1. Slide 1 of 21 Copyright Pearson Prentice Hall Biology

2. Slide 2 of 21 Copyright Pearson Prentice Hall 1-1 What Is Science?

3. Slide 3 of 21 Copyright Pearson Prentice Hall What Science Is and Is Not The goal of science is to: investigate and understand the natural world. explain events in the natural world. use those explanations to make useful predictions.

4. 1-1 What Is Science? Slide 4 of 21 Copyright Pearson Prentice Hall What Science Is and Is Not Science is an organized way of using evidence to learn about the natural world. The word science also refers to the body of knowledge that scientists have built up after years of using this process.

5. 1-1 What Is Science? Slide 5 of 21 Copyright Pearson Prentice Hall Thinking Like a Scientist Scientific thinking begins with observation. Observation is the process of gathering information about events or processes in a careful, orderly way. any info you gather through your senses can take many forms (length, speed, sound, color, etc)

6. 1-1 What Is Science? Slide 6 of 21 Copyright Pearson Prentice Hall Thinking Like a Scientist The information gathered from observations is called data. Quantitative data are expressed as numbers, obtained by counting or measuring. Qualitative data are descriptive and involve characteristics that can’t easily be measured.

7. 1-1 What Is Science? Slide 7 of 21 Copyright Pearson Prentice Hall Thinking Like a Scientist Scientists use data to make inferences. An inference is a logical interpretation based on prior knowledge or experience.

8. 1-1 What Is Science? Slide 8 of 21 Copyright Pearson Prentice Hall Explaining and Interpreting Evidence A hypothesis is a proposed scientific explanation for a set of observations. An educated guess/possible explanation or answer to a question A hypothesis may be ruled out or confirmed.

9. 1-1 What Is Science? Slide 9 of 21 Copyright Pearson Prentice Hall Explaining and Interpreting Evidence A hypothesis must be testable. Hypotheses are tested by performing controlled experiments or by gathering new data. To be valid, a conclusion must be based on logical interpretation of reliable data.

10. 1-1 What Is Science? Slide 10 of 21 Copyright Pearson Prentice Hall Science as a Way of Knowing Science is an ongoing process that involves: asking questions observing making inferences testing hypotheses

11. 1-1 What Is Science? Slide 11 of 21 Copyright Pearson Prentice Hall Science and Human Values An understanding of science and the scientific approach is essential to making intelligent decisions. Scientists make recommendations based on data collected through research.

12. 1-1 What Is Science? Slide 12 of 21 Copyright Pearson Prentice Hall Science and Human Values Decisions involve many factors besides scientific information, including: the society in which we live economic considerations laws moral principles Citizens decide what to do when they vote.

13. 1-1 What Is Science? Slide 13 of 21 Copyright Pearson Prentice Hall 1-2 How Scientists Work

14. 1-1 What Is Science? Slide 14 of 21 Copyright Pearson Prentice Hall Designing an Experiment How do scientists test hypotheses? Whenever possible, a hypothesis should be tested by an experiment in which only one variable is changed at a time. All other variables should be kept unchanged, or controlled.

15. 1-1 What Is Science? Slide 15 of 21 Copyright Pearson Prentice Hall Designing an Experiment Steps of Scientific Method Make Observations Ask a question Form a hypothesis Test Hypothesis Collect Data Analyze results Draw conclusions Communicate Results

16. 1-1 What Is Science? Slide 16 of 21 Copyright Pearson Prentice Hall Designing an Experiment Asking a Question Many years ago, people wanted to know how living things came into existence. They asked: How do organisms come into being?

17. 1-1 What Is Science? Slide 17 of 21 Copyright Pearson Prentice Hall Designing an Experiment Forming a Hypothesis One early hypothesis was spontaneous generation, or the idea that life could come from nonliving matter. For example, most people thought that maggots spontaneously appeared on meat. In 1668, Redi proposed a different hypothesis: that maggots came from eggs that flies laid on meat.

18. 1-1 What Is Science? Slide 18 of 21 Copyright Pearson Prentice Hall Designing an Experiment The process of testing a hypothesis includes: Setting up a controlled experiment Always test many individuals Repeat experiments many times

19. 1-1 What Is Science? Slide 19 of 21 Copyright Pearson Prentice Hall Designing an Experiment Setting Up a Controlled Experiment The variable that is deliberately changed is called the manipulated variable. The variable that is observed and that changes in response to the manipulated variable is called the responding variable.

20. 1-1 What Is Science? Slide 20 of 21 Copyright Pearson Prentice Hall Designing an Experiment Redi’s Experiment Controlled Variables: jars, type of meat, location, temperature, time Covered jars Uncovered jars

21. 1-1 What Is Science? Slide 21 of 21 Copyright Pearson Prentice Hall Designing an Experiment Redi’s Experiment Manipulated Variable: Gauze covering that keeps flies away from meat Responding Variable: whether maggots appear Maggots appear. Several days pass. No maggots appear.

