BiologyChapter 1 The Nature of Life Interest Grabber

Biology-Chapter 1 The Nature of Life

Interest Grabber Section 1 -1 n Go to Section: In the southwest corner of Wyoming, there is a flat-topped mountain called Fossil Butte. A fossil. Understanding of a fish was found Fossil near the top of Butte 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?

Interest Grabber continued Section 1 -1 n n n Go to Section: 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?

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

n n 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

n B. SCIENTIFIC METHODOLOGY/Thinking scientifically: Arthur Schropenhauer: ”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 n _______________-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

Observation and Inference Section 1 -1 Statement Observation Inference Object A is round and orange. X X Object A is a basketball. Object C is round and black and white. X Object C is larger than Object B. X Object B is smooth. X Object B is a table-tennis ball. Each object is used in a different sport. X Go to Section: n n X X n n Object A is a basketball. Object B is a tab -tennis ball. Object C is a soccer ball.

Section 1 -2 Interest Grabber Mystery Worms 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 n n n 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 Workn 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 Experimentn -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 ________. n Form a hypothesis: examples__If_______, then___________. Redi made the hypothesis that flies produce maggots and set up his experiment as follows: n n question

n n n ________-factors that change Variables 1 variable @ a time to avoid confusion Manipulated/ Variable deliberately changed is called _________ variable or IVindependent _______ Variable observed and it changes in Responding/ response to IV-Responding variable – DV-____________-usually dependent 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 control

Figure 1 -8 Redi’s Experiment on Spontaneous Generation Section 1 -2 HYPOTHESIS: Flies produce maggots. OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the mea PROCEDURE Uncovered jars Controlled Variables: jars, type of meat, location, temperature, time Manipulated Variables: gauze covering that keeps flies away from Meat (IV) Responding Variable: whether maggots Appear (DV) Covered jars Several days pass Maggots appear No maggots appear CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur.

Designing an experiment cont’d n n 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! n Draw conclusion –Is the hypothesis supported or not?

B. Publish & report Investigations n n n 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.

Spallanzani boiled contents longer and sealed contents.

Figure 1 -10 Spallanzani’s Experiment Section 1 -2 Gravy is boiled. Flask is open. Gravy is teeming with microorganisms. Flask is sealed. Go to Section: Gravy is boiled. Gravy is free of microorganisms.

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 D. How a Theory Develops? ----Results if hypothesis is continually supported and evidence builds up over a period of time……NOT an absolute truth! For ethical or medical reasonseg. 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! (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 n n n _____=study of life Cells A. Characteristics of Living Things 1 -made up of ____-living matter enclosed by a barrier-smallest unit considered alive unicellular n ______-consists of only 1 n cell…like paramecium ______made of more than 1 cell multicellular

Characteristics cont’d n n n n 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

organs Levels of organization: n n n n n Organ system Molecular –more than 1 atom—C 6 H 12 O 6 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 community ecosystems

B-Branches of Biology zoologists n n n ______-study animals botanists ______-study plants _______-study ancient life Molecular and Cell Biologists study @ the small level Paleontologists Ecologists study the large units

Big Ideas in Biology-interlocking central themes n n n Cellular Basis for Life-unicelluar/multicellularmore 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

n n 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

Metric system-SI UNITS Length- 1 m=100 cm=1000 mm 1000 m=1 km Mass-1 kg=1000 g 1 g=1000 mg 1000 kg =1 metric ton Volume-1 L=1000 m. L=1000 cm 3(used in solid and medicine volume—cc) Temperature-0 C=freezing water/100 C =boiling point water

B. Analyzing Bio Data 1 -tables animal Respiration rate indoors outdoors cat 15 17 breaths/min. bird 20 22 breaths/min.

1. convert tables to graphs

Making a Graph From A Data Table Section 1 -4 Time 8 AM 10 12 PM AM 4 PM 2 PM 6 PM 8 PM Go to Section: Absorbed by Roots (g/h) Released by Leaves (g/h) 1 1 4 6 9 14 10 2 5 12 17 16 10 3 Relative Rates (g/h) Water Released and Absorbed by Tree 20 Water released by leaves 15 10 5 Water released by leaves 0 8 AM 10 AM 12 PM 4 PM 6 PM 8 PM Time

3. Also computers -to directly transfer and analyze data and computer modeling

Microscopes-produce magnified images of structures that are too small to see n n _____ produces images by focusing visible light---up to 1000 x…. 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/1000 x more detailed than light version - n TEMs-_________-shine beam electrons through specimen Light microscope Electron microscope Transmission electron microscope

SEM-_____scan narrow Scanning beam back and forth across electron surface of a specimen-often 3 -D microscope images TEM image of bone tissue

SEM bone

D. Lab Techniquesn n n 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