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Unit 1 pp
- 1. UNIT 1: INTRODUCTION TO BIOLOGY TIMBERLANE HIGH SCHOOL MEGHIN MARLEY
- 2. WHAT IS SCIENCE? •An organized way of using evidence to learn about the natural world. • The word science can also be used to describe what humans already know about the natural world. • It’s important to avoid opinions and biases in science so actual facts can be presented.
- 3. HOW DO HUMANSEXPLORE SCIENCE? • Observe • Describe • Experiment • Read • Research • Explore • What are some words or processes that come to mind when you think about exploring science?
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- 5. OBSERVATION • Involves observingsomething with one or more of your senses • Using your senses to gather information • Which senses do you believe would be most useful in gathering scientific information or data? • Sight • Sound • Touch • Smell • And sometimes even taste
- 6. OBSERVATION • 1. Quantitative-involves numbers, counting or measuring • 2. Qualitative- observations that cannot be counted or measured • Observations are used in collecting data and the formation of evidence
- 7. EVIDENCE INTERPRETATION • Whathappens after the observations are made? • How are the observations used to provide an understanding of the process you are trying to explain? • Inference: a logical explanation or interpretation based on prior knowledge/experience of the subject
- 8. HOW ARE SCIENTIFICIDEAS TESTED? • Once someone has formed a scientific question what is the next step? • The Scientific Method can be used to test a hypothesis.
- 9. THE BASIC STEPS •1. Ask a Question • 2. Form a Hypothesis • 3.Design and Conduct an Experiment • 4. Analyze Results of the Experiment • 5. Draw Conclusion
- 10. THE SCIENTIFIC METHOD •http://www.youtube.com/watch?v=LMg_asQ3Hto
- 11. HYPOTHESIS • Can answera scientific question • Can describe scientific information • A possible explanation • Hypotheses can be tested usually through controlled experimentation • Sometimes hypotheses are wrong • In an If…then format
- 12. ALTERNATIVE HYPOTHESES • H1, H 2, H 3 • Alternative hypotheses are more likely to be correct • Multiple alternative hypotheses can be generated and tested.
- 13. THE SCIENTIFIC METHOD •Monty Python • http://www.youtube.com/watch?v=k2MhMsLn9B0
- 14. NULL HYPOTHESIS • H0 •The null hypothesis is a hypothesis which the researcher tries to disprove, reject or nullify • The 'null' often refers to the common view of something, while the alternative hypothesis is what the researcher really thinks is the cause of a phenomenon.
- 15. THE STEPS • Do all scientific investigations include all the steps? • No • Do some investigations include more steps? • Yes • The scientific method is the basis for scientific investigation, but it is not set in stone. • It is a process to help direct scientific inquiry, more steps, research, or experimentation can be necessary.
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- 17. CR: 3 Why isthe scientific method important for answering scientific questions? Do your best to describe the process of the scientific method step by step.
- 18. THE PROCESS OFSCIENTIFIC INVESTIGATION • The Process of Scientific Investigation can be done in a series of stages, formal research and testing is carried out in this manor. • 1. Observations • 2. Form Hypotheses • 3. Predictions • 4. Experimentation • 5. Make conclusions
- 19. EXPERIMENTAL DESIGN • Developingand setting up a controlled experiment to test your hypothesis • Controlled Experiment: When only one variable is changed at a time • Manipulated variable: variable that is deliberately changed • Responding variable: variable that is observed and changes in response to the manipulated variable
- 20. MORE ON VARIABLES •Independent Variable- researcher can control, concentration of a chemical, timing of measurements • (manipulated variable) • Dependent Variable- response that is measured • (responding variable)
- 21. CONTROLLED EXPERIMENTS • Whatdoes it mean to have a controlled experiment? • When an experiment is run, one variable is altered and the all other variables will remain constant. • A controlled experiment will be run the same way but no variables will be altered and all other variables will be kept constant.
- 22. DRAWING CONCLUSIONS • Datafrom experiments is evaluated • The hypothesis is supported or rejected
- 23. THEORIES • Once youhave supported your hypothesis through testing does it become a theory? • What is a theory? • A theory is a well supported explanation involving a broad range of observations for a particular phenomenon • Multiple investigations have been done and proven the hypothesis to be true
- 24. THEORIES • Theories canbe widely excepted, but should not be considered absolute truth • New evidence may be uncovered • New technologies can lead to new discoveries
- 25. REDI’S EXPERIMENT • Inancient times people did not understand many biological lifecycles, people accepted the idea that some organisms, fruit-flies, maggots, would suddenly just appear • Spontaneous Generation- sudden appearance of organisms from non-living matter
- 26. REDI’S EXPERIMENT • In1668 Francesco Redi observed flies on meat and several days later the appearance of maggot, he wanted to test his hypothesis that maggots came from flies and developed a controlled experiment. • He used 8 jars, 4 he left open to the air and 4 he covered with muslin, a fabric that prevented flies from getting to the meat.
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- 28. REDI’S EXPERIMENT • Whatwas the control group? • The jars that were left uncovered • This was the way meat was typically kept • His hypothesis was that flies were causing the production of maggots on the meat • He was able to prove that the flies were causing the maggots by covering the jars, preventing the flies from laying eggs in the meat.
- 29. VARIABLES IN REDI’SEXPERIMENT • Manipulated Variables: • Muslin covering the jars • Responding Variables: • The maggots appearing or not • Variables that were controlled: • Jars, type of meat, location, temperature, time
- 30. JOHN NEEDHAM • Mid-1700’s •Englishman • Used a sealed jar of gravy to try and disprove Redi’s claim on spontaneous generation • He took a jar of gravy and sealed it • He then heated the gravy “killing off all possible microorganisms” • After several days he examined the gravy, found microorganisms and claimed they could have only came from the gravy, since the jar was sealed.
