THE SCIENCE OF BIOLOGY

2 CIDEB 1.1 What is science?  Science is an organized way of using evidence to learn about the natural world  A word that refers to the body of knowledge that scientists have built up after years of using this process.

3 CIDEB 1.1 What is science?  Scientific thinking begins with  Observation process of gathering information about events or processes in a careful orderly way.  Data  Information gathered from observation

4 CIDEB 1.1 What is science?  Inference  Logical interpretation based on prior knowledge or experience

5 CIDEB 1.1 What is science?  After observations  Hypothesis  A proposed scientific explanation for a set of observations

6 CIDEB 1.1 What is science?  Science is an ongoing process, involves:  Asking questions  Observing  Making inferences  Testing hypothesis  It is always changing

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9 1.1 What is science?  Make a list of things that you need to understand to protect your life and the lives of others close to you.

10 CIDEB StatementObservation 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. X X X X X X X X  Object A is a basketball.  Object B is a table-tennis ball.  Object C is a soccer ball. Section 1-1 Observation and Inference

11 CIDEB Moldy Bread

12 CIDEB 1.2 How scientists work  Steps for designing an experiment:  Ask a question  Form a hypothesis  Set up a controlled experiment  Record and analyze results  Draw a conclusion

13 CIDEB 1.2 How scientists work  Steps for designing an experiment:  Ask a question How do new living things come into being?  Form a hypothesis Life could arise from nonliving matter  Set up a controlled experiment (Redi´s experiment)  Record and analyze results Keep records  Draw a conclusion Evaluate the hypothesis

14 CIDEB 1.2 How scientists work

15 CIDEB Designing an Experiment Section 1-2 Flowchart State the Problem Form a Hypothesis Set Up a Controlled Experiment Record Results Analyze Results Draw a Conclusion Publish Results

16 CIDEB 1.2 How scientists work  Anton van Leeuwenhoek  Tiny animals  John Needham  Spontaneous generation could occur under the right conditions  Leeuwenhoek

17 CIDEB HYPOTHESIS: Flies produce maggots. OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat. PROCEDURE Controlled Variables: jars, type of meat, location, temperature, time Manipulated Variables: gauze covering that keeps flies away from meat Uncovered jarsCovered jars Several days pass Maggots appearNo maggots appear Responding Variable: whether maggots appear CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur. Section 1-2 Figure 1-8 Redi’s Experiment on Spontaneous Generation Redi´s Experiment

18 CIDEB 1.2 How scientists work  Spallanzani´s test of Redi´s findings.  Supported the hypothesis that new organisms are produced only by existing organisms

19 CIDEB Gravy is boiled.Flask is open. Gravy is teeming with microorganisms. Gravy is boiled. Flask is sealed. Gravy is free of microorganisms. Section 1-2 Figure 1-10 Spallanzani’s Experiment Spallanzani´s experiment

20 CIDEB 1.2 How scientists work  Pasteur´s test of Spontaneous generation

21 CIDEB 1.2 How scientists work  Pasteur´s test of Spontaneous generation Broth is boiled. Broth is free of microorganisms for a year. Broth is teeming with microorganisms. Curved neck is removed.

22 CIDEB 1.2 How scientists work  Theory:  A well-tested explanation that unifies a broad range of observations.  Scientists make accurate predictions about new situations.

23 CIDEB 1.3 Studying life  Biology seeks to understand the living world.

24 CIDEB 1.3 Studying life  Characteristics of living things:  Are made up of units called cells  Reproduce  Are based on a universal genetic code  Grow and develop  Obtain and use materials and energy  Respond to their environment  Maintain a stable internal environment  Change over time

