Pick up a composition notebook Choose a seat Cut out the calendar and contents pages

1. 2. 3. Pick up a composition notebook Choose a seat Cut out the calendar and contents pages p o t p a l a t Ge the om. o m r o fr age r o t s

Review the syllabus

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HomeWork! Homework: Read sections 1.1 and 1.2 & take notes on 3X5, 4X6, or 5X8 Index Card (Notes may be used on reading quizzes)

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Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings Biology - the scientific study of life The phenomenon we call life Defies a simple, one-sentence definition We recognize life by what living things do

Image from: http://vilenski.org/science/safari/cellstructure/chloroplasts.htm Venus fly trap 2005 Pearson Education, Inc. publishing as Benjamin Cummings Image from: http://www.travel-net.com/~andrews/images/animations/traffic.gif Adapting - RESPOND TO the ENVIRONMENT (verb)

11 MAJOR THEMES that unify biology Connect concepts and provide a framework for understanding

Unifying Themes in Biology connect concepts & provide framework for understanding Evolution ~ biology s core theme; differential reproductive success Emergent Properties ~ the sum is greater than the parts The Cell ~ basic structure of all organisms Heritable Information ~ DNA Structure & Function ~ form follows function Environmental Interaction ~ organisms are open systems Energy and life ~ work requires energy that flows from sunlight to producers to consumers Regulation ~ feedback mechanisms Unity & Diversity ~ universal genetic code Scientific Inquiry ~ observation; testing; repeatability Science, Technology & Society ~ functions of our world

Evolution Evolution, biology s core theme, explains both the unity and diversity of life. The Darwinian theory of natural selection accounts for adaptation of populations to their environment through the differential reproductive success of varying individuals. http://images.encarta.msn.com/xrefmedia/aencmed/targets/illus/ilt/t014608a.gi f

EMERGENT PROPERTIESThe living world has a hierarchical organization, extending from molecules to the biosphere. With each step upward in level, system properties emerge as a result of interactions among components at the lower levels. Image from Pearson Education 2005, publishing as Benjamin Cummings

Cells are every organism s basic units of structure and function. The TWO main types of cells are: PROKARYOTES (bacteria & archaea) EUKARYOTES (protists, fungi, plants & animals) Image from Pearson Education 2005, publishing as Benjamin Cummings

HERITABLE INFORMATIONThe continuity of life depends on the inheritance of biological information in the form of DNA molecules. This genetic information in encoded in the nucleotide sequences of the DNA http://www.biosciences.bham.ac.uk/labs/minchin/tutorials/mddna.gif

Structure and Function Form and function are correlated at all levels of biological organization Images from Pearson Education 2005, publishing as Benjamin Cummings

Interdependence in Nature No organism is an island. Organisms are open systems that exchange materials and energy with their surroundings. Image from BIOLOGY ZONE by Kim B. Foglia

Sunlight Ecosystem Producers (plants and other photosynthetic organisms) Chemical Heat energy Consumers (including animals) Heat Energy and Life All organisms must perform work, which requires energy. Energy flows from sunlight to producers to consumers. Image from Pearson Education 2005, publishing as Benjamin Cummings

http://www.me-go.net/rtw/images/biggulp.jpg Regulation - Everything from cells to organisms to ecosystems is in a state of dynamic balance that must be controlled by positive or negative feedback mechanisms. http://pluck.typepad.com/photos/uncategorized/restroom_blog.gif

In feedback regulation The output, or product, of a process regulates that very process http://www.wildtech.org/images/feedback.gif

In negative feedback An accumulation of an end product slows the process that produces that product A Negative feedback Enzyme 1 B A Enzyme 1 B Enzyme 2 C C Enzyme 3 D D D D D D D D D D D Example: sugar breakdown generates ATP; excess ATP inhibits an enzyme near the beginning of the pathway

In positive feedback (less common) The end product speeds up production W W Enzyme 4 Enzyme 4 Positive feedback X X Enzyme 5 Enzyme 5 Y Y Enzyme 6 Z Enzyme 6 Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z EXAMPLE: Chemicals released by platelets that accumulate at injury site, attract MORE platelets to the site.

(Unity & Diversity) All species tend to maintain themselves from generation to generation using the same genetic code. However, there are genetic mechanisms that lead to change over time, or evolution. Image from Pearson Education 2005, publishing as Benjamin Cummings

... as diverse as life is, there is also evidence of remarkable unity 15 µm Cilia of Paramecium. The cilia of Paramecium propel the cell through pond water. 5 µm Cilia of windpipe cells. The cells that line the human windpipe are equipped with cilia that help keep the lungs clean by moving a film of debris-trapping mucus upward. 1.0 µm Cross section of cilium, as viewed with an electron microscope

Science as a Process - Science is a way of knowing. It can involve a discovery process using inductive reasoning, or it can be a process of hypothesis testing. Image from Pearson Education 2005, publishing as Benjamin Cummings

Science, Technology, and Society Scientific research often leads to technological advances that can have a positive and/or negative impacts on society as a whole. Image from Pearson Education 2005, publishing as Benjamin Cummings

Organelles 1 µm Cells Molecules Atoms 10 µm Tissues 50 µm Organs and organ systems

A Hierarchy of Biological Organization Biosphere Ecosystems Communities Populations Organisms

