scientists do?What do scientists do? BASIC SKILLS:BASIC SKILLS: 1. 1. ObservingObserving- Noting the properties of - Noting the properties of

objects and situations using the five sensesobjects and situations using the five senses 2. 2. ClassifyingClassifying- Relating objects and events - Relating objects and events

according to their properties or attributes according to their properties or attributes (Involves classifying places, objects, ideas, or (Involves classifying places, objects, ideas, or events into categories based on their events into categories based on their similarities.)similarities.)

3. 3. Space/Time RelationsSpace/Time Relations- Visualizing and - Visualizing and manipulating objects and events, dealing with manipulating objects and events, dealing with shapes, time, distance, and speedshapes, time, distance, and speed

What do scientists do?What do scientists do?

BASIC SKILLS:BASIC SKILLS: 4. 4. Using numbersUsing numbers- Using quantitative relationships, - Using quantitative relationships,

e.g. scientific notation, error, significant numbers, e.g. scientific notation, error, significant numbers, precision, ratios, and proportionsprecision, ratios, and proportions

5. 5. Measuring- Measuring- Expressing the amount of an object or Expressing the amount of an object or substance in quantitative terms, such as meters, substance in quantitative terms, such as meters, liters, grams, newtons, etc.liters, grams, newtons, etc.

6. 6. InferringInferring- Giving an explanation for a particular - Giving an explanation for a particular object or eventobject or event

7. 7. PredictingPredicting- Forecasting a future occurrence based - Forecasting a future occurrence based on past observations or the extension of dataon past observations or the extension of data

What do scientists do?What do scientists do?

INTEGRATED SKILLSINTEGRATED SKILLS 8. 8. Defining OperationallyDefining Operationally- Developing statements - Developing statements

that present a concrete description of an object or that present a concrete description of an object or event by telling one what to do or observe.event by telling one what to do or observe.

9. 9. Formulating modelsFormulating models- Constructing images, - Constructing images, objects, or mathematical formulas to explain ideasobjects, or mathematical formulas to explain ideas

10.10.Controlling variablesControlling variables- Manipulating and - Manipulating and controlling properties that relate to simulations or controlling properties that relate to simulations or events for the purpose of determining causation in events for the purpose of determining causation in experimental research designexperimental research design

What do scientists do?What do scientists do? INTEGRATED SKILLSINTEGRATED SKILLS 11. 11. Interpreting DataInterpreting Data- Arriving at explanations, - Arriving at explanations,

inferences, or hypotheses from data that have been inferences, or hypotheses from data that have been graphed or placed in a table (this frequently involves graphed or placed in a table (this frequently involves concepts such as mean, mode, median, range, concepts such as mean, mode, median, range, frequency, distribution, chi-square test, t test)frequency, distribution, chi-square test, t test)

12.12.HypothesizingHypothesizing- Stating a tentative generalization - Stating a tentative generalization of observations or inferences that may be used to of observations or inferences that may be used to explain a relatively larger number of events but that is explain a relatively larger number of events but that is subject to immediate or eventual testing by one or subject to immediate or eventual testing by one or more experiments in experimental research designmore experiments in experimental research design

13.13.ExperimentingExperimenting- Testing a hypothesis through the - Testing a hypothesis through the manipulation and control of independent variables manipulation and control of independent variables and noting the effects on a dependent variable; and noting the effects on a dependent variable; interpreting and presenting results in the form of a interpreting and presenting results in the form of a report that others can follow to replicate the report that others can follow to replicate the experiment using experimental research designexperiment using experimental research design

How Scientists WorkHow Scientists Work

““The” Scientific MethodThe” Scientific MethodScientists solve problems, but the method Scientists solve problems, but the method may vary based on the problemmay vary based on the problemThe three types of investigations:The three types of investigations:

• Experimental Research Design Experimental Research Design • CorrelationCorrelation• Descriptive InvestigationDescriptive Investigation

Steps to Experimental Scientific Steps to Experimental Scientific Investigation (The Scientific Method):Investigation (The Scientific Method):

1. Observe – 1. Observe – make an observation of make an observation of the world around you. There are two the world around you. There are two kinds of observations:kinds of observations:

Qualitative observation Qualitative observation – – descriptivedescriptive observationobservation

• Ex: The plant is a dark green.Ex: The plant is a dark green. Quantitative observation Quantitative observation – a – a numericalnumerical

observation.observation.• Ex: The flask contains 12.45 ml. There are 4 Ex: The flask contains 12.45 ml. There are 4

pennies.pennies.

Which kind of observation? Let’s Which kind of observation? Let’s practice!practice!

Determine if the statement is qualitative Determine if the statement is qualitative (A) or quantitative (B).(A) or quantitative (B).

