3. 1-1 What Is Science? What is the goal of science? investigate and understand, & explain events in the natural world. use those explanations to make useful predictions.

4. Science: an organized way of using evidence to learn about the natural world; also refers to the body of knowledge that scientists have built up after years of using this process.

5. Thinking Like a Scientist Scientific thinking begins with ___________. Observation is the process of gathering information about events or processes in a careful, orderly way. observation

6. 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. Scientists use data to make inferences: a logical interpretation based on prior knowledge or experience. Explaining and Interpreting Evidence A hypothesis is a proposed scientific explanation for a set of observations. A hypothesis may be ruled out or confirmed. A hypothesis must be proposed in a way that can be tested. Hypotheses are tested by performing controlled experiments or by gathering new data.

8. Scientific methods Observation: Events/objects seen cause questions which lead to making a: Hypothesis: a statement usually framed as “If... Then” which answers a question, which leads to an: Experiment: test(s) of the hypothesis to determine if it is true or false Experimental groups are compared with control groups Control groups are left as “normal” and only one factor is changed in treating an experimental group. Results of the experiment may lead to a: Theory: explain natural phenomena; based on many experiments

9. Scientific understanding is always changing. Good scientists are skeptics who question both existing ideas and new hypotheses.

10. 1–1 Section Quiz Observations involving numbers are known as a)qualitative observations. b)hypothetical observations. c)quantitative observations. d)inferred observations.

11. Which of the following shows the interaction of science and human values? a)the debate over the best way to produce electricity b)investigating how a manatee behaves c)Determining what causes a disease d)using a hypothesis to test an explanation 1–1 Section Quiz

12. A scientist takes paint chips from 10 apartments in a large building. She tests for the presence of lead in the paint and finds it in all 10 samples. She then concludes that lead paint is probably present in all 120 apartments in the building. This conclusion is an example of a)a scientific fact. b)a scientific error. c)proof. d)a reasonable inference.

13. 1–1 Section Quiz A possible explanation for a set of observations is known as a)data. b)a hypothesis. c)an inference. d)a result.

14. 1–1 Section Quiz A good scientific hypothesis must be a)correct. b)able to be tested. c)obvious. d)based on common sense.

16. Asking a Question Many years ago, people wanted to know how living things came into existence. They asked: How do organisms come into being? This led to several very different hypotheses about the origins of life… many of which where subsequently proven wrong. But how is a good hypothesis created and tested?

17. 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.

18. Forming a Hypothesis on the Origin of Life 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.

19. People Who Rocked The Boat Redi Spallanzani Pasteur

20. Redi In 1668, Francesco Redi proposed a different hypothesis than spontaneous generation: that maggots came from eggs that flies laid on meat.

21. 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.

22. Designing an Experiment Redi’s Experiment Controlled Variables: jars, type of meat, Location, temperature, time Covered jars Uncovered jars

24. Recording and Analyzing Results Scientists keep records of their observations, or data: i.e. drawings, typed on computers, online storage ZScientists use the data from an experiment to evaluate a hypothesis and draw a valid conclusion. ZRedi’s results supported the hypothesis that maggots were produced by flies, not spontaneous generation Drawing a Conclusion

25. Repeating Investigations: Spallanzani's Test of Redi's Findings Gravy is boiled. Scientists repeat experiments to be sure that the results match those already obtained.

26. Repeating Investigations Spallanzani's Test of Redi's Findings Flask is open. Flask is sealed.

27. Repeating Investigations Spallanzani's Test of Redi's Findings Gravy is teeming with microorganisms. Gravy is free of microorganisms. Which is the manipulated / responding variable? Q X

28. Repeating Investigations Pasteur's Test of Spontaneous Generation o Louis Pasteur conclusively disproved the hypothesis of spontaneous generation. o Pasteur showed that all living things come from other living things.

29. 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.

30. 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.

31. 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. No theory is considered absolute truth. As new evidence is uncovered, a theory may be revised or replaced by a more useful explanation.

32. 1–2 Section Quiz In an experiment, the variable that is deliberately changed is called the a)control. b)manipulated variable. c)responding variable. d)constant control

33. 1–2 Section Quiz The mistaken belief that living organisms can arise from nonliving matter is called a)biogenesis. b)Pasteur's theory. c)spontaneous generation. d)Spallanzani’s hypothesis.

34. 1–2 Section Quiz Which of the following was the manipulated variable in Redi’s experiment? a)the kind of meat used b)the temperature the jars were kept at c)the gauze covering on some jars d)the kind of fly that visited the jars

35. 1–2 Section Quiz A well-tested explanation that unifies a broad range of observations is a a)hypothesis. b)variable. c)control. d)theory.

36. 1–2 Section Quiz A scientific explanation does not become a theory until a.a majority of scientists agree with it. b.it has been supported by evidence from numerous investigations and observations. c.it is first proposed as an explanation. d.it is published in a textbook.

37. Bios = __________ Logos = _______________ Study of biodiversity Study of living organisms (structures and their functions) and Interactions between living organisms (ecology) life word/the study of WHAT IS BIOLOGY?

38. 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.

