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Discover the fascinating phenomenon of fish fossils found in Wyoming's dry desert at Fossil Butte. Join a scientist's journey to uncover the secrets behind these ancient sea-dwelling creatures. Explore the scientific methodology used to investigate and understand the natural world, and learn how to design controlled experiments to find answers.
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Biology-Chapter 1 The Nature of Life
Interest Grabber Understanding Fossil Butte Section 1-1 • In the southwest corner of Wyoming, there is a flat-topped mountain called Fossil Butte. A fossil of a fish was found near the top of Fossil Butte in a rock formation that is about 50 million years old. Fossils of other kinds of fishes, as well as turtles, have been found at Fossil Butte. The land around Fossil Butte is dry, and the Pacific Ocean is more than 1000 km away. How could fossils of sea-dwelling animals have formed at Fossil Butte? Go to Section:
Interest Grabber continued Section 1-1 • 1. Working with a partner, think of several questions that a scientist might ask in order to understand why there are fish fossils in the desert of Wyoming. Write these questions on a sheet of paper. • 2. Discuss your questions with your partner, and suggest a possible answer to each question. • 3. How could a scientist go about finding an answer to each of the questions? Go to Section:
I. What is Science ? A. The goal of science is to investigate and understand the natural world,to explain the events in the natural world ,and to use those explanations to make useful predictions. 1.deals only w/ natural world 2.uses systematic way of collecting info-_________looking for patterns and connections 3.__________________-propose explanations that can be tested Scientific method hypothesis
Always changing /open to testing and revisions/continues to advance • Is a way of knowing by gathering and analyzing info • Is a PROCESS –based on evidence and not belief
B. SCIENTIFIC METHODOLOGY/Thinking scientifically:ArthurSchropenhauer:”Thinking something that nobody has thought ,while looking at something everybody else sees”
Usually begin scientific thought w/ an *____________-gathering info about events or processing in careful , orderly way-using senses • *___________-info gathered from observations…..2 Types: observation data 1.Quantitative-expressed by numbers by counting or measuring 2. Qualitative --descriptive and involves that which can’t be counted
Thinking Like a Scientist cont’d • _____________________________-logical interpretation based on prior knowledge or experience….eg.If the bacterial count in water collected a few places on the Potomac @ Fairview Beach is high w/ infectious forms ,you can infer that all the water in that area is contaminated. Inference
X X X X X X X X Observation and Inference Section 1-1 • Object A is a basketball. • Object B is a table-tennis • ball. • Object C is a soccer ball. Statement Observation Inference Object A is round and orange. Object A is a basketball. Object C is round and black and white. Object C is larger than Object B. Object B is smooth. Object B is a table-tennis ball. Each object is used in a different sport. Go to Section:
Interest Grabber Mystery Worms Section 1-2 A teacher collected some beetles from a rotting log and placed them in a container of dry oatmeal in her classroom. She kept the box covered with a light cloth so that the beetles could not escape. She also asked one of her students to add potato and apple pieces once a week to provide food and moisture for the beetles. After several weeks, the student reported that there were some strange-looking, wormlike organisms in the container. Go to Section:
Interest Grabber continued Section 1-2 • 1. Formulate a hypothesis that might explain the presence of the “worms” in the container. • 2. How could you test your hypothesis? • 3. Identify the variables in your proposed experiment. Identify the control in your proposed experiment. Go to Section:
II. How Scientists Work- • Our ideas and knowledge has evolved greatly---From Aristotle(2300 years ago),when living things were thought to be able to be produced from nonliving--_______________...to 400 years ago when experimental science actually began Spontaneous generation
3.Designing an Controlled Experiment- • -All variables are kept the same-except one-All that remain the same are _____________________If not ,you will not know what caused your results CONSTANTS
3.Designing an Controlled Experiment- • 1. Ask a _______________. • Form a hypothesis: examples__If_______,then_____________________________. • Redi made the hypothesis that flies produce maggots and set up his experiment as follows: question
________________-factors that change • 1 variable @ a time to avoid confusion • Variable deliberately changed is called _________________ variable or IV-_____________ • Variable observed and it changes in response to IV-Responding variable –DV-________________________-usually a measured quantity • _________________is kept the same/except w/o IV/This is the baseline measurement or normal situation/This is VITAL for comparison/provides reliability to results Variables Manipulated/ independent Responding/dependent control
Figure 1-8 Redi’s Experiment on Spontaneous Generation HYPOTHESIS: Flies produce maggots. Section 1-2 OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat. PROCEDURE Uncovered jars Covered jars Controlled Variables: jars, type of meat, location, temperature, time Several days pass Manipulated Variables: gauze covering that keeps flies away from Meat (IV) Maggots appear No maggots appear Responding Variable: whether maggots Appear (DV) CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur.
Designing an experiment cont’d • Record and Analyze Data-typically data table that translates into graph • Draw conclusion –Is the hypothesis supported or not? • ****Research Tools-must choose appropriate tools and measurement devices ,etc. • *****SOURCES OF ERROR-must consider possible error in design and analysis…In medical studies the experimental and control groups are large! • Draw conclusion –Is the hypothesis supported or not?
