Chapter 1 The Science of Biology

1. Chapter 1The Science of Biology 1-1: What is Science

2. What science is and is not… • KeyC#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 • Investigate • Explain • Make predictions • Three features of science: • 1. In the context of the natural world • 2. Data collection is organized (look for patterns/connections) • 3. Must be testable by looking at evidence • Def: Science—an organized way of using evidence to learn about the natural world.

3. Thinking like a scientist • Scientific thinking: • Def: Observation—use of senses to gather information (data) in an orderly fashion • Data: • Quantitative—expresses as numbers (counting/measuring) • Qualitative—descriptive characteristics (cannot be counted) • What are some examples of quantitative vs. qualitative? • Scientists use data to make inferences. • Def: Inference—logical interpretation based on prior knowledge or experience (ex. water in reservoir)

4. Explaining and Interpreting Evidence • After initial observations of the natural world, researches will propose a • Def: Hypothesis—proposed scientific explanation for a set of observations • Hypotheses rise from: • Prior knowledge • Logical inference • Informed, creative imagination • Must be testable. Can be ruled out or supported/confirmed.

5. Science as a way of knowing • The best scientists are skeptics • Don’t be afraid to ask questions. • Questions both existing and new hypotheses. • There are limits to science and definite lines that should not be crossed. What do you think determines where these lines are drawn? • First question in the bible: Genesis 3:1 • “Now the serpent was more crafty than any of the wild animals the Lord God had made. He said to the woman, ‘Did God really say, ‘You must not eat from any tree in the garden’?’”

6. Writing assignment: Where is the line? • Write a paragraph (5 complete sentences, TS, 3 SS, CS) explaining why Jenner’s research methods might have been controversial and whether you support/challenge his methods. • Edward Jenner video

7. Chapter 1The Science of Biology 1-2: How scientists work

8. Designing an experiment • First: Ask a question. (i.e. how did maggots get on the meat? Spontaneous generation?) • Def: Spontaneous generation: life from non-living matter • Second: Form a hypothesis. (i.e. maybe maggots come from flies) • Remember: observe and propose an explanation • Setting up a controlled experiment • Variables: factors that can change (i.e. equipment used, materials, temperature, light, time) • KeyC#1: 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. • Controlled experiment: • Manipulated variable: changed by the researcher • Responding variable: changes in response to the manipulated variable • Let’s look at Figure 1.8 (Pg. 9)

9. Designing an experiment cont’d… • Recording & Analyzing Results: • Always keep a record of your data (hard copy/digital) • What types of data can we observe? • Drawing a conclusion: • Data is used to refute for support the hypothesis. • Remember: have integrity! Do not manipulate your data! • Repeating experiments: • Your work is a contribution to the science community • Let’s look at Figure 1-11, pg. 12 • How did Pasteur’s test add to Redi’s experiment? What was his conclusion?

10. When experiments are not possible • Other ways of testing a hypothesis: • Field studies • Clinical studies (i.e. cancer-causing chemical) • How a theory develops: • Well supported hypothesis can become a theory • Def: Theory—well tested explanation that unifies a broad range of observations • Remember: a theory cannot be considered as absolute truth. Why?

11. Chapter 1The Science of Biology 1-3: Studying life

12. Characteristics of living things • Def: Biology—The science that employs the scientific method to study living things • KeyC#1: Living things share the following characteristics… • Made up of units called cells • Reproduce • Based on a universal genetic code • Grow and develop • Obtains and use materials and energy • Respond to their environment • Maintain a stable internal environment • Change over time

13. Big Ideas in Biology: Timeline of our learning… • Science as a way of knowing • Interdependence in nature • Matter and energy • Cellular basis of life • Information and Heredity • Unity and diversity of life • Evolution • Structure and Function • Homeostasis • Science, Technology, and Society • What idea are you most excited about learning?

14. Branches of Biology • KeyC#2: Some of the levels at which life can be studied include: • Molecules • Cells • Groups of cells • Organisms • Populations • Communities • Ecosystems • Biosphere • Complete your flowchart! Hole punch and keep in your handouts divider!  • Biology is a part of your every day life! (p. 22)

15. Chapter 1The Science of Biology 1-4: Tools and procedures

16. A Common Measurement System • KeyC#1: Most scientists use the metric system when collecting data and performing experiments. • Metric System • Decimal system • Based on physical standards • Scaled on multiples of 10 • Let’s look at figure 1-21 (p. 24) • How do scientists collect data?? • What is the purpose of a graph or table?

17. Microscopes • Microscopes—devices that produce magnified images of structures that are too small to see with the unaided eye • KeyC#1: Light microscopes produce magnified images by focusing visible light rays. Electron microscopes produce magnified images by focusing beams of electrons. • Read Appendix D! • Light Microscopes: • View living things 1000x magnified • Electron Microscopes: • View smaller non-living or dead samples with more detail than light micro. • TEM: inside of cells • SEM: surface of cells

18. Laboratory Techniques • Cell culturing: growing a single cell into many cells (cell culture) • Cell fractionation: separate cell parts (blend & centrifuge)