_____ The sky is blue._____ The sky is blue. _____ There are 4 _____ There are 4

clouds.clouds. _____ There are 3 _____ There are 3

hills.hills. _____ The first hill is _____ The first hill is

small.small. _____ The clouds are _____ The clouds are

small.small. _____ There are a _____ There are a

total of 38 birds.total of 38 birds.

A

B

B

A

A

B

2. Ask a question – 2. Ask a question – based on your based on your observation, ask a question to observation, ask a question to investigate.investigate.

3. Research - 3. Research - Look in Look in booksbooks, , journalsjournals and the and the internetinternet to make additional to make additional observations and research about the observations and research about the questions you made from your questions you made from your observation.observation.

4. Formulate a hypothesis4. Formulate a hypothesis: - Propose : - Propose a a scientific explanationscientific explanation to the question to the question being observed and researched. The being observed and researched. The statement must be testable. (“Which is statement must be testable. (“Which is best?” does not lend itself to being best?” does not lend itself to being tested). At the end of the investigation, tested). At the end of the investigation, you will either you will either acceptaccept or or rejectreject your your hypothesis.hypothesis.

5. Perform a controlled experiment - 5. Perform a controlled experiment - Develop and use the experimental design Develop and use the experimental design to test your hypothesis. Whenever to test your hypothesis. Whenever possible, the hypothesis should be tested possible, the hypothesis should be tested by an experiment in which only by an experiment in which only oneone variablevariable is changed at a time. All other is changed at a time. All other variables should be kept unchanged, or variables should be kept unchanged, or controlledcontrolled..

Testing fertilizers on plant growth? Keep all other factors constant!

Variables: Variables: Factor being testedFactor being tested• ControlledControlled- Variables that are kept - Variables that are kept

constantconstant• IndependentIndependent- Variable being manipulated - Variable being manipulated

(in a graph found on the x-axis or the (in a graph found on the x-axis or the horizontal axis)horizontal axis)

• DependentDependent- Variable that responds (in a - Variable that responds (in a graph found on the y-axis or the vertical graph found on the y-axis or the vertical axis)axis)

A way to remember variablesA way to remember variables

DDependentependent

RRespondingesponding

YY - - axisaxis

MManipulatedanipulated

IIndependentndependent

XX - - axisaxis

6. Observe again 6. Observe again - Collect data - Collect data (measurements) and perform (measurements) and perform analysisanalysis on on the data using graphs and chartsthe data using graphs and charts

7. Draw conclusions - 7. Draw conclusions - State whether or State whether or not the evidence not the evidence supportssupports the hypothesis the hypothesis based on your data and analysis.based on your data and analysis.

Please notice that we do not prove Please notice that we do not prove hypotheses! Proof exists when the chance hypotheses! Proof exists when the chance for error is 0. There is always some chance for error is 0. There is always some chance for error (no matter how small it is) and this for error (no matter how small it is) and this existence of chance error means we cannot existence of chance error means we cannot prove anything in true, honest, science. prove anything in true, honest, science.

8. Report back to 8. Report back to the community –the community – Experiments’ results Experiments’ results can be used by other can be used by other to help them with their to help them with their own experiments. own experiments. This is what keeps This is what keeps science science progressingprogressing. .

http://www.fnal.gov/pub/inquiring/physics/discoveries/images/baryon-talkLR.jpg

What is the difference between a What is the difference between a hypothesis, a theory, and a law?hypothesis, a theory, and a law?

A A hypothesishypothesis is a possible explanation is a possible explanation for a set of observations. It has not yet for a set of observations. It has not yet been thoroughly tested. been thoroughly tested.


A A theorytheory is a well tested explanation that is a well tested explanation that unifies a broad range of observations. A unifies a broad range of observations. A theory explains observations simply and theory explains observations simply and clearly, and predictions can be made from clearly, and predictions can be made from them. It is widely accepted by the them. It is widely accepted by the scientific community.scientific community.

Theory of Plate Tectonics


A A lawlaw is a summary of is a summary of observed natural observed natural events: they are less events: they are less comprehensive than comprehensive than theories and normally theories and normally are associated with a are associated with a mathematical mathematical expression. It is also expression. It is also widely accepted by widely accepted by the scientific the scientific community.community.

Law of Universal Gravitation

What is a scientist?What is a scientist?

Draw your perception of a scientist in Draw your perception of a scientist in the space belowthe space below

ScientistsScientists

Just your average joes…Just your average joes…

CharlesCharles

CharlesCharles

Cancer Researcher at MD Anderson

MeganMegan

MeganMegan

Field Biologist in southeast Texas

JeffJeff

JeffJeff

Wildlife Ecologist, Birder

AbeezarAbeezar

AbeezarAbeezar

Pediatrician

TonyTony

TonyTony

Physicist in New Zealand

KamranKamran

KamranKamran

Doctor, Comedian, Filmmaker

CindyCindy

CindyCindy

Environmental Control and Life Support Systems, NASA

Studying LifeStudying LifeWhat is Biology?What is Biology?