22. 1-1 What Is Science? Slide 22 of 21 Copyright Pearson Prentice Hall Designing an Experiment Redi’s Experiment

23. 1-1 What Is Science? Slide 23 of 21 Copyright Pearson Prentice Hall Designing an Experiment Recording and Analyzing Results Scientists keep written records of their observations, or data. Sometimes drawings are used to record certain kinds of observations. organize data into tables, graphs what does the data mean?

24. 1-1 What Is Science? Slide 24 of 21 Copyright Pearson Prentice Hall Designing an Experiment Drawing a Conclusion Scientists use the data from an experiment to evaluate a hypothesis and draw a valid conclusion. Redi’s results supported the hypothesis that maggots were produced by flies, not spontaneous generation.

25. 1-1 What Is Science? Slide 25 of 21 Copyright Pearson Prentice Hall Repeating Investigations Scientists repeat experiments to be sure that the results match those already obtained.

26. 1-1 What Is Science? Slide 26 of 21 Copyright Pearson Prentice Hall Repeating Investigations Needham's Test of Redi's Findings Needham challenged Redi’s results by claiming that spontaneous generation could occur under the right conditions.

27. 1-1 What Is Science? Slide 27 of 21 Copyright Pearson Prentice Hall Repeating Investigations Needham’s Test of Redi’s Findings Needham sealed a bottle of gravy and heated it. After several days, the gravy was swarming with microorganisms. Needham concluded that these organisms came from the gravy by spontaneous generation.

28. 1-1 What Is Science? Slide 28 of 21 Copyright Pearson Prentice Hall Repeating Investigations Spallanzani's Test of Redi's Findings Gravy is boiled.

29. 1-1 What Is Science? Slide 29 of 21 Copyright Pearson Prentice Hall Repeating Investigations Spallanzani's Test of Redi's Findings Flask is open. Flask is sealed.

30. 1-1 What Is Science? Slide 30 of 21 Copyright Pearson Prentice Hall Repeating Investigations Spallanzani's Test of Redi's Findings Gravy is teeming with microorganisms. Gravy is free of microorganisms.

31. 1-1 What Is Science? Slide 31 of 21 Copyright Pearson Prentice Hall Repeating Investigations Pasteur's Test of Spontaneous Generation Louis Pasteur conclusively disproved the hypothesis of spontaneous generation. Pasteur showed that all living things come from other living things.

32. 1-1 What Is Science? Slide 32 of 21 Copyright Pearson Prentice Hall Repeating Investigations Pasteur’s Experiment Broth is boiled Broth is free of microorganisms for a year. Curved neck is removed. Broth is teeming with microorganisms.

33. 1-1 What Is Science? Slide 33 of 21 Copyright Pearson Prentice Hall Repeating Investigations The Impact of Pasteur’s Work Pasteur saved the French wine industry, which was troubled by unexplained souring of wine. He saved the silk industry, which was endangered by a silkworm disease. He began to uncover the nature of infectious diseases, showing that they were the result of microorganisms.

34. 1-1 What Is Science? Slide 34 of 21 Copyright Pearson Prentice Hall How a Theory Develops As evidence from numerous investigations builds up, a hypothesis may become so well supported that scientists consider it a theory. In science, the word theory applies to a well- tested explanation that unifies a broad range of observations.

35. 1-1 What Is Science? Slide 35 of 21 Copyright Pearson Prentice Hall How a Theory Develops No theory is considered absolute truth. As new evidence is uncovered, a theory may be revised or replaced by a more useful explanation.

36. 1-1 What Is Science? Slide 36 of 21 Copyright Pearson Prentice Hall Characteristics of Living Things No single characteristic is enough to describe a living thing. Some nonliving things share one or more traits with living things.

37. 1-1 What Is Science? Slide 37 of 21 Copyright Pearson Prentice Hall Characteristics of Living Things Living things share the following characteristics: made up of units called cells reproduce grow and develop based on a universal genetic code obtain and use materials and energy respond to their environment maintain a stable internal environment change over time

38. 1-1 What Is Science? Slide 38 of 21 Copyright Pearson Prentice Hall Characteristics of Living Things Living things are made up of cells. A cell is the smallest unit of an organism that can be considered alive.

39. 1-1 What Is Science? Slide 39 of 21 Copyright Pearson Prentice Hall Characteristics of Living Things Living things reproduce. In sexual reproduction, cells from two different parents unite to form the first cell of the new organism. In asexual reproduction, a single parent produces offspring that are identical to itself.

40. 1-1 What Is Science? Slide 40 of 21 Copyright Pearson Prentice Hall Characteristics of Living Things Living things grow and develop. During an organism’s development, cells differentiate, which means that the cells look different from one another and perform different functions.