25 CIDEB CharacteristicExamples Living things are made up of units called cells. Living things reproduce. Living things are based on a universal genetic code. Living things grow and develop. Living things obtain and use materials and energy. Living things respond to their environment. Living things maintain a stable internal environment. Taken as a group, living things change over time. Many microorganisms consist of only a single cell. Animals and trees are multicellular. Maple trees reproduce sexually. A hydra can reproduce asexually by budding. Flies produce flies. Dogs produce dogs. Seeds from maple trees produce maple trees. Flies begin life as eggs, then become maggots, and then become adult flies. Plants obtain their energy from sunlight. Animals obtain their energy from the food they eat. Leaves and stems of plants grow toward light. Despite changes in the temperature of the environment, a robin maintains a constant body temperature. Plants that live in the desert survive because they have become adapted to the conditions of the desert. Section 1-3 Characteristics of Living Things Characteristics of living things

26 CIDEB 1.3 Studying life  Made up of cells

27 CIDEB 1.3 Studying life  Reproduction  Sexual  Asexual

28 CIDEB 1.3 Studying life  Based on a genetic code  Offsrping usually resemble their parents.

29 CIDEB 1.3 Studying life  Growth and development

30 CIDEB 1.3 Studying life  Need for materials and energy  Metabolism  Photosynthesis  Consumers  Decomposers

31 CIDEB 1.3 Studying life  Response to the environment  Stimulus: signal to which an organism responds

32 CIDEB 1.3 Studying life  Maintaining internal balance  Homeostasis

33 CIDEB Is it alive?????

34 CIDEB 1.3 Studying life  Evolution

35 CIDEB 1.3 Studying life  Branches of Biology:  Zoologists study animals  Botanists study plants  Paleontologists study ancient life

36 CIDEB Biosphere Ecosystem Community Population The part of Earth that contains all ecosystems Community and its nonliving surroundings Populations that live together in a defined area Group of organisms of one type that live in the same area Biosphere Hawk, snake, bison, prairie dog, grass, stream, rocks, air Hawk, snake, bison, prairie dog, grass Bison herd Figure 1-21 Levels of Organization Levels of Organization

37 CIDEB Organism Groups of Cells Molecules Individual living thing Tissues, organs, and organ systems Smallest functional unit of life Groups of atoms; smallest unit of most chemical compounds Bison Nervous tissue Nervous system Brain Nerve cell Water DNA Levels of Organization continued

38 CIDEB 1.4 Tools and procedures  Scientists collect data  Record in a table  Make a graph  See the pattern

39 CIDEB 10 AM 2 PM 6 PM Water released by leaves Water Released and Absorbed by Tree Time Absorbed by Roots (g/h) Released by Leaves (g/h) 8 AM 12 PM 4 PM 8 PM Water absorbed by roots Relative Rates (g/h) 20 Time AM10 AM12 PM2 PM4 PM6 PM8 PM On which axis is time recorded? On which axis are the relative rates recorded? What pattern does the graph show at a glance about water given off and taken in by a tree? 4

40 CIDEB 1.4 Tools and procedures  Microscopes  Light Microscopes Electron Microscopes Produce magnifies images by focusing visible light rays Produce magnified images by focusing beams of electrons

41 CIDEB 1.4 Tools and procedures Magnification of about 1000 times Allow light to pass Through the specimen and use Two lenses to form an image Techniques and procedures

42 CIDEB 1.4 Tools and procedures ELECTRON MICROSCOPE Use beams of electrons to produce images

43 CIDEB 1.4 Tools and procedures TEM: Transmission Electron Microscopes: Shine a beam of electrons through the specimen Tems reveal details inside the cell SEM: Scanning Electtron Microscopes: Scan a narrow beam of electrons back and forth across The surface of a specimen SEMs produce realistic three-dimensional images of the Surfaces of objects

44 CIDEB 1.4 Tools and procedures  Cell cultures:  Dish containing a nutrient solution where a cell or cells are placed to reproduce

45 CIDEB 1.4 Tools and procedures  Cell Fractionation  Technique to separate the different cell parts

46 CIDEB 1.4 Tools and procedures  THE MOST IMPORTANT RULE FOR YOUR SAFETY  ALWAYS FOLLOW YOUR TEACHER´S INSTRUCTIONS AND THE TEXTBOOK DIRECTIONS EXACTLY

47 CIDEB CHAPTER 1 THE END