39. What are some similarities? What are some differences?

40. Living things share the following characteristics : Organization: Cells, tissues, organs, systems Homeostasis: the maintaining of a stable internal environment Response to a stimulus: changes to environmental factors Growth and Development: changes in an organism over time (also evolve) Reproduction: transmission of hereditary information from one generation to the next Based on Universal Genetic Code Perform Metabolism: using materials and energy.

41. 1-3 An increase in size is known as a)growth. b)metabolism. c)development. d)differentiation.

42. 1-3 Which of the following is NOT a characteristic of all living things? a)use of energy b)made of cells c)stable internal environment d)need for oxygen

43. 1-3 Which of the following are branches in the study of biology? a)cells, tissues, organs, and organisms b)botany, cell biology, ecology, and zoology c)populations, communities, and ecosystems d)the genetic code, evolution, and the biosphere

44. 1-3 The genetic code is carried in a)Water. b)DNA. c)proteins. d)soil.

45. 1-3 Which of the following shows the levels of organization in correct order from the simplest to the most complex? a)organisms, cells, populations, molecules, ecosystems b)ecosystems, populations, organisms, cells, molecules c)molecules, cells, organisms, populations, ecosystems d)molecules, organisms, cells, populations, ecosystems

46. Van Leeuwenhoek’s first microscope Cork cells

47. The compound- microscope today:

48. Ocular lens Tube Body Arm Revolving Nosepiece Low power High power Scanning power Objectives Stage clips Stage Disc diaphragm Condenser lens Coarse adjustment knob Fine adjustment knob Light Base

49. Effect of Lens on image If object looks like ‘ d ’; then image will look like d d d d b

50. Objective lenses 4X10X40X Glass Slide “Working distance” of each lens from the slide - distance at which image is in focus Size of objects in “field of view” as seen through the ocular lens Amount of slide “seen” by each objective lens = field of view e e e e e

51. How to focus your microscope Center the object over the condenser lens. Select the low power (10X) objective. Raise the stage as high as it will go. Look through ocular lens and slowly lower stage with coarse adjustment knob until object is in focus. Center the image in your field of view. Rotate nosepiece until 40X “clicks” into position. While looking, use fine adjustment knob ONLY to bring image into final focus. NOTE: once one lens is in focus, the other two are nearly in perfect focus -- the microscope is parfocal.

52. Slide Object 4X Focal Plane A 10X B 40X C Once in focus, each lens will stay in focus!

53. Measuring objects with the microscope Use a metric ruler to measure the field of view of 10X. 1 mm = 1,000 micrometers (µm) How many µm is the 10X diameter? ___________ 2,000 µm 1mm 10 X

54. 10X field of view Problem: How long, in µm, is the organism?

55. 10X Move slide so that organism is at edge of field of view. Approximate how many organisms will stretch across the diameter. 4 imaginary + 1 real = 5 organisms stretch across 2000 µm. 2000/5 = 400 Therefore, each organism must be about ________µm long. Solution to problem 400

56. Scanning Electron Microscope (SEM) Up to 500,000x Only the surface of objects can be seen. Lets see how it works

57. SEM We need to treat the object to help it survive the vacuum pressure.

59. We need to make the object electron sensitive, so we coat it with a fine mist of gold.

60. Ready for scanning.

61. Place object on mounting tray and close vacuum sealed door

62. Scanning Electron Microscope (SEM)

63. SEM Images

64. Scanning Electron Microscope (SEM) Fly Eye

65. Scanning Electron Microscope (SEM) Inside of Stomach Surface of Tongue Neuron

66. Scanning Electron Microscope (SEM) Pollen Yeast Red Blood Cell, Platelet, and White Blood Cell

67. Transmission Electron Microscope (TEM) 150x to 400,000x

68. Transmission Electron Microscope (TEM) Herpes Virus Plant Root Cell

69. TEM vs. SEM Viruses leaving a cell

70. STM Scannning Tunneling Microscope Can look at atoms on the surface of things! Very itty bitty tiny small.

71. Review for Chap 1 Test Terms: Development, adaptation, homeostasis, evolution, reproduction, environment Observation, hypothesis, experiment, data, conclusion, theory, natural law Science, qualitative data, quantitative data Skills Wet mount slide, use of microscope

72. If an object looks like this: d on a slide, then its image through the microscope should look like: p d db A microscope has a 10X ocular lens, and a 50X objective lens, what is the total magnification of the image? If an organism appears through the microscope as seen below, how would you move the slide in order to center the organism in the field of view? Up and to the right

73. Parts and functions of compound microscope Coarse/fine adjustment knobs, diaphragm, revolving nosepiece When do you use a stereoscopic dissection microscope vs. a compound microscope? Why does the image become dimmer when you change from 10X to 40X? In order to raise your microscope stage for focusing, do you turn the adjustment knob toward or away from yourself? Before changing from 10X to 40X, what must you do regarding the image you are observing?

74. What is the nature of the “control” portion of an experiment? What are the main characteristics which identify something as “living”? What does “mass” refer to? What kinds of things qualify as “stimuli” to living organisms?

75. Let’s practice!

76. Which scope made the image? A BC

77. Do well on your test :) That’s all...

78. End of presentation