B.Publish & report Investigations • Scientists read about and test one another's’ results • What did Needham do differently than Redi? ___________________ • What did Spallanzi do differently than Needham? ______________________ Needham boiled contents.
Figure 1-10 Spallanzani’s Experiment Section 1-2 Gravy is teeming with microorganisms. Gravy is boiled. Flask is open. Flask is sealed. Go to Section: Gravy is free of microorganisms. Gravy is boiled.
What did Pasteur do differently and what did he prove? Boiled broth would be free of microorganisms if air could get in,but dust and other particles left out---SPONTANEOUS GENERATION PROVEN WRONG !
C. When are experiments not possible?______Sometimes FIELD STUDIES instead of a lab are needed as w/ animal behavior For ethical or medical reasons-eg. Some studies are done on volunteers D. How a Theory Develops?----Results if hypothesis is continually supported and evidence builds up over a period of time……NOT an absolute truth!
D. How a Theory Develops---Results if hypothesis is continually supported and evidence builds up over a period of time……NOT an absolute truth! (MAY BE REVISED OR REPLACED)...In other conversations ,theory may mean something different-like an idea-****In science,Theory applies to a WELL TESTED explanation that unifies a broad range of observations and hypotheses that allow scientists to make accurate predictions about new situations-Example-Evolutionary Theory…
III. Studying Life- Biology • _________=study of life • A. Characteristics of Living Things • 1-made up of ________-living matter enclosed by a barrier-smallest unit considered alive • ____________-consists of only 1 cell…like paramecium • ___________made of more than 1 cell Cells unicellular multicellular
Characteristics cont’d DNA • 2-Reproduction-sexually(2 parents) or asexually (1 parent) • 3-_____-carries direction for heredity…There is an universal Genetic Code. • 4-Growth and Development • 5-Material use and Energy production-_____________=combination of chemical reactions through which an organism builds or breaks down materials • 6-Response • ___________-signal to which an organism responds • 7-Maintain Internal Balance-HOMEOSTASIS • 8-Evolution metabolism stimulus
Levels of organization: organs • Molecular –more than 1 atom—C6H12O6 • Cellular • Tissues-group of cells w/ particular function • _________-group of tissues that work together to perform closely related function • _________-group of organs that work together w/ a particular function • Population-group of organisms of one type in a particular area • __________-populations that work together in a defined area • _________-community and nonliving surroundings • Biosphere-Part of earth that contains all ecosystems Organ system community ecosystems
B-Branches of Biology zoologists • ____________-study animals • ___________-study plants • ______________-study ancient life • Molecular and Cell Biologists study @ the small level • Ecologists study the large units botanists Paleontologists
Big Ideas in Biology-interlocking central themes • Cellular Basis for Life-unicelluar/multicellular-more complex • Info and Heredity-DNA provides a universal genetic code • Matter and Energy-interdependent-use materials to produce energy • Growth, Development , and Reproduction • Homeostasis • Evolution
Structure and Function-related • Unity and Diversity-fundamental @ molecular level,but diverse in many ways • Interdependence_ all connected w/in biosphere • Science as a way of knowing-provides tools to learn more
IV. Tools & Procedures A.________________-used when collecting data and performing experiments…base 10 system…revised version called SI-International System of Units….******see p. 24 for basic units and abbreviations Metric system
B. Analyzing Bio Data 1-tables
Making a Graph From A Data Table Section 1-4 Water Released and Absorbed by Tree Absorbed by Roots (g/h) Released by Leaves (g/h) 20 Water released by leaves Time 15 1 2 8 AM 10 Relative Rates (g/h) 10 AM 5 1 12 PM 12 4 5 4 PM 2 PM 6 17 Water released by leaves 9 16 0 6 PM 14 10 10 AM 12 PM 2 PM 4 PM 6 PM 8 PM 8 AM 10 3 8 PM Time Go to Section:
3. Also computers-to directly transfer and analyze data and computer modeling
Microscopes-produce magnified images of structures that are too small to see • _____-produces images by focusing visible light---up to 1000x….Compound Light Microscope-light passes through image and uses 2 lenses/stains and dyes help highlight what is on slide • ______-magnifies by focusing beams of electrons/helps w/ images smaller than .2 micrometers/1000x more detailed than light version • TEMs-_________________-shine beam electrons through specimen Light microscope Electron microscope Transmission electron microscope
SEM-__________scan narrow beam back and forth across surface of a specimen-often 3-D images Scanning electron microscope TEM TEM image of bone tissue
SEM bone
D. Lab Techniques- • 1-_________-cell put in dish w/ nutrient solution/able to reproduce---tested for responses and interactions • 2-_____________-separate different cell parts as in centrifuge-quickly spins and more dense parts @ bottom. • E. Lab safety-see contract Cell culture Cell fractionation