Etymology: “bio” means life, “-ology” means the study Etymology: “bio” means life, “-ology” means the study of-of-

Characteristics of Living Things: all living things have Characteristics of Living Things: all living things have all eight things in common:all eight things in common:

Studying LifeStudying Life1) They are made up of units called cells. 1) They are made up of units called cells.

2) Reproduction (sexually or asexually)2) Reproduction (sexually or asexually)

3) Has a universal 3) Has a universal genetic codegenetic code (DNA or RNA) (DNA or RNA)

4) 4) Grows and developsGrows and develops

5) Responds to the 5) Responds to the environmentenvironment

http://www.ciadvertising.org/studies/student/99_spring/theory/eileen/mytheo/passion3.gif

6) Obtains and uses 6) Obtains and uses materialsmaterials and and energyenergy

7) 7) homeostasis-homeostasis- maintains a stable internal environment maintains a stable internal environment

8) 8) Evolution-Evolution- Groups change over time Groups change over time

http://www.ichthus.info/Evolution/PICS/horse-evol.jpg

Branches of BiologyBranches of Biology – – Biology is studied at many levels of Biology is studied at many levels of

organization from simple to complex:organization from simple to complex: 1) Molecules – groups of atoms1) Molecules – groups of atoms

Atoms

Molecules

2) Cell – smallest functional unit of life2) Cell – smallest functional unit of life

3) Groups of cells – tissues, organs, and 3) Groups of cells – tissues, organs, and organ systemsorgan systems

http://68.90.81.6/ScienceTAKS/Integration/Cells_files/image022.jpg

4) Organism – individual living system4) Organism – individual living system

5) Population – group of organisms of one 5) Population – group of organisms of one type that live in the same areatype that live in the same area

6) Community – populations that live together 6) Community – populations that live together in a defined areain a defined area

7) Ecosystem – community and its nonliving 7) Ecosystem – community and its nonliving surroundingssurroundings

8) Biosphere – the part of Earth that 8) Biosphere – the part of Earth that contains all ecosystemscontains all ecosystems

http://oceancolor.gsfc.nasa.gov/SeaWiFS/ICONS/seawifs_biosphere_icon.jpg

Tools and Procedures Tools and Procedures (1-4)(1-4)

Biologists use metric measurement (the SI Biologists use metric measurement (the SI system) to gather and interpret data. system) to gather and interpret data.

SISI is the universal measurement system. is the universal measurement system.

Tools and Procedures (1-4)Tools and Procedures (1-4)

The metric system is The metric system is universal universal measurement system measurement system based on the number based on the number 10. The 10. The metermeter is the is the distance value, the distance value, the gramgram is the mass is the mass value, and the liter is value, and the liter is the the volumevolume value. value.

ConversionsConversions

ConversionsConversions

If you want to change a larger unit into a If you want to change a larger unit into a smaller unit, move the decimal point to the smaller unit, move the decimal point to the right.right.

If you want to change a smaller unit to a If you want to change a smaller unit to a larger unit move the decimal point to the larger unit move the decimal point to the left.left.

Example problems:Example problems: Convert 100 g to kg. Convert 100 g to kg.

100.0 g = 100.0 g =

0.0074 kL = ________________ L0.0074 kL = ________________ L

Scientific NotationScientific Notation

to make large or small numbers easier to to make large or small numbers easier to readread

Numbers that are very small (many Numbers that are very small (many numbers after the decimal) have numbers after the decimal) have negativenegative exponentsexponents

Numbers that are very large (many Numbers that are very large (many numbers before the decimal) have numbers before the decimal) have positivepositive exponentsexponents


The goal is to have a single non-zero number to The goal is to have a single non-zero number to the left of the decimal (1-9) and the exponent at the left of the decimal (1-9) and the exponent at the end tells you how many decimal places over the end tells you how many decimal places over in which direction you would move to get to the in which direction you would move to get to the original number. Scientific Notation is really only original number. Scientific Notation is really only useful if it will make the number shorter. If the useful if it will make the number shorter. If the number does not have several zeros in front or number does not have several zeros in front or behind of the number taking up space, scientific behind of the number taking up space, scientific notation will only make the number longer. Keep notation will only make the number longer. Keep this in mind when converting.this in mind when converting.


