1 Chapter 1- The Science Of Biology

2 I. What is Science A. What Science is and is Not. 1. The goal of science is to investigate and understand the natural world, to explain events in the natural world, and to use those explanations to make useful predictions.

3 2. Science deals with ONLY the natural world. 3. Scientists collect and organize information in a careful way looking for connections between events. 4. Science is an organized way of using evidence to learn about the natural world.

4 B. Thinking like a scientist 1. Scientific thinking usually begins with observations. 2. The information is gathered as data.

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6 3. Two types of data are quantitative data (expressed as numbers) and qualitative data (descriptive and characteristics). 4. Scientists infer- which is a logical interpretation based on prior knowledge.

7 C. Explaining and Interpreting evidence 1. A hypothesis is a proposed scientific explanation for a set of observations.

8 D. Science as a Way of Knowing 1. Scientists are always trying to discover new things all the time. 2. They are always questioning facts.

9 E. Science and Human Values 1. Science helps to protect human life.

10 II. How Scientists Work A. Designing an Experiment 1. Ask a question. 2. Form a hypothesis

11 3. Set up a controlled experiment. In a controlled experiment only one variable is tested at a time. a. The variable can be manipulated. b. The variable that is observed and that changes in response to the manipulated variable is called the responding variable.

12 4. Record and Analyze results. 5. Draw a conclusion.

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14 6. Publish and repeat the investigation. a. Leeuwenhoek discovered “ animalcules ” swimming in a pond of water. It was a large debate- where they always there or was it spontaneous generation. b. Because of publishing work, others challenged the work. c. Pasteur tested spontaneous generation.

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16 B. When Experiments are not possible. 1. Researchers have to design an alternative investigation.

17 C. How a Theory develops 1. The word theory applies to a well-tested explanation that unifies a broad range of observations. 2. A theory enables scientists to make accurate predictions about new situations.

18 III. Studying Life A. Characteristics of Living things. 1. Living thing are made up of cells. 2. Living things reproduce. (Either sexual or asexual) 3. Living things are based on a universal genetic code. (Offspring usually resemble their parents)

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20 4. Living things grow and develop. 5. Living things obtain and use materials and energy. 6. Living things respond to their environment.

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22 7. Living things maintain a stable internal environment. (Homeostasis) 8. Living things change over time. (Evolution)

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24 B. Branches of Biology 1. See page 21 in textbook.

25 IV. Tools and Procedures A. Common measurement System 1. Most scientists use the metric system when collecting data and performing experiments. 2. See figure 1.23 for conversions.

26 B. Analyzing Biological Data 1. When scientists collect data, they are trying to find out if certain factors changed. A graph is used to illustrate this.

27 C. Microscopes 1. Light microscopes produce magnified images by focusing visible light rays. Electron microscopes produce magnified images by focusing beams of electrons. 2. There are two main types of microscopes- light microscope and an electron microscope.

28 Light microscope left Electron micrscope right

29 D. Laboratory Techniques 1. Cell cultures are formed when a scientist takes a sample and the cell is able to reproduce so that a group of cells can be studied. 2. Cell fractionation is used to separate the different parts of a cell.

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31 The End