41. 1-1 What Is Science? Slide 41 of 21 Copyright Pearson Prentice Hall Characteristics of Living Things Living things are based on a universal genetic code. Organisms store the information they need to live, grow, and reproduce in a genetic code in a molecule called DNA. Genes – set of instructions for making proteins (coded in DNA)

42. 1-1 What Is Science? Slide 42 of 21 Copyright Pearson Prentice Hall Characteristics of Living Things Living things obtain materials and use energy. The combination of chemical reactions through which an organism builds up or breaks down materials is called metabolism.

43. 1-1 What Is Science? Slide 43 of 21 Copyright Pearson Prentice Hall Characteristics of Living Things Living things respond to their environment. A stimulus is a signal to which an organism responds.

44. 1-1 What Is Science? Slide 44 of 21 Copyright Pearson Prentice Hall Characteristics of Living Things Living things maintain a stable internal environment. Although conditions outside an organism may change, conditions inside an organism tend to remain constant. This process is called homeostasis. Warm blooded or endotherms (seal has blubber) vs. cold blooded or ectotherms (snake basking in sun)

45. 1-1 What Is Science? Slide 45 of 21 Copyright Pearson Prentice Hall Characteristics of Living Things Taken as a group, livings things change over time. Over many generations, groups of organisms typically evolve. (evolution) Natural selection – favorable genes (characteristics) more likely to survive & reproduce

46. 1-1 What Is Science? Slide 46 of 21 Copyright Pearson Prentice Hall Big Ideas in Biology Science as a Way of Knowing Science is not just a list of “facts.” The job of science is to use observations, questions, and experiments to explain the natural world.

47. 1-1 What Is Science? Slide 47 of 21 Copyright Pearson Prentice Hall Big Ideas in Biology Interdependence in Nature All forms of life on Earth are connected together into a biosphere, which literally means “living planet.” The relationship between organisms and their environment depends on both the flow of energy and the cycling of matter.

48. 1-1 What Is Science? Slide 48 of 21 Copyright Pearson Prentice Hall Big Ideas in Biology Matter and Energy Life’s most basic requirements are matter that serves as nutrients to build body structure and energy to fuel the processes of life.

49. 1-1 What Is Science? Slide 49 of 21 Copyright Pearson Prentice Hall Big Ideas in Biology Cellular Basis of Life Organisms are composed of one or more cells, which are the smallest units that can be considered fully alive.

50. 1-1 What Is Science? Slide 50 of 21 Copyright Pearson Prentice Hall Big Ideas in Biology Information and Heredity Life’s processes are directed by information carried in a genetic code that is common, with minor variations, to every organism on Earth. That information, carried in DNA, is copied and passed from parents to offspring.

51. 1-1 What Is Science? Slide 51 of 21 Copyright Pearson Prentice Hall Big Ideas in Biology Unity and Diversity of Life All living things are fundamentally alike at the molecular level, even though life takes an almost unbelievable variety of forms.

52. 1-1 What Is Science? Slide 52 of 21 Copyright Pearson Prentice Hall Big Ideas in Biology Evolution In biology, evolution, or the change in living things through time, explains inherited similarities as well as the diversity of life.

53. 1-1 What Is Science? Slide 53 of 21 Copyright Pearson Prentice Hall Big Ideas in Biology Structure and Function Structures evolve in ways that make particular functions possible, allowing organisms to adapt to a wide range of environments.

54. 1-1 What Is Science? Slide 54 of 21 Copyright Pearson Prentice Hall Big Ideas in Biology Homeostasis An organism’s ability to maintain a relatively stable internal environment in the face of changing external conditions is vital to its survival.

55. 1-1 What Is Science? Slide 55 of 21 Copyright Pearson Prentice Hall Branches of Biology There are many branches of biology. For example: Zoologists study animals. Botanists study plants. Paleontologists study ancient life.

56. 1-1 What Is Science? Slide 56 of 21 Copyright Pearson Prentice Hall Branches of Biology Different levels at which life can be studied include: molecules cells organisms populations of a single kind of organism communities of different organisms in an area the biosphere

57. 1-1 What Is Science? Slide 57 of 21 Copyright Pearson Prentice Hall Branches of Biology Biosphere The part of Earth that contains all ecosystems

58. 1-1 What Is Science? Slide 58 of 21 Copyright Pearson Prentice Hall Branches of Biology Ecosystem Community and its nonliving surroundings Hawk, snake, bison, prairie dog, grass, stream, rocks, air

59. 1-1 What Is Science? Slide 59 of 21 Copyright Pearson Prentice Hall Branches of Biology Community Populations that live together in a defined area Hawk, snake, bison, prairie dog, grass