- 31. JOHN NEEDHAM • Whydo you think there were organisms in the gravy? • Do you think Needham’s findings disproved the work of Redi? • Was Needham’s experiment controlled?
- 32. SPALLANZANI’S EXPERIEMENT • ItalianScholar • An improvement on Needham’s experiment • He believed that the gravy had not been heated enough to kill all the existing microorganisms • Preformed a similar experiment to Redi’s
- 34. SPALLANZANI’S EXPERIMENT • Spallanzaniclaimed that the gravy left open grew microorganisms that had entered from the air, the sealed flask had no living organisms. • He concluded that non-living gravy could not produce living things • What was the control group in Spallanzani’s experiment? • Gravy flask left unsealed • The manipulated variable was the sealing of the flask • The responding variable was microorganism growth • He sealed the flask and prevented microorganism growth
- 35. LOUIS PASTEUR • Famousproblem solver, Microbiologist • In 1864 Louis Pasteur designed a flask with a curved neck so that air could get into the flask, but microorganisms could not • Other works of Pasteur • Saved French wine industry when wine was souring • Saved the silk industry through discovery of a silkworm disease • Discovered and worked with infectious diseases • Vaccine for Anthrax bacterial infection in 1881
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- 37. LOUIS PASTEUR’S GERMTHEORY
- 38. CAN EVERYTHING SCIENTIFICBE TESTED BY EXPERIMENTATION? • Animal and insect life cycles • The Great White Shark is hard to keep in captivity • Ecological Interactions • How do you simulate all the different environmental factors in a controlled way? • Human Ethics • Stem cell research • Testing on humans and animals
- 39. ALTERNATIVES TO CONTROLLED EXPERIMENTS • Field Studies • Observation of animals or other living things in their natural environment • Studies involving large amounts of people or subjects • More samples gives more reliable data • Control of as many factors as possible • In a medical study for cancer, people with other health issues may be eliminated • It is important to research what is already out there. What has been done on the subject? • Cite your sources!
- 40. So how arewe going to use this information about science and the process of scientific investigation to learn about Biology?
- 41. SO WHAT ISBIOLOGY? • Textbook definition: A field of science that seeks to understand the living world. The study of life. • The study of things that are “living”. • What does it mean to be “alive”? • What are some characteristics that help people determine whether something is living or non?
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- 46. THE CHARACTERISTICS OFLIFE • Made up of units called cells • Maintain stable internal conditions: homeostasis • Grow and develop • Reproduce • Based on a universal genetic code • Obtain and use materials and energy • Respond to their environment • When looking at a species as a whole, living things can change over time or evolve
- 47. THE CELL • Whatis a Cell? • A cell is a collection of living matter surrounded by a membrane that separates it from its surrounding environment. • How are cells organized?
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- 50. CELLULAR ORGANIZATION • All living things are made up of one or more cells • Cells can be simple to very complex • Cells can grow and reproduce • Single-Celled Organisms • Algae • Bacteria • Paramecia, A protist • There are around 100 trillion cells in the human body
- 51. HOMEOSTASIS • Living thingsmust expend energy to keep their cells within certain limits for proper form and function • Organisms are able to maintain certain internal environments even when the environment outside of them is constantly changing • An organism's ability to do this allows them to survive
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- 53. GROWTH & DEVELOPMENT •Every different organism has a specific pattern of growth • A single egg cell once fertilized can divide over and over • Cells differentiate forming tissues and organs
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- 57. REPRODUCTION • The reproductionof new generations • Asexual • Sexual reproduction • Most plants and organisms use sexual reproduction
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- 60. UNIVERSAL GENETIC CODE •Information needed to live and grow is stored in complex molecules called DNA • DNA stores the information for genes and traits of an organism • DNA is the method for passing down genetic information to the next generation
- 61. USE OF MATERIALSAND ENERGY • Organisms must use materials from the earth and energy from the sun to live and grow • Chemicals/Nutrients from the earth • Energy from the sun helps plants and other photosynthetic organisms produce food
- 62. METABOLISM • Living thingsneed energy • Life functions require energy • Transforming energy from one form to another with in cells is metabolism
- 63. RESPOND TO THEIRENVIRONMENT • Organisms can detect and react to different signals within their environment • Stimuli: signal to which an organism responds
- 64. EVOLVE OVER TIME •Populations of organisms change over time • Natural selection: Individuals more well suited for their environment will do better and will reproduce more then other individuals
- 65. CR:4 • What doesit mean to be alive? Discuss what it means to you; think about the characteristics of life. • Or • Design an experiment: If you were given an unknown substance, what kinds of tests could you preform to find out if that item was living or non- living?
- 66. CHARACTERISTICS OF LIFE ASSIGNMENT • Today you will explore all the characteristics of life for a single organism • Pick any organism you would like, tell you instructor what you choose; grab paper, pencils, markers, whatever you would like to use • Make a flow diagram of your organism fulfilling all the different characteristics of life.
- 67. SCIENTISTS OF BIOLOGY •Zoologists: Animals • Botanists: Plants • Ethologists: Animal Behavior • Paleontologists: Life in the past
- 68. LEVELS OF ORGANIZATION • Molecules • Cells • Groups of cells • Organism • Population community • Ecosystem • Biosphere
- 70. • CR:5 • Describehow you fulfill the 8 characteristics of life. Use your notes if you can’t remember all 8.