Example:Example: 0.0000000001 kg is easier to read as 1.0 x 100.0000000001 kg is easier to read as 1.0 x 10 -10-10 kg kg 1094600000 cm is easier to read as 1.0946 x 101094600000 cm is easier to read as 1.0946 x 1099 cm cm Practice problems:Practice problems: 1980084600000 g = _____________________1980084600000 g = _____________________ 0.00034568 cm = _______________________0.00034568 cm = _______________________ 14698 g = _____________________________14698 g = _____________________________

Graphing- Graphing- how a scientists shows how a scientists shows patterns in data collected.patterns in data collected.

There are several kinds of graphs; not all There are several kinds of graphs; not all of them are useful for data communication. of them are useful for data communication. Which type of graph is appropriate for Which type of graph is appropriate for which situations?which situations? Line graphLine graph - compares two things in which - compares two things in which

items on one axis affect the items on the other items on one axis affect the items on the other axis. If you are comparing anything to time, it axis. If you are comparing anything to time, it is usually a line graph. (Ex. Amount of CO2 is usually a line graph. (Ex. Amount of CO2 in the atmosphere over the last 6 decades)in the atmosphere over the last 6 decades)

Line GraphLine Graph

Bar graphBar graph - compares two or more values. - compares two or more values. (Ex. Number of students with red hair in each (Ex. Number of students with red hair in each class)class)

Bar GraphBar Graph

Pie Chart-Pie Chart- effective in showing proportions or effective in showing proportions or percentages of a whole thing. (Ex. percentages of a whole thing. (Ex. Comparing the percentage vote that each Comparing the percentage vote that each candidate received in the election)candidate received in the election)

Pie ChartPie Chart

GraphingGraphing

Always draw lines with a ruler, use pencil, and Always draw lines with a ruler, use pencil, and use map pencils when necessary. Make sure use map pencils when necessary. Make sure your graph contains all components:your graph contains all components: TitleTitle – tell what you are comparing or displaying (be – tell what you are comparing or displaying (be

descriptive).descriptive). X-axisX-axis – label – label andand give scale. give scale. Y-axisY-axis – label – label andand give scale. give scale. KeyKey – give meanings of the symbols and colors used – give meanings of the symbols and colors used

on the graph.on the graph. Data pointsData points – clearly marked, and label them if you do – clearly marked, and label them if you do

not have grid lines.not have grid lines.

MicroscopesMicroscopes

Biologists use microscopes to see living Biologists use microscopes to see living things that are too small for the unaided things that are too small for the unaided eye. The two basic categories of eye. The two basic categories of microscopes are:microscopes are:

1) Light microscope1) Light microscope – – produces magnified images by produces magnified images by focusing visible light rays. This microscope can be used to focusing visible light rays. This microscope can be used to

magnify up to 1000 timesmagnify up to 1000 times

2) Electron microscope2) Electron microscope – produce magnified images by – produce magnified images by focusing beams of electrons. This kind is used to magnify focusing beams of electrons. This kind is used to magnify

tens and hundreds of thousands of times for extremely tens and hundreds of thousands of times for extremely small object like a virus.small object like a virus.

Thehaironthelegofafly(magnifiedbyafactorof1000)

Saltcrystalsontheantennasofaninsect(magnifiedbyafactorof5000)

Other techniques and toolsOther techniques and tools

1.1. Cell culturesCell cultures - in - in order to study cells order to study cells under a controlled under a controlled condition, a biologist condition, a biologist can take a single can take a single cell and place it in a cell and place it in a Petri dish with Petri dish with nutrient solution to nutrient solution to help the cell help the cell regenerate and fill regenerate and fill the whole dish. This the whole dish. This cell culture can becell culture can be

used to isolate a single used to isolate a single kind of cell, or study kind of cell, or study interactions between interactions between cells and chemicals.cells and chemicals.


2. 2. Cell fractionationCell fractionation - in - in order to study a single order to study a single part of a cell, the cells part of a cell, the cells can be lysed (burst can be lysed (burst open) and the broken open) and the broken cells can be added to a cells can be added to a liquid and placed in a liquid and placed in a tube. This tube can be tube. This tube can be placed in a placed in a centrifugecentrifuge which spins the tubes which spins the tubes at high speeds whichat high speeds which

causes cell parts to settle at causes cell parts to settle at different levels based on different levels based on their density, the densest their density, the densest parts will land on the parts will land on the bottom. bottom.


3. 3. AutoclaveAutoclave - in order - in order to sterilize tools and to sterilize tools and kill anything a kill anything a scientist may have scientist may have been growing to been growing to test, the must kill it test, the must kill it with an autoclave. with an autoclave. The large steel The large steel machine uses heat machine uses heat and pressure to and pressure to raise the raise the temperaturetemperature

above normal boiling point above normal boiling point of water to a of water to a temperature in which no temperature in which no bacteria, viruses, or bacteria, viruses, or spores can survive.spores can survive.