60. 1-1 What Is Science? Slide 60 of 21 Copyright Pearson Prentice Hall Branches of Biology Population Group of organisms of one type that live in the same area Bison herd

61. 1-1 What Is Science? Slide 61 of 21 Copyright Pearson Prentice Hall Branches of Biology Organism Individual living thing Bison

62. 1-1 What Is Science? Slide 62 of 21 Copyright Pearson Prentice Hall Branches of Biology Groups of Cells Tissues, organs, and organ systems Nervous tissue Brain Nervous system

63. 1-1 What Is Science? Slide 63 of 21 Copyright Pearson Prentice Hall Branches of Biology Cells Smallest functional unit of life Nerve cell

64. 1-1 What Is Science? Slide 64 of 21 Copyright Pearson Prentice Hall Branches of Biology Molecules Groups of atoms; smallest unit of most chemical compounds Water DNA

65. 1-1 What Is Science? Slide 65 of 21 Copyright Pearson Prentice Hall Branches of Biology At all these levels, smaller living systems are found within larger systems.

66. 1-1 What Is Science? Slide 66 of 21 Copyright Pearson Prentice Hall Biology in Everyday Life More than any other area of study, biology touches your life every day.

67. 1-1 What Is Science? Slide 67 of 21 Copyright Pearson Prentice Hall Biology in Everyday Life Biology provides information about the food you need and the methods for sustaining the world’s food supplies. Biology describes the conditions of good health and the behaviors and diseases that can harm you.

68. 1-1 What Is Science? Slide 68 of 21 Copyright Pearson Prentice Hall Biology in Everyday Life Biology is used to diagnose and treat medical problems. Biology identifies environmental factors that might threaten you.

69. 1-1 What Is Science? Slide 69 of 21 Copyright Pearson Prentice Hall Biology in Everyday Life Biology helps you understand what affects the quality of your life. Biology provides decision makers with useful information and analytical skills needed to predict and affect the future of the planet.

70. 1-1 What Is Science? Slide 70 of 21 Copyright Pearson Prentice Hall A Common Measurement System Scientists need a common system of measurements in order to replicate each other’s experiments.

71. 1-1 What Is Science? Slide 71 of 21 Copyright Pearson Prentice Hall A Common Measurement System Most scientists use the metric system when collecting data and performing experiments.

72. 1-1 What Is Science? Slide 72 of 21 Copyright Pearson Prentice Hall A Common Measurement System The metric system is a decimal system of measurement whose units are based on certain physical standards and are scaled on multiples of 10. Because the metric system is based on multiples of 10, it is easy to use.

73. 1-1 What Is Science? Slide 73 of 21 Copyright Pearson Prentice Hall A Common Measurement System A revised version of the original metric system is called the International System of Units, or SI.

74. 1-1 What Is Science? Slide 74 of 21 Copyright Pearson Prentice Hall A Common Measurement System 1 meter (m) = 100 centimeters (cm) 1 meter = 1000 millimeters (mm) 1000 meters = 1 kilometer (km) 1 kilogram (kg) = 1000 grams (g) 1 gram = 1000 milligrams (mg) 1000 kilograms = 1 metric ton (t) 0 0 C = freezing point of water 100 0 C = boiling point of water 1 liter (L) = 1000 milliliters (mL) 1 liter = 1000 cubic centimeters (cm 3 )

75. 1-1 What Is Science? Slide 75 of 21 Copyright Pearson Prentice Hall Analyzing Biological Data Scientists collect data to find out whether certain factors change or remain the same. Often, the simplest way to do that is to record the data in a table and then make a graph.

76. 1-1 What Is Science? Slide 76 of 21 Copyright Pearson Prentice Hall Microscopes Microscopes are devices that produce magnified images of structures that are too small to see with the unaided eye.

77. 1-1 What Is Science? Slide 77 of 21 Copyright Pearson Prentice Hall Microscopes Light Microscopes The most commonly used microscope is the light microscope. (uses visible light rays) Light microscopes produce clear images of objects at a magnification of about 1000 times.

78. 1-1 What Is Science? Slide 78 of 21 Copyright Pearson Prentice Hall Microscopes Compound light microscopes allow light to pass through the specimen and use two lenses to form an image. Light microscopes make it possible to study dead organisms and their parts, and to observe some small organisms and cells while they are still alive.

79. 1-1 What Is Science? Slide 79 of 21 Copyright Pearson Prentice Hall Microscopes Electron Microscopes Light microscopes cannot produce clear images of objects smaller than 0.2 micrometers, or about one-fiftieth the diameter of a typical cell. To study even smaller objects, scientists use electron microscopes.

80. 1-1 What Is Science? Slide 80 of 21 Copyright Pearson Prentice Hall Microscopes Electron microscopes use beams of electrons, rather than light, to produce images. The best electron microscopes can produce images almost 1000 times more detailed than light microscopes can.