New properties emerge with each step up in hierarchy of biological order Structural arrangement and interaction of parts is important to function! http://www.cartoonstock.com/lowres/jmc0030l.jpg http://www.animationlibrary.com/sc/101/bicycling/?page= 1

EMERGENT PROPERTIES ~ the sum is greater than the parts Individual amino acids don t catalyze chemical reactions but proteins do! http://www.rpi.edu/dept/bcbp/molbiochem/mbweb/mb1/part2/images/dipeptide.gif http://www.biologie.uni-hamburg.de/b-online/library/cat-removed/enzyme_.gif

How can we understand biological systems? DILEMMA: Because of EMERGENT PROPERTIES we can t fully explain a higher level of order by breaking it into parts, but... organisms are too complex to analyze without taking them apart! TWO STRATEGIES : REDUCTIONISM SYSTEMS BIOLOGY

REDUCTIONISM Reducing complex systems to simpler components that are more manageable to study EXAMPLE: By studying the molecular structure of DNA, James Watson & Francis Crick were able to infer how this molecule could serve as the chemical basis of inheritance http://faculty.uca.edu/~johnc/mbi1440.htm http://www.hallucinogens.com/lsd/francis-crick.html

SYSTEMS BIOLOGY tries to understand how all parts are functionally integrated https://www.genome-sci.jp/english/images/zu2.gif

Systems biology Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings From body From lungs Right artium Right artium Right ventricle Right ventricle To lungs To body Seeks to create models Diagrams Graphs 3-D objects Computer programs Mathematical equations models of ideas, structures, and processes help us understand scientific phenomena and make predictions

Biologists use various forms of inquiry to explore life Biology blends two main processes of scientific inquiry Discovery science Hypothesis-based science

http://www.3g.co.uk/pr/august2006/casio.jpg http://www.bio-world.com/images/042135.jpg http://plus.maths.org/latestnews/may-aug05/millionaire/measure.jp g Types of Data DATA are recorded observations Can be: Quantitative involves analysis of numerical data (measure, count, etc) Qualitative involves analysis of data such as words (e.g., from interviews), pictures (e.g., video), or objects (e.g., an artifact). Copyright 2005 Pearson Education, Inc. publishing as Benjamin

Induction in Discovery Science In inductive reasoning Scientists derive generalizations based on a large number of specific observations EX: The sun always rises in the East. All living things are made of cells. http://virtualbible.net/literature/firstprinciples/inductive.jpg

Hypothesis-Based Science (Deductive reasoning) Inquiry that asks specific questions Usually involves the proposing and testing of hypothetical explanations, or hypotheses Hypothesis Is a tentative answer to a well-framed question, an explanation on trial Makes predictions that can be tested Usually expressed as an: If., then. statement

Deduction: The If then Logic of Hypothesis-Based Science In deductive reasoning The logic flows from the general to the specific If a hypothesis is correct Then we can expect a particular outcome

We all use hypotheses in solving everyday problems Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings Observations Questions Hypothesis # 1: Dead batteries Prediction: Replacing batteries will fix problem Test prediction Test falsifies hypothesis Hypothesis # 2: Burnt-out bulb Prediction: Replacing bulb will fix problem Test prediction Test does not falsify hypothesis

A Closer Look at Hypotheses in Scientific Inquiry A scientific hypothesis must have two important qualities It must be testable It must be falsifiable An hypothesis can only be proven to be FALSE, never proven to be TRUE!

The Myth of the Scientific Method The scientific method is an idealized process of inquiry There is not ONE method May design experiment, then backtrack when realize need more observations May redirect research if realize been barking up wrong tree Hind sight is 20/20

EXPERIMENTAL DESIGN A CONTROLLED experiment must see the effect of ONE VARIABLE at a time Hard to do in field/lab Don t eliminate unwanted variables. cancel their effects by using a CONTROL GROUP Must be repeated (at least 3 X) Can t ignore or rule out data which do not support the hypothesis

VARIABLES A variable is any factor, trait, or condition that can exist in differing amounts or types. independent variable is the one that is changed by the scientist. dependent variable is observed to see how it responds to the change made to the independent variable. The new value of the dependent variable is caused by and depends on the value of the independent variable. controlled variables. are quantities that a scientist wants to remain constant, and must be observed as carefully as the dependent variables.

HYPOTHESIS Independent variable (What I change) Dependent variable Controlled variables (What I observe) (What I keep the same) If fertilizer is Measure amount of Growth of the added, then a fertilizer (grams) plant measured by plant will grow its height bigger. Growth of the plant measured by the number of leaves There are other ways to measure growth Same size pot Same type of plant Same type and amount of soil Same amount of water and light Make measurements of growth for each plant at the same time The many variables above can each change how fast a plant grows, so to insure a fair test of the fertilizer, each of them must be kept the same for every pot.

IT S JUST A THEORY In every day conversation, a theory often implies an untested guess. In science, the word theory means something different than in common usage. Broader than a hypothesis General enough to spin off more hypotheses Supported by a massive body of evidence

IT S JUST A THEORY A theory is a well supported, testable explanation of natural phenomena. EX: Cell Theory, Gravitational theory, or Atomic theory http://www.avgoe.de/starchild/docs/starch00/questions/apple_falling.gi http://sixthsense.osfc.ac.uk/chemistry/atomic_structure2/atom.gi